Lug nut torque & warped rotors
01-09-2006, 01:19 PM
#71
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
On the last set of studded snow tires I bought (late 70's) the tire
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
01-09-2006, 01:19 PM
#72
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
On the last set of studded snow tires I bought (late 70's) the tire
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
01-09-2006, 01:19 PM
#73
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
On the last set of studded snow tires I bought (late 70's) the tire
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
installer twisted off two of the lugs on one wheel with his impact wrench.
The manager came out to the waiting area to explain there would be a delay
and the repair would be at no charge.
I wandered around back and watched the repair.... The new studs were
installed and I listened to the metal groan as the hammer tightened the lug
nuts.
When the manager came to get me I asked to see the car, opened the trunk and
handed the lug wrench to the manager and asked him to loosen the lugs after
explaining what I had seen.
This burly man had no chance with the factory lug wrench and none still when
he tried a large 4 way .
They were loosened with an air gun and the manager tightened them with a 4
way and I went on my way until about 10 miles later as I slid through an
intersection. Luckily there was not a collision as few vehicles were out
and upon examination I noticed there were NO studs in the tires.
I returned to the shop a bit peeved both at the shop for the prior problems
and for installing the incorrect tires and myself for not noticing the
missing studs.
"Earle Horton" <NurseBustersNoSpam@msn.com> wrote in message
news:43c221ae$0$3022$6d36acad@roc.nntpserver.com.. .
> People forget that an impact wrench is more like a hammer, than it is like
> a
> torque wrench. If you hold it on for a shorter or longer time, you get
> looser or tighter fasteners, no matter what the dial setting. It is a
> little like hammering nails into a board. They keep going in, little by
> little, even if you just tap on them. Impact wrenches can deform
> fasteners
> too, so it is better to always use a manual wrench (if the fasteners are
> not
> too tight!).
>
> Earle
>
> "DougW" <post.replies@invalid.address> wrote in message
> news:Zzkwf.41621$---.11135@dukeread07...
>> Spdloader did pass the time by typing:
>> > Wrong or right, my information came from a school Chrysler gave on
>> > their
>> > braking systems I attended in 1996.
>> >
>> > Cost is most often the driving factor, I think. Spend the least they
>> > can
> get
>> > away with.
>>
>> <major snippage>
>>
>> I run stillen rotors on the ZJ after the OEM pieces of ---- gave way and
> warped.
>>
>> As a rule I never let anyone torque the lugnuts but me. I even take my
> own
>> torque wrench to the tire dealer and tell them to spin the nuts on by
>> hand
>> and I'll finish them off. No if's and's or but's.
>>
>> The other thing to remember is the types of lugnuts. Cone, flat, and
> shoulder.
>> Crank the wrong ones too tight and you can crack the rim.
>>
>> As the wrencher who taught me said, "Air guns are for taking stuff off if
> your
>> too weak to do it by hand." :) -------, yes, but he could have taught
>> a
> monkey
>> to yodel.
>>
>> --
>> DougW
>>
>>
>
>
01-09-2006, 02:19 PM
#74
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Interesting. I had Brembo disks on my Alfa, and they recommended against
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
01-09-2006, 02:19 PM
#75
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Interesting. I had Brembo disks on my Alfa, and they recommended against
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
01-09-2006, 02:19 PM
#76
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Interesting. I had Brembo disks on my Alfa, and they recommended against
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
slow braking as it caused the disk to heat up and warp. In fact, the way you
were meant to bed them in was by a few hard stop and go's
Dave
--
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"Spdloader" <askforit@nospam.triad.rr.com> wrote in message
news:Frkwf.4183$Kp.274@southeast.rr.com...
> Wrong or right, my information came from a school Chrysler gave on their
> braking systems I attended in 1996.
>
> Cost is most often the driving factor, I think. Spend the least they can
get
> away with.
>
> Spdloader
>
>
>
> "Jerry Bransford" <jerrypb@***.net> wrote in message
> news:Cojwf.8771$V.4697@fed1read04...
