Adapting cardan joint to stock slip yoke

[XJguy]

cbremer, TRNDRVR, do you remember the part number of the special yoke you guys used and did anything have to be modified on the stock driveshaft itself to fit the cardan joint in?

I spoke to someone at Tom Woods and what he told me did not convince me in the least bit that this is not a good option. His most critical element was that if my driveshaft has to be removed I will lose all my fluid....easily remedied with a coke bottle and a large hose clamp or zip tie.

XJguy

 

[Slip Kid]

I would assume the shaft would need to be shortened. definately, you're adding another u-joint and extra space.

Also, you won't lose all the fluid, a baggie and a rubber band will catch the little bit that comes out. as for driving it fwd without a rear shaft that could be a problem. but in that situation you're screwed anyway right?

I'd be all over this setup if I hadn't just gone through the trouble to get a longer d-shaft. I'll wait till I have vibes, then I'll more than likely try this before a SYE, being the cheap bastid I am.

 

[BLUTO]

adapting cardan joint to stock slip yoke

I got hooked-up with a VERY experienced mechanic/parts supplier through Chrysler's transmission labs. I explained what we were discussing on this forum and his experience seems to confirm the various comments and opinions that are being aired on this subject.
Basically, you can use a CV or double-cardan type joint to control vibes on mildly (<4") lifted vehicles. It should work fine. The downside to this is: you are cantilevering more weight off the TC's output shaft and that will cause rear bearing failure on a "quicker than OEM application" frequency. This means that yes, you may have a bearing failure that "could" scramble your TC and other various attached components. Lots of articulation (off-road rock climbing) does not help this scenario along either.
This mod is best used by DD's who see little or none off-roading.

What I got from this is: if you have a lot of $$$ tied-up in your rig OR do a lot of heavy off-roading, then stay with the SYE. If you are on a firm budget, mostly DD, and don't mind the increased risk to your output shaft bearings.....then this may be your set-up!
I will now have to save-up a little longer to get rid of the last of my vibes.

BLUTO

 

[Eagle]

Re: adapting cardan joint to stock slip yoke

Your summary is mostly correct, but seems to ignore the reality of the two different transfer case output designs. Although the early design doesn't have a bearing at the end of the tail cone, it does have a seal that the slip yoke rides in to help control what Stryker calls "runout" -- that's the more correct term, but I generally think of it and refer to it as "whip." The '96 and newer output shaft has a long and totally unsupported out put shaft. That's more problemmatic.

Many people run up to 4" of lift with no vibes on the old style output design. Virtually nobody runs ANY lift without vibes on the new style. Bluto, if you work at DC you must know that with the new style, even the factory Up Country suspension creates vibes, and the factory authorizes dealers to install transfer case drops to address this (if you cal masking the symptoms "addressing" the problem).

For those who might still consider this, especially with the new style transfer case, just hanging a double-cardan joint off a slip yoke is not the answer. You also want to address that runout issue, and short of a SYE the best way is to shorten the output shaft as much as possible, fix the yoke or double cardan joint as close to the transfer case body as possible (like the RE "hack 'n tap" SYE), and modify the drive shaft to put the slip splines in the drive shaft rather than on the output shaft.

If you have ever watched a u-joint or even a double-cardan joint operate at extreme angles, you know that if the shafts are unrestrained the "knuckle" tends to want to bind up and move laterally (or off the axis of rotation). It's the output bearing that resists and restrains this, and that's why you need the output sgaft to be as short as possible, and the yoke or joint as close to the bearing as possible -- to reduce the effective lever arm of this eccentricity (or runout) on the output shaft.

I got hooked-up with a VERY experienced mechanic/parts supplier through Chrysler's transmission labs. I explained what we were discussing on this forum and his experience seems to confirm the various comments and opinions that are being aired on this subject.
Basically, you can use a CV or double-cardan type joint to control vibes on mildly (<4") lifted vehicles. It should work fine. The downside to this is: you are cantilevering more weight off the TC's output shaft and that will cause rear bearing failure on a "quicker than OEM application" frequency. This means that yes, you may have a bearing failure that "could" scramble your TC and other various attached components. Lots of articulation (off-road rock climbing) does not help this scenario along either.
This mod is best used by DD's who see little or none off-roading.

