Transmission Mounts: OEM Rubber or Polyurethane

[outrun]

Okay,

I have done some reading on Polyurethane being quite squeeky and stiff when used as suspension bushings.

What is the consensus here on using Polyurethane versus OEM Rubber Trans Mounts? Will the Poly be squeeky or noisy? Or in this location it is irrelevant. I like soft and quiet personally.

This is for an Camaro/Firebird with a 4L60E Trans. One aftermarket Poly Mount kit I saw included hardware and said it had a unique safety keeping the metal together in case of separation.

 

[Colt45ws]

It will not be squeeky, but it will transmit more vibrations from the drivetrain to the car.

 

[another Todd]

Ditto!

 

[mechtech2]

Poly in transmission or engine mounts make vibration much more noticeable. They can help a lot with the shifting of a manual trans or transaxle. Wheel hop in a transaxle equipped car will be helped a lot.
For a rear drive auto transmission, I don't see any benefit for the street.
Many poly suspension components have grease fitting, or sipes for grease inside, or are of a graphite material. They sure can squeak, and is a very real problem. Synthetic wheel bearing grease works very well. Some other greases will attack the poly.

 

[johnd]

I saw a post on a Camaro board where a guy said, "if you put in a poly transmission mount, don't count on listening to your radio while going down the road."

 

[televascular]

A poly bushing WILL squeak like a #@$%! if not lubed regularly. Many autocrossers consider this a small trade-off for improved road feel and handling response. It does transmit more noise and vibration... I don't recommend it for a daily driver unless you're really pushing your car.

If it's available for your model, you should try to find nylon bushings. They need no lubrication, but are significantly more expensive than poly's.

 

[mechtech2]

I think that you mean Delrin, not Nylon.

 

[NYEngineer]

I ran a poly mount in a 80 Trans Am that I swapped a TH700R4 into behind a Chevy small block. The whole car had poly bushings throughout... The subframe bushings, suspension, sway bars... It had 50 series Comp TA's and felt nice and tight. I did have to lube the bushings with the proper "grease" and they were a little harsh, but it was a performance car. I added dura mat to the interior and it helped quite a bit. If you need strength, you won't mind the poly mount. If it's a car you take your grandmother to church in, go with rubber.