I have this 2000 4.0l 4x4 almost complete. I am down to NVH. There are basically 2 issues that I am dealing with that are kinda getting the better of me. Maybe they are one in the same but it's hard to tell. I have the boom noise at idle ( the TSB has been done for the exhaust and pcm update) Also a harshness coming from the rear mount area. Has anyone had any experience replacing the factory trans mount with one that has the brace welded in? (i guess it's a safety deal in case the mount fails) It seems to me it would be noisy as it connects both pieces of the mount together or am I missing something. I currently have a cheap one from NAPA in there which does not have the brace but although it is better than the original that had failed, it still has some seat of the pants vibration which can really be felt when ascending or descending Mountain highways. When I disconnect and manipulate the trans mount I can temporarily dissipate the condition but within a couple of days it comes back making me think it's the mount. If anyone has any experiences out there they could share it would be appreciated. And lastly does anyone know the correct rear drive shaft angles in degrees. Would appreciate that as well. As I said I have pretty much completed this project. Engine completely resealed, trans out and resealed same with the transfer case, front suspension completely replaced steering gear included, rear suspension completely replaced. I've had the dash out and most of the interior panels off and have it just about 100% rattle free. Down to these last couple of issues and I'm home free. Appreciate any and all help.

 

Lots of info on here about driveline angles.

https://www.cherokeeforum.com/search.php

 

Look at the proximity of the exhaust pipe to the relief in the trans mount cross member where the pipe crosses over the top. It's probably close to the left side of the relief in the cross member. It should be (basically) dead center on that relief to prevent the exhaust pipe from rattling against the cross member. It can be adjusted to dead center by loosening all mounts, taking the weight off of them with jacks on the pans of the engine and trans. Then, getting in a suitable position, use a pry bar to move the engine/trans in the direction that would place the exhaust pipe dead center in the relief of the cross trans cross member. You might also loosen the clamps on the exhaust system to give a bit more flex. It may take a couple attempts to get the alignment right. When I changed the trans and engine mounts I didn't take the alignment into consideration and blamed the rattling on a crappy trans mount when it was basically my fault (crappy thinking). That clearance between the exhaust pipe and the trans cross member relief is pretty close but once you get the alignment right tighten everything down and you should be good.

There's some wiggle room in the holes for the trans mount where it bolts to the trans with the 18mm bolts, but not much. If my attempt to align my drive line didn't get results I was going to open up those two holes as a Plan B and shift the position of the mount relative to the direction I needed to counter the rattling. But, I didn't need to do that.

 

What is NVH?

 

It's one of the standard TLAs.

Noise, Vibration, Harshness.

 

Is your XJ lifted ? and why is the brace welded in ? and is the brace the trans crossmember that the mount sits on ?

 

 

Thanks

 

It is not lifted and the weld I am referring to is part of some of the mounts that are out there. There is a brace that connects both half's of the mount presumably for safety if the rubber separates. The original design does not have it. I know that at some point in time it was regulated in that all mounts must have a devise that would component from launching if broken. Not sure on the timeline.

 

This is not the insulator that's on mine. may be because it is rear wheel drive however it looks like a better design. Wonder if it would work on a 4x4. At any rate I'll try playing around with it. Thanks

 

Yeah I agree with you. every time I move it, it changes. You may be right that it's a matter of finding the sweet spot.

 

What is a TLA?

 

Not sure, I would guess it's just another way of saying acronym

 

TLA is a Three Letter Acronym.

 

BFH, BMF etc.