XJ shim amount

[bushman67]

Ok guys... got a question. I'm sure someone out there in XJ build land has done this, and may know the amount of shim needed. My T-Case drop didn't entirely solve my drive line vibe, and I'm going install an SYE in about a month, but still need a temporary fix. I really don't want to have to buy/try various shim sizes to get it dialed in either.

So, barring measuring all my angles (which I may have to do anyway) I'll ask out trusty XJ knowledge base first.

-- 96 XJ, NP242, 8.25 rear end.
-- Lifted with 3.5" gear, but netted 5" above showroom stock measurements. (currently on 235s)
-- 1.5" t-case drop
-- vibration starts at 40, build to 60-70, then ease off as you climb to 100.

It's probably a crapshoot either way, as I read that so many people have different [vibration] results in doing the same lifts.

Thoughts? Anyone use their iPhone level app to measure driveline angles?

[Waytec]

I shimmed mine 8 degrees I think it was a long time ago now. I got 3 different sizes from modern and asked right off the bat if I don't use them can I return them. I paid cash so I think they left them off the books for a couple days and then I returned the 2 I did not use on Monday. I do remember using the smallest one and that fixed everything. I never did use a t-case drop.
Did you also mention that your pinion baring is shot. that would case vibrations, also have a really good look at you bushing and suspension parts, is everything taking grease properly, are your wheel bearings good, is your drive shaft have a weight missing from it or a good dent in the side.
Good luck with the hunt.

[bushman67]

The original D35 was shot, I swapped in an 8.25 that's pretty tight and right now am only running the 1.5" t-case drop, but still have enough vibes that I wouldn't run it much... just a quick lap around Cochrane was enough.

I'll try and do some measurements tomorrow to see if I can calculate it, unless someone else chimes in with some similar numbers... 6 or 8 is what I'm thinking.

From what I've read, theoretically the angle of the drive shaft at each end should be equal, less 1~2 deg downturn on the pinion. Correct?

[Zombie]

I think I have about a 6 degree shim in mine right now with about a 4.5-5 inch lift or so and it is a little too small and I think I need to get the 8 degree shims.
I do not get vibrations until about 110 km/hour though.
I would suspect some kind of play in the bearings.

when I picked mine up, almost everything in the front end was shot(steering, bearings, elongated drag link hole on the knuckle, worn ball joints and replacing all that took all the lower end vibs out, not the rear is a little bit out from where it should be and needs attention when I change the rear springs out.

good luck.

steve

[Bnine]

Cut the perches off and buy some new ones from standens.

Locate the axle on the new perches with the correct driveline geometry. 

Weld in new perches.

Try to avoid using degree shims. They have a tendency to break apart, and subsequently spit out while on the trail.

[GiS]

Cut the perches off and buy some new ones from standens.

Locate the axle on the new perches with the correct driveline geometry. 

Weld in new perches.

Try to avoid using degree shims. They have a tendency to break apart, and subsequently spit out while on the trail.

X 100..It's really fun getting off the trail once you just spit your shims ....

[jpthing]

I'm sure bnine is speaking from experience but I pounded on a set of RE Steel dgree shims for over 3 years before swapping out to a different setup and they lokked as good as the day they went in, just rustier, in fact I sold them to one of the guys on here. Also, it's really nice to be able to try different angles without cutiing grinding and welding. I got rid of my XJ SYE and went with a lengthened TJ driveshaft which has worked really well for me and would not have been as easy a mod to do had I modified my rear axle to suit the SYE.

8 degrees sounds like a lot to me...I have around 4" lift and tried 4 and 6 degrees and ended up going with the 4 degree shim. I have a set of 6 degree shims still for sale in the FS forum if you are interested.

I guess you could carry a spare set of shims if you were worried, they're cheap and small.

[Zombie]

I will let you know boone as to what I have.
I didn't put them in so I am more or less just guessing, but for some reason that is what I thought.

it may only have 4 degree shims.

who knows!!

I will have to have a look later.

I just dropped the jeep off with Lemon-aid jay to get some work done on the front.

but I will have a look when I get it back and try to figure it out.

[Bnine]

The last set of RE's I used were aluminum.

Second week the guy had them in the split and proceeded to walk the axle off the leaf.


Depends on how you wheel though. If you arent going to wheel that hard, they woud probably be fine.

Between that, and the fact that with xj's shtty suspension bias, the rear doesnt move much, you might be alright.

Personally, I wont put them in for people, thats just me.  What ever you do, dont forget to re torque your ubolts.

[bushman67]

These shims are really only for a temp fix until I get the SYE in place, and at that time, I will probably have the perches cut & welded. Down the road I would like to put in a D44 w/ disc brakes + locker...

[cLAY]

Bushman,

I think I have a set of shims in my junk pile that you can try if you like. I'm in Cochrane(Glenbow) so it would be easy for you to pick up.

Let me know if you want them and I'll try to find them.

[bushman67]

Really? Crap. I'm actally enroute to Modern for brake lines and shims. What size are they? I'm just over in heritage hills.  BTW do you know of a built up white XJ and a red XJ? I know the white one lives here but the red one has just started coming around. 

[cLAY]

Hmm sorry no idea what degree they are.

There was a white one around the corner from me awhile ago but havn't seen it in quite awhile so I think he sold it. I've seen the red one as well as a blue one.

Mine is a black ZJ with red axles, hard to miss.

[bushman67]

I talked with the guys at Modern and they figure my vibe is the front because of the 242 tcase & it's drop actually buggered my front geometry.  My current measurements are perfect. The diff is 1deg down from the tcase. Im pulling the front drivehaft and taking it for a run. If my vibe is gone. Well back to the drawing board. Remove the tcase drop. Re measure and shim the rear.  

However they say there is no SYE for a 242 except doing the hack & tap. Odd as I got a quote from J on a full blown sye kit for the 242.

Think I just came up with a name for my XJ.   "Ned".  Needs Every Dollar.  

[apeman]

Soooo did you get rid of the tcase drop after all?  Did the vibe go away?