Gtpguy

My car has whats in the sig and has 190k on the body. I've owned 8 or 9 Fbodies since 1996 so I know my way around them. I've replaced tranny mounts on each of my firebirds once and never had another one go out. I've always used Autozone trans mounts. But this car is eating them like crazy. This last one was a doorman from Napa, the 4 before were auto zone anchor POSs.

Is there a reason why they could keep breaking? This last was installed last saturday and just tonight broke on me. Not even 4 days did it last. Could a worn/old torque arm mount or something like that cause them to break so frequently or is it just as simple as the quality has really gone down hill in aftermarket trans mounts?

And yes, Im going with a poly mount this time.

mrmint69

Has to be something broken, installed incorrectly or worn out thats causing the issue.

Gtpguy

Yeah, been reading that its most likely bad motor mounts that cause trans mounts to go bad. I ordered the prothane just because Im sick of the bowling ball THUD every time it shifts. Im hoping I'll be in the group that doesn't notice too bad of a buzz/vibration.

smartinz26

I got the poly prothane one from the parts store. tight as a drum. i think it was only $28 or so...

Ultra_Z

i have polys on both my lsx cars... 20k plus miles and still good!

Dtimekw

+1 on motor mounts.

Injuneer

No substitute for the Energy Suspension polyurethane mount. For some reason, ES advises they do not fit the 4th Gen cars. But based on my experience they do. Maybe it has to do with the height difference that Rob/Shoebox pointed out:

http://shbox.com/1/trans_mount.jpg

I've had the same ES poly mount under 3 different setups on my car (stock T56, TH400, TH400 + Gear Vendors) and it's still healthy. And that's with 800HP/800 lb-ft.

If you are still running the stock torque arm, mounted in the stock location on the tailshaft of the tranny, it's contributing to the failures, because every time you accelerate, the TA is trying to lift the trans off the mount. There is also a possibility that you have the pinion angle messed up, and you are getting some weird reactions in the driveshaft.

Seems like most A4 owners are unhappy with the noise and vibration transmitted by a poly mount. Does not seem to be as big an issue with M6 owners.

sbca96

This.

It was basically unbearable on my 1993 Camaro Z28 and was removed the next
weekend. Sitting and idling it made the car feel like a paint shaker. On the road
the rear suspension translated a ton of input I didnt want.

The engine had close to 200k on it and seemed to idle smooth, but with poly it
amplified it to the point you would have thought two cylinders were missing!

I ended up using the mount on the LT1 install into the '78 Camaro, works fine.

Tom

Gtpguy

The torque arm mount is shot and I asked about it on other boards and no ome thought it would help cause trans mounts to go bad. I dont want a poly mount, I want a new oem tq arm mount to see if im right. As for now the car is 1500 miles away in storage but I threw in the rubber mount with 4 big band clamps around it. Haha id rather have it smooth.

sbca96

I guess if the mount that receives the torque arm at the rear of the trans had a
lot of slop in it, the arm could "pick up speed" and yank the trans mount with an
increased force causing it to break easier .... sounds possible at least ...

Tom

bluz28

ES has 2 trans mounts for the 1982-2002 camaro/firebird, 3-1142G, and 3-1158G. There both use softer a urethane than the 3-1108G which has the larger preload bumps, also the 3-1158 is .4" shorter than the other 2 mounts.