Hi all,

have a 89 5.7 IROC....It's pretty much a daily driver (I don't take it down strips or do anything crazy in the street) and i hear much back and forth about poly is superior to rubber (generally speaking.....regarding tranny mounts, for my purposes, would a plain ol' rubber mount do me fine or is it really worth getting the poly (or some other material)? Is the extra vibration
a significant amount? And wouldn't that cause premature wear of other parts throughout the car?
Whether rubber or poly is your preference, please recommend me a specific brand/p-n because I don't know enough and there are too many for me to make a choice on the net!

Thanks a lot,

Barry

 

a poly bushing wont create any large amounts of vibration/noise, though you may pickup a little, it all depends on the car.

Im currently using Prothane, i had one from energy suspension and destroyed it in less that 5k miles, maybe even less i dont remember exactly

 

Though I have poly pretty much throughout (Energy Suspension, which is available from Spohn, a board sponsor), for a DD, I'd recommended OE rubber. There is some vibration with poly (so much so that I swapped out the poly secondary trans mounts for rubber. There is, however, significantly more poly involved with those particular mounts). No premature wear on other parts.

JamesC

 

I got the ES poly mount from autozone, its the same part # as summit, spohn, whatever sells.

I really didint notice any differece, except the fact that my shifter sits about 1/2 higher than with the rubber mount. I remember I was surprised when I actually had to raise the floor jack to lift the tranny so I could fit the new mount in. My stock one wasnt even that bad, just was starting to get dry rot so I replaced it before it broke.

If you are trying to use it for any performance gain, its not worth it on a DD / near stock car. It doesent transmit any extra vibration though, and the shifter still swings when I rev the motor. And you might have to use a dremel to open the hole in the factory crossmember.

 

I broke 3 stock rubber mounts and finally got the prothane.

 

There is hardly any rubber on my car anymore. I have poly everywhere. And my motor isnt exactly "smooth"... But I DD it and think its just fine. No bad vibes, parts dont wear out, and it feels alittle snappier. Some people say it doesnt affect performance, but I feel like energy gets wasted if the motor can torque too much to the side during acceleration. It just feels more responsive. I got the same result when I put poly mounts in my lifted Jeep.

Could be different on different cars though. Just like someone else mentioned... Each car will react alittle different.

J.

 

Thanks for the input guys....

so I was impatient in putting in an order and got a bootleg *** mount "made in India" from a local "performance parts" store....hopefully the weather will permit. Someone tell me the ideal jack/mounting points to perform this task without getting crushed or putting too much twist on the frame? I've been reading a lot of complaints about rubber ones sucking and not holding up......but I'm pretty sure the one thats in there now is original (at least hasn't been changed in a lonnnng time) and the car's got 120K, so we'll see how well "Advance" from India holds up.
Thanks again

 

I put mine in with the car on ramps LOL.

Just use a floor jack to hold up the rear of the tranny when you take the mount out.

I couldnt get the bolts loose with a ratchet, so I had to remove the crossmember first, and then get the impact on the tranny mount bolts.