Carabinerx

So I’m trying to replace my worn motor mounts, everything is loose and came free except I can’t for the life of me get the main through bolt out enough to remove the old mount! This is the driver side and only one I’ve done so far. I haven’t exposed the threads yet, those are just grooves from spinning it/trying to vice grip it out.

any tips or tricks? There’s no where to pry on in here, I’ve tried going up and down on the jack trying to find a sweet spot but I’m afraid of going too high and damaging something else.

aroundincircles

Looks like you have a jack under the engine? I would slowly move it up and down till those holes line up to just pull it out. That's what I did. the other option is if you have a powered socket wrench, put in on there to power loosen with a boxed wrench on the other side of the head pushing on it to pull it out. (if that makes sense at all).

fb97xj1

Motor mount itself probably shifted just enough with it being loosened from the frame, to catch the bolt. Put the nut and bolt for the frame back in and try the again.

Carabinerx

Thanks guys, I did wind up getting them both replaced, had to get a friend to work the jack while I worked the bolt.

problem is now that I’ve changed these and the trans mount, something is still rubbing somewhere when I take off from a stop or turn right — all started after I changed the tansmount. It’s gotten milder but I suspect something shifted while changing the trans mount and it feels internal, like the tcase or the transmission itself, something is rubbing, you can feel it increase as you increase speed, but just goes away after 10mph, but almost always happens when turning right.

does anyone have ANY ideas of what could be going on?? At highway speed I could smell some burning smell, rubber-like, maybe clutch smell? I don’t know enough about these things to diagnose it

boxburn

Take a good look around underneath for any signs of rubbing. The smell is a strange one though.

Carabinerx

Thanks boxburn ive done so, extensively, and had someone drive while I walked beside, and I can't see or hear anything-- which is why I believe it must be internal, because you can only feel it from within the car through the floor. I once read the clutch or something in the tcase could be not fully...not seated, but engaged? The push or pull rods that actuate things might not be fully engaged or some such thing. I know nothing about the tcase or what is happening internally.

boxburn

I wouldn't have thought a mis-aligned tcase linkage would cause the sort of noises you describe, especially if it goes away at a higher speed. However I don't have much experience with them so could be wrong.

awg

it is slightly possible you have a weird issue, but to test, you should be able to change ranges better after a mount swap, so go and put it thu its paces

That should solve or identify any potential issue there

When I do a mount swap, I will do things up, but not super tight, before i run the engine, then torque them down fully, its tricky though, cause the motor does want to rotate within the engine bay when running

Griffyorcono

I have had this problem and so I am going to introduce you to the list of things I did to fix it and give you as much info as possible.

Under any sort of acceleration I would hear the noise you speak of, it sounds like a flywheel grinding against something. So I started there and check the flywheel, it was fine. But there is actually a ton of issues this could be

One is axle wrap. My very unscientific idea was that because the new mounts were more sturdy better power was transferred to the rear axle and the transfer case had less give. So the axle was wrapping and messing up the pinion angle causing the grinding noise at the t-case.
If your an auto trans your flexplate could be bad and grinding into something within the bell housing. If you're manual trans your flywheel could be moving because of loose bolts or bad crankshaft bearings (this is rare do not get stressed out).

Because you replaced your mounts it could've moved everything around a bit and caused the 4wd switch lever to be out of alignment which would mean your transfer case is barely in gear so it is grinding teeth.

Lastly, check all the joints in your drivetrain to make sure everything has no play and is working smoothly. If you cannot follow these sorts of instructions or cannot wrap your head around the things I'm explaining to you, you need to bring your Jeep to a qualified mechanic so you don't make something worse.


My final answer to your problem though is going to be very convoluted. Though I had the same problem that you have my issue was a weird one. What fixed my problem was new motor mounts and making sure they were adjusted properly so the motor was straight in the engine bay and not twisting uncontrollably.

