Did search....no idea?! Trans or T-case?

I have a 94 xj w/ 4.0, aw4 auto., 231 case, 3 1/2" lift. No sye yet. Front 30 and rear 8.25.

My problem is when running have bad shaking/vibes.

Gear - Park, 2wd or 4wH or 4wL no shakes
Gear - N, 2wd or 4wH or 4wL no shakes
Gear - OD, 2wd feel a little bit of shakes
Gear - OD, 4wH more shakes than 2wd
Gear - OD, N case no shakes
Gear - OD, 4wL lots o' shakes

I'm wondering if its the T-case or Trans? I am thinking of getting a T-case out of the J-yard and rebuilding it with the SYE kit i have. Putting a new chain in it. Could the case be the culprit?

Surprised you would need a SYE with a 3.5 lift, but each xj is different.

Just for fun, have you inspected your transmission/transfer case mount? Have you inspected the u-joints and checked the driveshaft(s) for dents/missing weights?

MPH figuers with those shakes might help in diagnosis.

The SYE Kit install would be in prep for the extra lift that i plan on putting on, to get to 4.5/5" total.

I should have mentioned that all these shakes are when the vehicle is just sitting stationary with my foot on the brake. Not moving at all. All i'm doing is putting it through the gears.

I did just replace my motor mounts (they went bad after the last wheeling trip a month ago) and my tranny mount (did that one 4 days ago).

This just seems to get worse as time goes on. Especially after the tranny mount. I know i put it in right, cant really mess that one up. It even did it while on the last wheeling trip a month ago so when i replaced the motor mounts after finding they were bad, i would have thought it would have gotten better.

Ok, the more info the better.

Engine running, not moving, shakes--loose torque converter bolts? Could it be a cylinder misfire under load? Electricity will take the easiest path to ground--check cap and rotor condition, inspect and/or spray test the sparkplug wires.

I think the easiest thing to check forst would be the T-case and drive shafts. Check all the u-joint bolts on the drive lines to make sure they are tight. Seen those come loose after a a good trip. Had a similar experiance in a Z-71. If you have someone you can trust Hav ethem go through the gears while laying under the vehicle, or if you dont like them make them lay under there while you go through the gears just incase something goes wrong. Maybe you can put eyes on the problem (or ears).

Well I did just that yesterday at work. I had my buddy who just became a member of go through the gears in 4Lo and i looked under the vehicle. Everything torques a whole lot, but thats normal when theres so much load on the drivetrain components and trying to hold them stationary. I am thinking there is something going on in the T'case. Loose chain possibly?

Like i said earlier, i will be putting a SYE in my truck and i am pretty sure i will pick one up at the local PnP, rebuild it on the bench and install the SYE. That way i can put a nice new chain in it if its bad. This truck is my DD and i use it every day, so if i can have a T'case ready and just swap with the one in my truck now, then it wouldnt leave me down for too long.

I know the feeling, My DD is sitting out front with tranny, T-case off. All because of a bad slave cylinder. My help had to go to work and im not gonna crush myself with the tranny.


That would be the safe route. if its shaking that bad, that would be my guess.

Yeah that whole assembly isnt the lightest thing in the world. even with a floor jack i would still want someone else around to help balance it too! So good idea to wait.

If nothing is turning, i.e., driveshafts, transmission shafts and gears, transfer case chain, shafts, gears--what is shaking and/or vibrating? Good engine and transmission mounts, as you said, then what is going on? Like you said bad tc case chain, maybe bad trans clutches?

Bad trans clutches.......could be. Very good idea sir. Will be wheeling this weekend so have to see if anything breaks, then we'll point a finger <------ and say "thats the problem".