Calling AW4 wizzards - reverse rumble (VIDEO LINK)

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 (only happens when stationary) after a particularly cold start for the first time a week ago. It disappeared in neutral and drive and only happened in reverse, however disappeared when I actually reversed and would return when I stopped whilst in reverse.

At first I thought it was cold fluid not doing its thing fast enough early in the morning as it went away after a few minutes of idling.

It made another appearance again today, I let the jeep warm up, drove it around a bit, but was still happening. However it did eventually go away after everything was well warmed up driving around the block a couple times, but took much longer to disappear than before it seemed.

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-m1U-TRemE

*** 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)

Am I just being paranoid or is this something to worry about?

Would dearly appreciate your brain juice on this.

Rudi

That sounds like something with the motor mounts and/or exhaust!

I agree, but then why does it only occur in reverse?
Not park, neutral, or drive?

Your reversing which way the motor torques.

Wait what? I didn't know that?

So you reckon its motor mounts? Would make sense because it happened after a day of driving terrible corrugated dirt roads.

Is there a way to test your motor mounts without replacing them?

RudeXJ said:

Wait what? I didn't know that?

So you reckon its motor mounts? Would make sense because it happened after a day of driving terrible corrugated dirt roads.

Is there a way to test your motor mounts without replacing them?

Click to expand...

Watch how much the engine moves while someone puts it in gear and taps the throttle with their foot firmly on the brake. Could just be a rock or crap jammed in the motor mount too.

Here is the first place to look.

https://imgur.com/Hqp3XPI

SOLVED: Like so many noises in the past, completely harmless...feel like a bit of an idiot.

Once I got someone in the jeep, slammed in reverse I looked around for clearances and found t-case was hitting/vibrating off the skid plate - I have a 3 inch lift with t-case drop brackets.

*Intersesting note, when put in reverse the whole transmission actually drops a couple millimetres.

Thanks for the help guys

I would look into a "good" set of motor/tranny mounts!

Yep you're probably right. I've replaced trans mount a couple months ago, but wasn't the best quality....Its on the list, but first got a couple other pressing issues.