> > Klutz and Spdloader,
> >
> > Composite rotors used for several years on Jeeps were not installed by
the
> > factory to lessen rotor warping. They were a cost-reduced and
> > significantly lightened rotor that warped so easily that Jeep went back
to
> > all-cast rotor. They were so light in weight that they weren't able to
> > resist warping from both heat and uneven lugnut tightening. Newer
> > Wranglers and JGCs have all-cast rotors that are far better able to
> > resist heat and uneven-tightening induced warping.
> >
> > Jerry
> >
> > klutz wrote:
> >> Your explanation is clear, but difficult to accept.
> >>
> >> "Spdloader" <askforit@nospam.triad.rr.com> wrote in message
> >> news:rlhwf.4160$Kp.3269@southeast.rr.com...
> >>
> >>>The rotors on your GC are made from two parts, the rotor, and the
"hat".
> >>>The hat is the part of the rotor that the wheel studs go through and
your
> >>>wheels bolt to. Further, the hat of the rotor rests flat against the
> >>>wheel hub assembly, and you'll not warp that with 250ft. lbs of torque,
> >>>much less the 125 you specified finding. The hat uses a different type
of
> >>>metal from the metal in the rotor, specifically to keep lug nut torque
> >>>from being an issue with the rotors.
> >>
> >>
> >> If the manufacturer changed the rotors to a 2-piece design with
> >> dissimilar metals to guard against problems caused by over/under
> >> torquing, why in the world have they continued to ignore the
> >> cross-section thickness of the rotor? I agree that a thicker rotor
> >> (e.g., Brembo) will minimize the probability of warpage. If Jeep's
> >> engineers were genuinely concerned about the component, they would have
> >> re-engineered all known weaknesses, including warpage. I have to
applaud
> >> Jeep's technology of rotor assembly. The joint between the 2 rotor
> >> pieces is absolutely indetectable to the naked eye.
> >>
> >>
> >>>Jeep changed over to this type of rotor during the first series of GC
and
> >>>has used them since.
> >>
> >>
> >> Jeep recognized the advantages of the Akebono caliper in 2002. When
were
> >> the rotors changed to a 2-piece model?
> >>
> >>
> >>>Lug nut torque was not the cause of the warpage on your rotors, hasn't
> >>>been an issue in brake rotor warpage for years, but the general public
> >>>won't let go of the idea.
> >>
> >>
> >> If that's true, why does Jeep provide a recommended torque range for
lug
> >> nuts? Service procedures would be simpler for everyone if the
> >> manufacturer's specification was "85 lbs/ft minimum, user selects
> >> maximum".
> >>
> >>
> >>>The tire installer is not to blame.
> >>
> >>
> >> You say that random torquing wasn't a contributing factor, so that
makes
> >> the tire installer's methods sound? Hell, even the tire busters at
> >> Costco use a torque wrench. If it didn't matter, would Costco bother?
> >>
> >>
> >>>The rotors being too thin to start with, along with driving habits,
stop
> >>>and go or city driving, and overdriving the brakes (driving too fast,
> >>>stopping at the last moment) are the most often the cause of brake
> >>>pulsations, like it or not.
> >>
> >>
> >> Not in this case. The Jeep is babied. Driving habits are excellent.
A
> >> Ford Thunderbird we owned previously (which was notoriously known for
> >> rotor warpage) didn't exhibit any brake problems in 40,000 miles,
likely
> >> because of proper driving habits.
> >>
> >>
> >>>The variations in lug nut torque are not out of line in the real world,
> >>>rust, contamination, imperfect threads, grease, and dirt all affect the
> >>>torque of the lug nuts. In perfect, laboratory conditions, with
perfectly
> >>>clean studs and nuts, lightly oiled, and a perfectly calibrated torque
> >>>wrench, you might get 'em close, but that's not the real world.
