Jeff Strickland

The 3.73 is better than the 3.07 for offroading. Why not change the front to
match the new rear?

And, you issue isn't the pumkins, it's the carriers. The pumpkin is the
outside housing of the differential, the carrier is the part that holds the
ring gear. You can swap the 3.07 carrier and ring gear into the pumpkin that
now houses the 3.73 carrier and gear.




"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A3BB49EFDsomeconundrum@216.196.97.131. ..
>I swapped out a Dana 35 rear axle and differential on a 1997 TJ to repair a
> bent axle tube from a collision. The donor axle was unfortunately
> configured for a 3.76 ratio with the Trac-Lok limited slip, versus the
> original that was 3.07 with no locker. I want to change the old ring and
> pinion into the new differential case to get back to 3.07, otherwise we
> have no 4WD due to the mismatch between front and rear.
>
> My question is whether the 3.07 and 3.76 housings ("pumpkins") are the
> same, so that I can just fit all the old moving parts from the old 3.07
> assembly into the new 3.76 housing. I don't want to open up the cover on
> the new assembly if the bearing seats or something are incompatible. If I
> can just swap, what one-time items will I need, such as the crush sleeve,
> ring bolts, and/or shims?
>
> I've disassembled the old assembly, including taking out the differential
> case out of the housing with a ------er tool, per the manual.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A65F3CE00someconundrum@216.196.97.131. ..
> Richard J Kinch writes:
>
>> So I can swap the whole differential (what you're calling the carrier)
>> into the new housing?
>
> Sorry, should have said "differential case", not just differential. The
> "differential case" is the item that holds the ring gear, pinion mate
> gears, and side gears. The "axle housing" is the pumpkin shell.

Yes, you can set the 3.07 carrier into the differential housing. The
subordinate parts are the same, so some can be used again if they are in
good condition, but some must be replaced.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A65F3CE00someconundrum@216.196.97.131. ..
> Richard J Kinch writes:
>
>> So I can swap the whole differential (what you're calling the carrier)
>> into the new housing?
>
> Sorry, should have said "differential case", not just differential. The
> "differential case" is the item that holds the ring gear, pinion mate
> gears, and side gears. The "axle housing" is the pumpkin shell.

Yes, you can set the 3.07 carrier into the differential housing. The
subordinate parts are the same, so some can be used again if they are in
good condition, but some must be replaced.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A65F3CE00someconundrum@216.196.97.131. ..
> Richard J Kinch writes:
>
>> So I can swap the whole differential (what you're calling the carrier)
>> into the new housing?
>
> Sorry, should have said "differential case", not just differential. The
> "differential case" is the item that holds the ring gear, pinion mate
> gears, and side gears. The "axle housing" is the pumpkin shell.

Yes, you can set the 3.07 carrier into the differential housing. The
subordinate parts are the same, so some can be used again if they are in
good condition, but some must be replaced.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A6A8442A7someconundrum@216.196.97.131. ..
> JimG writes:
>
>> I would have went the other way... change the front to 3.76... better
>> gearing and a limited slip in the rear!
>
> That's still an option, but would require buying another gear set (or even
> the whole case?) and install kit.

Gear set and carrier.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A6A8442A7someconundrum@216.196.97.131. ..
> JimG writes:
>
>> I would have went the other way... change the front to 3.76... better
>> gearing and a limited slip in the rear!
>
> That's still an option, but would require buying another gear set (or even
> the whole case?) and install kit.

Gear set and carrier.

Jeff Strickland

"Richard J Kinch" <kinch@truetex.com> wrote in message
news:Xns9898A6A8442A7someconundrum@216.196.97.131. ..
> JimG writes:
>
>> I would have went the other way... change the front to 3.76... better
>> gearing and a limited slip in the rear!
>
> That's still an option, but would require buying another gear set (or even
> the whole case?) and install kit.

Gear set and carrier.

Jeff Strickland

"Earle Horton" <el_anglo_burgues@usa.com> wrote in message
news:45808bb8$0$15460$88260bb3@free.teranews.com.. .
> 3.73 is one of the "good" ratios. Almost as good as 4.10, which is the
> "best" stock ratio you can get. My advice is to drive the vehicle some,
> to
> see how you like the new gear ratio.
>

I like this idea the best. Drive the 3.73s for a couple of weeks. If you
like them, buy more 3.73s for the front.

Frankly, you're looking at the same amount of work to swap the rear gear set
back to 3.07 as to swap the front set to 3.73. The 3.73 is a better ratio,
and for my money is worth the cost. Since you are convinced you can do the
work yourself, then you have no labor cost. But if you had same labor cost,
it would be the same to swap the front set or swap the rear set, so labor is
a moot point whether you do it or pay to have it done. Your only cost-up to
swap the front is that you have to buy parts that you don't already own, but
I think the investment is well worth the money.