Carabinerx

@Griffyorcono Thank you for all this, ill take a look at the list you mentioned, I will say this, in the driveshaft going to the rear wheels theres a little play, it seems like the ujoint there may be a little loose -- not much though, I'm not sure if any is appropriate or a little is to be expected, but also the whole thing can rotate back and forth some. Its just weird that it didn't have this issue before changing the mount, which is why I'm concerned its something in the tcase. Putting it in 4wd doesn't make any differences. The weird thing that I believe is some kind of clue, is that it happens when I turn right (and of course taking off from a stop, but not always or as consistently as the right turn).

Ill take a look at the linkages down there, if something isn't fully engaged. But also consider it would happen with the wheel turned right and not moving, but only if in gear, disappears when in park...any clues from that?

aroundincircles

There should be 0 play in a ujoint if there is play, it has gone bad and needs to be replaced.

Do you have somebody who can stand outside of the vehicle as you reproduce the sound to more closely locate where it is coming from?

Carabinerx

Damn, ok well that might be the cause then with the possibly new angle of the transmission. Doesn't explain the burning smell, unless that was just the coating on the transmission rubber (how hot does that really get?). Ive replaced ujoints on the front axle shaft, is it much more challenging to do the drive shaft? I have walked beside it while someone drove but I couldn't hear it or identify it, its mostly felt through the floor. But maybe I can get someone to do it again and focus on the drive shaft -- its hard for other people to notice for some reason (they own more modern cars, haha) so I can't get reliable info.

Carabinerx

Well I’ve seemed to figure it out! Not exactly sure what’s going on but it’s where the bottom of the trans mount is meeting that cross bar that one section is not seated dead flat — maybe a bit of crud is not allowing to lye flush all around, don’t know I can’t see any gaps, but that’s where the vibration is coming from, it’s rattling against that cross bar.

hopefully a cleaning and a tightening of the four bolts attaching the cross bar to the mount will seat things nicely. Either way not as severe a problem as I thought.

Idunno

What's rattling on the cross brace? The trans mount or the exhaust pipe? Changed mine in the last couple weeks and noticed the main source of vibration was contact with the exhaust pipe on the trans mount brace. I initially loosened the clamps at the cat, raised the cat up with a jack and tightened the clamps. It appeared to be clear but still contacted during operation. The problem was a combination of new left motor mount and sagging tailpipe hanger. Changing the left motor mount re-clocks the engine slightly clockwise because you're raising it up somewhere around an inch from where it was with the old compressed mount. This causes the right side to rotate downward and bring the exhaust pipe closer to the trans cross brace. If your tail pipe hanger was stretched like mine was then the gap between the exhaust pipe and the trans cross brace could be closed down if they aren't already touching. If they aren't touching but are close, accelerating the engine will cause it to torque in that direction and make it contact the trans cross brace. I fixed my problem by placing a hose clamp around the rubber tail pipe hanger and tightening it up enough to raise the exhaust pipe clear of the trans cross brace.

The burning smell could be old grease or fluid from the trans cross brace cooking off on the exhaust pipe.

Carabinerx

interesting, thanks for that, I checked underneath while it was running and making the vibration, it didn't seem like it was the exhaust (which I was hoping for). I could grab the base of the mount where it meets the crossbar and pull/apply pressure and it would stop. It genuinely just seems like this new mount is a hair shorter than the original and buzzes slightly against the cross bar, even though everything is tightened down. The mount is tight and solid to the transmission itself, and feels so at the crossbar too, but like I said if I put enough pressure there it would stop, so until I can replace it I'm honestly (and this is a bad idea to some degree but I don't think really that damaging to anything short term) going to see if I can just wedge some super thin material in there to stop it. Once under weight while driving its fine, it settles in, its at start up and turning at low speed that it flexes and allows probably one side to lift just enough to buzz.

This is all speculation, once it stops raining for the 3rd day in a row ill take a look and see whats really going on.