> >>
> >>
> >> I guess I'm pickier than most, because I refuse to use an impact wrench
> >> on the lug nuts of any of my vehicles. Interestingly, the Jeep is the
> >> only vehicle I've owned that needed rotor replacement before it needed
a
> >> brake job.
> >>
> >>
> >>>By the way, with aluminum or magnesium wheels, lug nuts should be
> >>>retorqued after driving 50 to 100 miles. ALWAYS.
> >>
> >>
> >> You're right about that one. I learned that back in the 70s, when I
> >> worked for Chrysler. I still have the same Snap-On Torqometer that I
> >> used back then to torque lug nuts, including vehicles with left-handed
> >> threads on the left side.
> >>
> >>
> >>>Spdloader
> >>>
> >>>
> >>>"klutz" <klutz@klutzville.net> wrote in message
> >>>news:Azdwf.8592$V.4423@fed1read04...
> >>>
> >>>>My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
> >>>>completing the repairs, I'm surmising that her driving style didn't
> >>>>cause the problem. While removing the lug nuts with a breaker bar, I
> >>>>felt a disparity in the effort required to loosen them. Hmmm. That
> >>>>can't be good. I wondered what the torque was on the other wheel, so I
> >>>>used a torque wrench to loosen the lugs. Torque varied from 80 to 125
> >>>>lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
> >>>>wheels. Same sad shape. Torque was all over the map. Moral of the
> >>>>story - when the dealer is doing warranty work (power window) and asks
> >>>>if you want your tires rotated - tell 'em "No, thanks" - unless you
can
> >>>>oversee the job. Incidentally, the old rotors and pads had 29,000
miles
> >>>>and wore evenly, with no glazing or hot spots. The pads have 5/16 of
> >>>>friction material left. My money says that the dealer's tire-jockey
has
> >>>>caused me (and likely many others) to suffer from warped rotors.
> >>>>Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
> >>>>has rotors made of soft cast iron. Inattention to wheel torque can
> >>>>destroy them in a heartbeat.
> >>>>
> >>>
> >>>
> >>
> >>
> >
> > --
> > Jerry Bransford
> > PP-ASEL N6TAY
> > See the Geezer Jeep at
> > http://members.***.net/jerrypb/
>
>
01-09-2006, 02:19 PM
#77
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Yes ! So it isn't just me !
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
01-09-2006, 02:19 PM
#78
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Yes ! So it isn't just me !
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
01-09-2006, 02:19 PM
#79
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
Yes ! So it isn't just me !
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
Dave Milne, Scotland
'91 Grand Wagoneer, '99 TJ
"DougW" <post.replies@invalid.address> wrote in message
news:Zzkwf.41621$---.11135@dukeread07...
> As a rule I never let anyone torque the lugnuts but me. I even take my
own
> torque wrench to the tire dealer and tell them to spin the nuts on by hand
> and I'll finish them off. No if's and's or but's.
01-09-2006, 08:02 PM
#80
Guest
Posts: n/a
Re: Lug nut torque & warped rotors
On Mon, 09 Jan 2006 03:05:18 GMT, "Spdloader"
<askforit@nospam.triad.rr.com> wrote:
>
>Costco "bothers" in order to keep the wheels from falling off and getting
>sued. It happens more than you think. W/O's, (wheel offs) were the number 2
>problem with a vehicle with "mags" after a brake job for comebacks, right
>behind brake squeal as complaints go for #1.
Tell me about it! I had the left rear wheel come off my '80 lwb Dodge
van in the wee hours one morning (it was loaded heavily with vending
machine merchandise and had a full 36-gallon plastic tank to boot)
after getting new tires. I found that the lug nuts had to torqued to
100 ft/lbs. Twice more, I nearly all four wheels simultaneously until
I checked with a dealer about the torque spec (turbine-style aluminum
wheels). I found that it is a frighteningly common occurrence, with
service station mechanics the usual culprits. It seemed every 5th or
6th person I talked to had had it happen to them or a family member.
