Dear J-body enthusiasts,

For the past two months, I was having some issues with my 04 Cavalier - there was a scratching/squeaking noise emanating from the transmission area. These noises were most prominent during initial takeoff in forward/reverse. In addition, the gear engagement of my 5-speed was becoming progressively sloppier. In an attempt to diagnose this problem, I decided to check the torque on the bolts to my transmission mounts. Approximately 8000 miles ago, I had installed the polyurethane transmission mounts.

Upon further inspection, I found that all of the bolts were tight, yet the transmission was "sagging" in both of the front and rear mounts. When I removed the mounts, I found that the center of each mount was wallowed into an oval shape, and thus the steel bushings in both of the mounts were moving up/down 1/4" vertically. Once again, these mounts have been in this vehicle for approximately 8000 miles.

I tried the poly engine mounts - the additional shock transmission/vibration from these mounts was intolerable, and thus I got rid of them. I liked the poly mounts (crisper shifting, etc), but the additional vibration and the eventual failure of the mounts has put a bad taste in my mouth. Aside from the poly suspension bushings (which I have, and they are working well), I now believe that the "cost" (vibration, failures, etc) of the poly engine and transmission mounts far outweighs their benefits.

In conclusion, I went on GMpartsdirect.com and ordered a new set of original mounts. In any case, the additional vibration caused by the poly mounts was getting old - I'll be looking forward to reinstalling the originals.

I'll be telling everyone I know to steer clear of the poly trans mounts.

Sincerely,
illtmprdman

you know that you have to lubricate ANY polyurethane bushing? If you don't lubricate them, it will squeek and it will get worn.



Gilles
2.3 Ho

When I installed the bushings, I used gratuitous amounts of silicone grease.

i've had my poly tranmission mounts in for about 100000km (~63000miles) and they are still as firm as day one. maybe you just got some bad ones.

Didn't even know they made poly tranny mounts for the Eco......


N2O + Bolt-ons = 220Hp/250Tq

Coming Soon:HpTunersPro, EagleConnectingRods, WiescoPistons, 13sec2200

I noticed the same thing with my poly mounts.I had a squeeling noise coming from my transmission when i took off,but it turns out it was my clutch.But when i checked the bolts for the trany mounts,i noticed the holes in the center of the mounts were streched out.Ive had the mounts in the car for less than a year.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

Interesting...guess I'll be taking a look at mine in the morning!




Eh...old man with a Corvette now...it was bound to happen sooner rather than later right?

I was under the impression that using poly trans mounts without the engine mounts would be a bad idea.... I can't remember who told me that... but it looks like they were right!

BTW.... all manual transmissions use the same trans mount bushings.... 95-05... Isuzu or Getrag. Big ol' rubber thing.

Mine were good but like Lenko said...I have the motor mounts as well so maybe that's why? I was worried!!


Eh...old man with a Corvette now...it was bound to happen sooner rather than later right?

I think you just got a bad set. I have both motor mounts and they are 5-6 years old no problems. Also they are worth the money I spent.



FU Tuning

think about it. one side of your engine is moving freely back and forth and the other side isnt. of course that stiff side that is going to wear out.


i will look at mine after 4k miles on it. but i am not worried.

i had some mark pain tranny mounts( a guy here made them) and them came apart. IT was two peices of poly unlike the prothane's ONE.

i just put some prothane ones in there.

The problem with the Prothane bushings may be that the bolt hole is exactly in the middle of the bushing whereas it is off centre in the stock bushings. With it being in the centre, the tranny is trying to force the bolts in to the natural position.

Mark P.

My prothane ones lined right up. No tugging on anything to get the bolts in, they slid right in.

Install took more effort than I thought. First I failed to notice the steel tabs on the stock ones and had the rubber bushings stretched about 4 inches out of the mount using a press before I noticed The front tranny mount is a right pain in the ass to get at. I had half the damn front end apart before I could get the bolt out.

I did the engine mounts first though, and noticed a big difference in vibration. Adding the tranny mounts didn't seem to add any more vibration, although it did firm up the shifts.

mine is definately rounded out. looks like its time to make a nasty call to prothane and then create a few solid plates for the mounts. its just the trans...how bad could a solid trans mount be

anyone got a solution?



I used to race cars, now I race myself.
5K PB: 24:50
10K PB: 54:26

i will have to get in there and look at my mounts.

But i will be pissed if i have to take them apart again. argghhh.