94 cherokee, had a 242 transfer in it, was about to fail on me, so my buddy parted out his 96, he had a rebuilt 231 in it with an advance adapt sye, about 8 mos old, never wheeled, and it drove good to, no vibes. I put the same transfer/drive shaft (front cv style shaft) with new joints in it, now i get vibes at 50,55, sometimes 60 mph... Both xj's had the same trans behind it, i counted the splines to ensure everything would jive, checked, everything is tight and nothing was left overlooked while re-assembling. Am i missing something???

 

Your pinion angle.. sounds like you need to check what your rear driveline is operating at.

 

Well... i am roughly at 4.75/5in on lift, the whole lift was new,(no exxageration, shipping labels still on the leaf packs) came off a cash for clunker jeep at the junk yard fo 85 bucks, anyways, didnt know who the maufacturer was and not sure the rate or size of springs, at the time i was at 3 inches with crappy coils and blocks. So, the rear leafs had angle shims on there, so i left them on, could that be an issue when running a sye??? again, i THINK, but am not sure about lift size, before with blocks, i couldn't fit a coke can between the tire and bottom of flare, now, i have about a 7-9 in gap between top of tire and bottom i=of the flare, tires are 31 bfg at's with 50% tread if it matters.... Thanks for the response!!!!!

 

Check those pinion angles. I did a she and still had. Vibes until I checked
My angles and did the proper wedges to shim it

 

I cant link directly, go here and read about the rear driveshaft operating angles on standard and cv style rear shafts. Pick up angle finder and see where your at. You probably need to add or subtract a shim to your leafpack to dial in.

http://www.4xshaft.com/

 

Thanks!!!!! ill be messing with it this week, i now have a mysterious oil press issue to tackle.... JeeP... This S$!t never ends!!!!!

 

Sounds like pinion angle to me, ay as well check the front drive-line CV joint too. mine would vibe about 50-60mph when it wore out.

 

Im actually running sans front shaft, cause i forgot to pick up extra hardware for the rear shaft....Doh... fail!