Bought my '98 Limited Cherokee with a 3.5 Rubicon lift and (Rusty's ?)full pack springs which are shimmed. It came with a hack n tap SYE and CV driveshaft.
Due to a lot of drivetrain noise and vibration, I had a Tom Wood's driveshaft and SYE kit installed and the leaf packs re-shimmed. Still had bad vibration under hard acceleration. Had T-case inspected (242) and it was going bad. Replaced it. Rear diff (LSD) turned out to have problems too, so had it rebuilt (Front diff rebuilt also).
After all that the noise is gone, but there is still a bad vibration under hard acceleration. What else is there to check? The shop that did all the work said they played with different pinion angles, ran it with front driveshaft removed etc. and could not get rid of vibration. Thanks in advance.

 

bad tire, bent rim, bent axle, warped brake drum

 

Does the vibe go away when you let off the gas? If so then it's not your driveshaft/pinion angles. Check motor and tranny mounts and ujoints.

 

if the shop you used threw all that at it and can't give you a straight answer find a better shop..i doubt half that stuff was bad they were just covering themselves for misdiagnosing the noise.. that lift isn't big enough to cause big problems. under acceleration won't be a wheel or tire normally, could be wheel hop.. how hard are you tromping the gas?

 

Last time I drove it, the vibration would stop if you let off the gas. You could feel vibes under moderate acceleration, and if you stomped on it the whole truck would shake...it felt like axle wrap. They have had my truck for over a month....I am going to test drive it tomorrow morning before I pay for all the work (they said they would cut out a lot of the labor).
Thanks for the advice. I will report back tomorrow with the details.

 

automatic? i had a torque converter go to s#$% on a ford truck for a customer and it had similar affects only under load it shook hard.....never seen it again but something to think about

 

mine vibrates only when i get it to 40-45 mph only i dont get it

 

I had a very similar experience except with a TH-350. Old trans blew up on my way to the airport. No time to screw with it (didn't want to miss my flight) so I had it towed to a trans shop, anticipating a correct repair waiting for me when I returned from my trip.


Awful vibration on acceleration. Trans shop supposedly went through everything... in the end I wound up fixing it myself, and it turned out to be the torque converter.

 

if its speed related it could be a tire move them around on the truck see if the shake moves

 

Got truck back today. Still vibration under hard acceleration. The shop did find a bad motor mount and replaced it (but did not do the other one...). The overall vibration at cruising speed is not noticeable. I am going to pull my camper with it and see how it performs under load.
What is alarming is that the bad bearing sound it had before is still there ...it's noisy and increases with speed...it sounds like I am running big mudder tires.
(What's worse is that the rebuilt T-case is already weeping from the front output seal...it's got 3 miles on it.) Needless to say it is going back to the shop tomorrow.

 

wheel bearings...front u-joints, i'd be putting a whoopin on the guys you got workin on it..

 

I was wondering what you paid for all that work? If you don't mind telling.

 

powerbrake your xj and watch the pinion on the rearend. if there is excessive movement take a good look at your leaf springs