TwoXJS

Hey, guys! Back again with new findings....Been working to solve a bad vibe in my '93 XJ. Tried just about everything I found to try with little success. Today, just out of the blue, I decided to pull my T-Case drop kit out. Just has little spacer bracket things on either side of the cross-member.

Took them out, bolted it back up and took it for a drive. Immediately noticed it drives quite a bit smoother! Even shifts easier now that the shifter is in the proper location! Does still vibrate a little at speed, but not as harsh. Normally would feel it start around 45, but didn't feel much of anything this time.

However, a new issue popped up on the drive....A groaning sound coming from the rear of the vehicle. Only heard starting from a stop and a little accelerating in second. After it gets up to speed, it's gone until the next time you stop. I've got an extra U-Joint in my toolbox ready to go in, but I'm not sure if this would indicate a bad one.

Is there a specfic way to check them to see if they're bad, or do you think this is something more complicated? By the way, the vibration isn't really felt through the steering. It's much more of a whole vehicle, seat of the pants vibration

TwoXJS

Anyone?

bulrid8

With the TC drop removed, your driveline angle may be to steep now. That may be causing the groan sound.

The vibration you had with it in, may have been a ujoint going out. Need to check the angles on rear pinion and drive shaft and see where they sit.

ck1

Motor mounts fixed two issues in my Heep...i was chasing vibes on mine for awhile...it turned out to be motor and trans mounts...i also had a tc drop, 2 degree shim and was eating joints about every 4-6 months..i replaced my mounts and vibes while driving were way worse...took out the tcase drop and shims no vibes whatsoever...so you may want to replace the three mounts and see...it cant hurt...i have no vibes going down the road or at idle (which caused me to get mounts to begin with)...drove me nuts to feel the engine vibes thru the whole jeep at idle...the driveline vibes drove me nuts as I knew I was going to have to put joints in soon again..the new mounts put the driveline in factory position and it is now very smooth all the time
just a thought
Cameron

TwoXJS

So, how would I go about checking the angle and mounts?

EDIT: Found a good guide on how to do it and it doesn't look that hard. Found the mounts on RockAuto, so just may end up doing that.

TwoXJS

So, I had to do a little driving today and noticed a couple things....First off, it seems I got the location of this noise wrong. It actually seems to be coming from the front end. It seems to be a groaning/rumbling sound that only happens when taking off from a start. Harder acceleration= louder noise.

What could this point to? If I can tomorrow, I'll go for another short drive and have my phone camera recording from inside so it can be heard, maybe that'll help. Also, not sure if it might be connected, it seems my front axle pinion has a lot of play in it. Driveshaft is off right now and I can turn it nearly a full inch to either side. Discovered this while I was greasing fittings....

TwoXJS

Alright, think I got this figured out. Seems MOST likely to be the exhaust hitting the cross-member. Looked up underneath today and there's MAYBE an 1/8" gap between them, so makes sense. That, and it started right after removing the drop kit....

As for the vibration, I think I got it mostly solved today. I was checking my two new front wheel bearings and noticed when I was turning the driver side, the entire knuckle was moving up and down! Turns out the axle shaft joint was locked up....It would move free one way, but not the other. Three caps shattered apart when pressing it out, not to mention needle bearings rusted together.

Put a new one in, low and behold, the vibration's mostly gone. Still does a bit over 60, but not NEARLY as much. Enough to make some screws in the rear ashtray rattle pretty good. Before, I never took it over 60 to be safe....Took it to almost 80 today! Feels good letting the angry squirrels really play....