Hey guys,

Got a 2000 XJ with the AW4 and 150k miles on the clock.

Noticed a rumble/shaking in the tranny when stationary in reverse after an unusually cold start for the first a week ago. It disappeared in neutral and drive and only happened in reverse, however disappeared when I actually reversed.
At first I thought it was just cold fluid not doing its thing fast enough early in the morning and forgot about it.

It made another appearance again today, I let the jeep warm up, drove it around a bit, but was still happening.
I've attached a video link for reference - obviously ignore the squeaking and listen for the rumbling/shaking, which disappears when I put it in drive or neutral. I can feel the shaking/vibration in the tranny tunnel.

https://www.youtube.com/watch?v=C-m1...ature=youtu.be

*** These are things you can rule out:
- Tranny fluid perfectly full
- Tranny mount; replaced 4 months ago
- T-case shifter linkage; Already have that noise, definitely isn't it that
- Checked the flexplate many many times before, no cracks or loose bolts, however haven't had the motivation to check again.
- Exhaust pipes are solid.
- I pumped out ALL the fluid and replaced it with fresh dextron III about 5k miles ago (didn't have it flushed, just let the tranny pump it out while I added fresh stuff until it ran pink)

I know usually these things end up being trivial problems...I really hope this one is too!

Any idea's guys?

 

That sounds really ugly. Have you checked your U-joints?

I'm reaching here.... Somethign does not like having torque in the reverse direction. Transfer case? Front or rear diff? But you aren't in 4WD, so it's not the front.... Still could be in the t-case.

If you have a helper, I suggest a mechanic's stethoscope and some crawling under the vehicle. Put it up on stands and set the parking brake. Create the noise and get your eyeballs and stethoscope going different places.

 

Exhaust hitting crossmember ?

 

@RudeXJ have you found the cure for this by chance? My 96 started doing this so I'm curious

 

Look and see if the exhaust is rattling against the cross-member. Usually caused by a bad trans or motor mounts.

 

That sounds really ugly. Have you checked your U-joints?

 

OP said it's noticeable when sitting still in reverse, so probably not u-joints.