> As far as swapping the ring and pinion, it is doable, but setting the
> pinion
> depth, pinion bearing preload, ring gear backlash and carrier bearing
> preload are rightly considered "expert" tasks. If you don't do it right,
> noises and reduced part life. If you do decide to keep the 3.73, then you
> will need a 3.73 ring and pinion, a different carrier and probably an
> install kit. The "carrier" is the part with the spider gears inside.
>
> Earle
>
> "Richard J Kinch" <kinch@truetex.com> wrote in message
> news:Xns9898A6EFEEA66someconundrum@216.196.97.131. ..
>> Richard J Kinch writes:
>>
>> > The donor axle was unfortunately configured for a 3.76 ratio
>>
>> Oops, that should be, "3.73".
>
>
>
> --
> Posted via a free Usenet account from http://www.teranews.com
>

Jeff Strickland

"Earle Horton" <el_anglo_burgues@usa.com> wrote in message
news:45808bb8$0$15460$88260bb3@free.teranews.com.. .
> 3.73 is one of the "good" ratios. Almost as good as 4.10, which is the
> "best" stock ratio you can get. My advice is to drive the vehicle some,
> to
> see how you like the new gear ratio.
>

I like this idea the best. Drive the 3.73s for a couple of weeks. If you
like them, buy more 3.73s for the front.

Frankly, you're looking at the same amount of work to swap the rear gear set
back to 3.07 as to swap the front set to 3.73. The 3.73 is a better ratio,
and for my money is worth the cost. Since you are convinced you can do the
work yourself, then you have no labor cost. But if you had same labor cost,
it would be the same to swap the front set or swap the rear set, so labor is
a moot point whether you do it or pay to have it done. Your only cost-up to
swap the front is that you have to buy parts that you don't already own, but
I think the investment is well worth the money.




> As far as swapping the ring and pinion, it is doable, but setting the
> pinion
> depth, pinion bearing preload, ring gear backlash and carrier bearing
> preload are rightly considered "expert" tasks. If you don't do it right,
> noises and reduced part life. If you do decide to keep the 3.73, then you
> will need a 3.73 ring and pinion, a different carrier and probably an
> install kit. The "carrier" is the part with the spider gears inside.
>
> Earle
>
> "Richard J Kinch" <kinch@truetex.com> wrote in message
> news:Xns9898A6EFEEA66someconundrum@216.196.97.131. ..
>> Richard J Kinch writes:
>>
>> > The donor axle was unfortunately configured for a 3.76 ratio
>>
>> Oops, that should be, "3.73".
>
>
>
> --
> Posted via a free Usenet account from http://www.teranews.com
>

Jeff Strickland

"Earle Horton" <el_anglo_burgues@usa.com> wrote in message
news:45808bb8$0$15460$88260bb3@free.teranews.com.. .
> 3.73 is one of the "good" ratios. Almost as good as 4.10, which is the
> "best" stock ratio you can get. My advice is to drive the vehicle some,
> to
> see how you like the new gear ratio.
>

I like this idea the best. Drive the 3.73s for a couple of weeks. If you
like them, buy more 3.73s for the front.

Frankly, you're looking at the same amount of work to swap the rear gear set
back to 3.07 as to swap the front set to 3.73. The 3.73 is a better ratio,
and for my money is worth the cost. Since you are convinced you can do the
work yourself, then you have no labor cost. But if you had same labor cost,
it would be the same to swap the front set or swap the rear set, so labor is
a moot point whether you do it or pay to have it done. Your only cost-up to
swap the front is that you have to buy parts that you don't already own, but
I think the investment is well worth the money.




> As far as swapping the ring and pinion, it is doable, but setting the
> pinion
> depth, pinion bearing preload, ring gear backlash and carrier bearing
> preload are rightly considered "expert" tasks. If you don't do it right,
> noises and reduced part life. If you do decide to keep the 3.73, then you
> will need a 3.73 ring and pinion, a different carrier and probably an
> install kit. The "carrier" is the part with the spider gears inside.
>
> Earle
>
> "Richard J Kinch" <kinch@truetex.com> wrote in message
> news:Xns9898A6EFEEA66someconundrum@216.196.97.131. ..
>> Richard J Kinch writes:
>>
>> > The donor axle was unfortunately configured for a 3.76 ratio
>>
>> Oops, that should be, "3.73".
>
>
>
> --
> Posted via a free Usenet account from http://www.teranews.com
>