grinding noise on lifted XJ

I have a 3.5inch full springs lift kit on my 2001 XJ and there is a somewhat faint "grinding" or "rough humming" coming from what sounds like the rear axle. I only hear it when I let off the gas at 35mph or above. I am going to install a transfer case lowering kit to eliminate some acceleration vibrations. WIll this help the "grinding". Any other ideas.

just a thought, but how are your differential and tcase fluids?

more than likley it is due to driveline angles. On a 01 you may need, and would be much better off insatalling a SYE and CV shaft. Newer XJ's seem to be more pickey.

if it is driveline angle that's causing your problem, you can adress that with shims and or tcase drop. FYI, a motor mount lift works the same as a tcase drop.

If you have the extra money to spend, do it right and get the sye and cv shaft. At 4-500 its not cheap.

I herard of a lot of people having good luck with the RE hack and tap, and front DS combo. Do a search. I have a 1" T-case drop and Bastard pack, about 6" with no vibes or binding using my stock DS. Its for a D35 but I switched to a 8.25 (from 01) The D35 driveshaft is a little longer so the yolk is fine. I plan to swap this but it's ok for now. It is a 90 though with the old output on the T case, less subject to vibes, more likely to leak...LOL