What I got from this is: if you have a lot of $$$ tied-up in your rig OR do a lot of heavy off-roading, then stay with the SYE. If you are on a firm budget, mostly DD, and don't mind the increased risk to your output shaft bearings.....then this may be your set-up!
I will now have to save-up a little longer to get rid of the last of my vibes.

BLUTO

 

[vintagespeed]

Like some of the other guys have said, this is a retarded idea. Adding a double cardan joint to the end of your slip yoke will only INCREASE your operating angles due to the extra length of the joint itself. All this extra weight at now-increased angles will most likely cause a binding issue & trash your junk. Save up a few dollars more & DO IT RIGHT. If you're looking for a cheap solution to your vibes, check your angles first! Most of the guys that complain about problems haven't even crawled under their Heep to examine it. Then get a SYE & new driveshaft & enjoy the fact that you DID IT RIGHT.

 

[XJguy]

So basically it all boils down to leverage. The leverage on the stock SY is already at its limits, adding the double cardan joint just gives more weight for the bearings to deal with. I follow you all. But its a short term solution that works, you have to admit that much.

XJguy

 

[ChuckD]

So basically it all boils down to leverage. The leverage on the stock SY is already at its limits, adding the double cardan joint just gives more weight for the bearings to deal with. I follow you all. But its a short term solution that works, you have to admit that much.

XJguy

Unforuatately I have to agree with Vintage, , If your over 6" of lift, I believe that's waht were talking about here. The only real solution would be the SYE. I understand what your trying to do, and you say your going to take it easy at MOAB. If you show up this way, please bring an extra Tcase to swap in. Or of course the alternative, is to do it right and get the SYE.

I'm not trying to discount this solution, but I think it would be more approrpiate with lifts under 6".

 

[BrettM]

you guys need to just sell your XJs and get MJs I have 8 inches of lift and don't need an SYE at all, I do have a YJ slip yoke and my Toy8" has a little longer pinion snout. My driveshaft angle is probably still better than the XJ I used to have with 3.5"

 

[Eagle]

So basically it all boils down to leverage. The leverage on the stock SY is already at its limits, adding the double cardan joint just gives more weight for the bearings to deal with. I follow you all. But its a short term solution that works, you have to admit that much.

XJguy

It may be a short term solution, but if it eats your output bearings and destroys the transfer case, I'd hardly consider that to be a short term solution "that works."

 

[BLUTO]

Re: Re: adapting cardan joint to stock slip yoke

[ Bluto, if you work at DC you must know that with the new style, even the factory Up Country suspension creates vibes, and the factory authorizes dealers to install transfer case drops to address this (if you cal masking the symptoms "addressing" the problem).

[/B]

Yes, I do work at DC....not as an engineer (thank GOD......no put-down intended to engineers; the beancounters really hobble the engineering dept. ) I am employed as a Pipefitter....I take care of the heat/cool, plumbing, and process piping for approx. 5M FT2 of R&D + offices at Chrysler Tech Center in Auburn Hills, MI
I used to work at Jeep-Truck Engineering about 12 yrs ago,...that's the place to work if you own a Jeep product!
Working there gives me SOME insight as to what is coming-up, I went for a ride in a HEMI WJ on our test track earlier this summer! The new one looks quite a bit like the old one, maybe a little bigger.

I will save my coin and buy the SYE kit, I own a 2000 XJ Limited with only 42K miles. It is my DD and I want to keep it intact (somewhat) until I can afford to make the XJ my second vehicle. Going thru a de-wifeing mod right now, some of you may know how expensive that can be!

Thankyou for your input Eagle,

BLUTO