Jerry Bransford

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:3FF246C3.7B6E3D82@***.net...
> Would you believe the '02 Factory Repair Manual has it pictured:
> http://www.----------.com/03TJCV.pdf I guess they forgot to follow their
> engineers.
> God Bless America, ßill O|||||||O
> mailto:--------------------
>
> Matt Macchiarolo wrote:
> >
> > Don't discount the role of the CV joint on the driveshaft, which the
Rubicon
> > does not have in stock form.

You're right that the rear driveshaft we're talking about is not a CV
driveshaft. It's only the front driveshaft on a '97 or newer Wrangler that
has a CV joint.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at http://members.***.net/jerrypb/

Jerry Bransford

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:3FF246C3.7B6E3D82@***.net...
> Would you believe the '02 Factory Repair Manual has it pictured:
> http://www.----------.com/03TJCV.pdf I guess they forgot to follow their
> engineers.
> God Bless America, ßill O|||||||O
> mailto:--------------------
>
> Matt Macchiarolo wrote:
> >
> > Don't discount the role of the CV joint on the driveshaft, which the
Rubicon
> > does not have in stock form.

You're right that the rear driveshaft we're talking about is not a CV
driveshaft. It's only the front driveshaft on a '97 or newer Wrangler that
has a CV joint.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at http://members.***.net/jerrypb/

Jerry Bransford

"L.W. (ßill) ------ III" <----------@***.net> wrote in message
news:3FF246C3.7B6E3D82@***.net...
> Would you believe the '02 Factory Repair Manual has it pictured:
> http://www.----------.com/03TJCV.pdf I guess they forgot to follow their
> engineers.
> God Bless America, ßill O|||||||O
> mailto:--------------------
>
> Matt Macchiarolo wrote:
> >
> > Don't discount the role of the CV joint on the driveshaft, which the
Rubicon
> > does not have in stock form.

You're right that the rear driveshaft we're talking about is not a CV
driveshaft. It's only the front driveshaft on a '97 or newer Wrangler that
has a CV joint.

Jerry
--
Jerry Bransford
To email, remove 'me' from my email address
KC6TAY, PP-ASEL
See the Geezer Jeep at http://members.***.net/jerrypb/

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

That's why he sells a shorty: http://www.4xshaft.com/shorty.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jerry Bransford wrote:
>
> Bill, I'm sure even you would have to agree that Tom Wood at Tom Wood's
> Custom Driveshafts has forgotten more about such stuff than either you or
> I... Tom also disagrees with you where he says:
>
> "Many people mistakenly believe that a double cardan or C.V. type drive
> shaft will allow for greater operating angles than a conventional 2 joint or
> single cardan drive shaft. This is not true. Some types of C.V.'s will
> actually incur a binding interference at less of an angle than a standard
> two joint drive line, again depending on the individual components used.
> Additionally the C.V. itself is longer than more conventional components and
> will create a greater operating angle on the driveline, especially on very
> short shafts."
>
> The above was from Tom Wood's Tech Info page at http://www.4xshaft.com/
>
> Since I am CERTAIN you will argue the point, do so with Tom Wood since he is
> the guy that set me straight years ago when I was mistaken about the same
> subject. Tom has a nifty email form you can fill in and send him the
> information that will prove him wrong.
>
> Jerry
> --
> Jerry Bransford
> To email, remove 'me' from my email address
> KC6TAY, PP-ASEL
> See the Geezer Jeep at
> http://members.***.net/jerrypb/

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

That's why he sells a shorty: http://www.4xshaft.com/shorty.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jerry Bransford wrote:
>
> Bill, I'm sure even you would have to agree that Tom Wood at Tom Wood's
> Custom Driveshafts has forgotten more about such stuff than either you or
> I... Tom also disagrees with you where he says:
>
> "Many people mistakenly believe that a double cardan or C.V. type drive
> shaft will allow for greater operating angles than a conventional 2 joint or
> single cardan drive shaft. This is not true. Some types of C.V.'s will
> actually incur a binding interference at less of an angle than a standard
> two joint drive line, again depending on the individual components used.
> Additionally the C.V. itself is longer than more conventional components and
> will create a greater operating angle on the driveline, especially on very
> short shafts."
>
> The above was from Tom Wood's Tech Info page at http://www.4xshaft.com/
>
> Since I am CERTAIN you will argue the point, do so with Tom Wood since he is
> the guy that set me straight years ago when I was mistaken about the same
> subject. Tom has a nifty email form you can fill in and send him the
> information that will prove him wrong.
>
> Jerry
> --
> Jerry Bransford
> To email, remove 'me' from my email address
> KC6TAY, PP-ASEL
> See the Geezer Jeep at
> http://members.***.net/jerrypb/