It isn't that critical on steel rims, however, and my '77 Cherokee
only requires 75 ft/lbs.
>>
>>> "klutz" <klutz@klutzville.net> wrote in message
>>> news:Azdwf.8592$V.4423@fed1read04...
>>>> My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
>>>> completing the repairs, I'm surmising that her driving style didn't
>>>> cause the problem. While removing the lug nuts with a breaker bar, I
>>>> felt a disparity in the effort required to loosen them. Hmmm. That
>>>> can't be good. I wondered what the torque was on the other wheel, so I
>>>> used a torque wrench to loosen the lugs. Torque varied from 80 to 125
>>>> lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
>>>> wheels. Same sad shape. Torque was all over the map. Moral of the
>>>> story - when the dealer is doing warranty work (power window) and asks
>>>> if you want your tires rotated - tell 'em "No, thanks" - unless you can
>>>> oversee the job. Incidentally, the old rotors and pads had 29,000 miles
>>>> and wore evenly, with no glazing or hot spots. The pads have 5/16 of
>>>> friction material left. My money says that the dealer's tire-jockey has
>>>> caused me (and likely many others) to suffer from warped rotors.
>>>> Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
>>>> has rotors made of soft cast iron. Inattention to wheel torque can
>>>> destroy them in a heartbeat.
From what I've been told, all the newer vehicles do, and at least some
factory rotors are also too thin to be turned.
Dan
>>>>
>>>
>>>
>>
>>
>
<askforit@nospam.triad.rr.com> wrote:
>
>Costco "bothers" in order to keep the wheels from falling off and getting
>sued. It happens more than you think. W/O's, (wheel offs) were the number 2
>problem with a vehicle with "mags" after a brake job for comebacks, right
>behind brake squeal as complaints go for #1.
Tell me about it! I had the left rear wheel come off my '80 lwb Dodge
van in the wee hours one morning (it was loaded heavily with vending
machine merchandise and had a full 36-gallon plastic tank to boot)
after getting new tires. I found that the lug nuts had to torqued to
100 ft/lbs. Twice more, I nearly all four wheels simultaneously until
I checked with a dealer about the torque spec (turbine-style aluminum
wheels). I found that it is a frighteningly common occurrence, with
service station mechanics the usual culprits. It seemed every 5th or
6th person I talked to had had it happen to them or a family member.
It isn't that critical on steel rims, however, and my '77 Cherokee
only requires 75 ft/lbs.
>>
>>> "klutz" <klutz@klutzville.net> wrote in message
>>> news:Azdwf.8592$V.4423@fed1read04...
>>>> My wife's 2003 Grand Cherokee fell victim to warped rotors, but after
>>>> completing the repairs, I'm surmising that her driving style didn't
>>>> cause the problem. While removing the lug nuts with a breaker bar, I
>>>> felt a disparity in the effort required to loosen them. Hmmm. That
>>>> can't be good. I wondered what the torque was on the other wheel, so I
>>>> used a torque wrench to loosen the lugs. Torque varied from 80 to 125
>>>> lb/ft on the R/F wheel! Just for safety's sake, I checked the rear
>>>> wheels. Same sad shape. Torque was all over the map. Moral of the
>>>> story - when the dealer is doing warranty work (power window) and asks
>>>> if you want your tires rotated - tell 'em "No, thanks" - unless you can
>>>> oversee the job. Incidentally, the old rotors and pads had 29,000 miles
>>>> and wore evenly, with no glazing or hot spots. The pads have 5/16 of
>>>> friction material left. My money says that the dealer's tire-jockey has
>>>> caused me (and likely many others) to suffer from warped rotors.
>>>> Intentionally, perhaps? Hard to prove. Word to the wise - the 2003 WJ
>>>> has rotors made of soft cast iron. Inattention to wheel torque can
>>>> destroy them in a heartbeat.
From what I've been told, all the newer vehicles do, and at least some
factory rotors are also too thin to be turned.
Dan
>>>>
>>>
>>>
>>
>>
>