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

That's why he sells a shorty: http://www.4xshaft.com/shorty.html
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

Jerry Bransford wrote:
>
> Bill, I'm sure even you would have to agree that Tom Wood at Tom Wood's
> Custom Driveshafts has forgotten more about such stuff than either you or
> I... Tom also disagrees with you where he says:
>
> "Many people mistakenly believe that a double cardan or C.V. type drive
> shaft will allow for greater operating angles than a conventional 2 joint or
> single cardan drive shaft. This is not true. Some types of C.V.'s will
> actually incur a binding interference at less of an angle than a standard
> two joint drive line, again depending on the individual components used.
> Additionally the C.V. itself is longer than more conventional components and
> will create a greater operating angle on the driveline, especially on very
> short shafts."
>
> The above was from Tom Wood's Tech Info page at http://www.4xshaft.com/
>
> Since I am CERTAIN you will argue the point, do so with Tom Wood since he is
> the guy that set me straight years ago when I was mistaken about the same
> subject. Tom has a nifty email form you can fill in and send him the
> information that will prove him wrong.
>
> Jerry
> --
> Jerry Bransford
> To email, remove 'me' from my email address
> KC6TAY, PP-ASEL
> See the Geezer Jeep at
> http://members.***.net/jerrypb/

Tim Hayes

Great link! Thanks!

So:

- A larger u-joint angle means a more elliptical path for the driveshaft
ends of the two joints.

- This causes a greater velocity variance as the joint turns through
every 180 degrees.

- The changes to velocity require acceleration/deceleration of the shaft.

- Acceleration/deceleration requires the application of force to the shaft.

- The changing forces are felt as vibration in the system.

Tim Hayes

Great link! Thanks!

So:

- A larger u-joint angle means a more elliptical path for the driveshaft
ends of the two joints.

- This causes a greater velocity variance as the joint turns through
every 180 degrees.

- The changes to velocity require acceleration/deceleration of the shaft.

- Acceleration/deceleration requires the application of force to the shaft.

- The changing forces are felt as vibration in the system.

Tim Hayes

Great link! Thanks!

So:

- A larger u-joint angle means a more elliptical path for the driveshaft
ends of the two joints.

- This causes a greater velocity variance as the joint turns through
every 180 degrees.

- The changes to velocity require acceleration/deceleration of the shaft.

- Acceleration/deceleration requires the application of force to the shaft.

- The changing forces are felt as vibration in the system.

TJim

The stock TJ *does* have a 2nd u-joint. It's just closer to the 1st u-joint
than it needs to be, since the slip joint is outboard of the driveshaft
instead of in the middle. This results in a shorter driveshaft and higher
angles and therein lies the problem.
The advantage of the CV joints is twofold. First, they allow (require) the
u-joint on the other end to be aligned differently (because of the second
advantage), raising the pinion and reducing the angles of the driveshaft.
Second (and the reason for the first, above), they don't accelerate and
decelerate the driveshaft with each revolution (since they are made of two
out of phase u-joints), which is part of the cause of the vibrations in the
first place. That's why they are called "constant velocity" joints.
--
Jim
--
98 TJ SE
90 SJ GW
http://www.delawareja.com/gallery/JDJeep98
"You can do any job in the world with the wrong tool if you try hard
enough..."
"4x4" in caps is "$X$"


"Tim Hayes" <thayes@remove-me.rutgers.edu> wrote in message
news:3ff20db9@rutgers.edu...
> Isn't the angle only an issue in two ways?
>
> 1) a u-joint has a maximum angle it can operate through
>
> 2) the angle on both ends of a 2 u-joint driveshaft must be the same
>
> Since a stock TJ doesn't have a second u-joint won't you always violate
> #2 except at one specific ride height (and even then whenever you flex
> over a bump)?
>
> Couldn't you correct #2 by adding the second u-joint without lengthening
> the driveshaft provided you don't violate #1?
>
> This is all from my mechanical engineering classed in college so maybe
> I've got it wrong. It isn't like i've ever actually built a drivetrain
> myself, but I thought I understood the theory pretty well.
>
> Jerry Bransford wrote:
>
> > Tim, it's not the slip yoke itself that causes vibrations, it's only the
> > driveshaft angle that does. That the Rubicon has moved the slip yoke to
the
> > driveshaft doesn't change the lift height that will cause drivetrain
> > vibrations. That the Rubicon has a slightly longer driveshaft due to the
> > elimination of the t-case slip yoke will help though. :)
>