Heard that poly ones are supposed to be better than rubber but also heard they cause more vibrations. So which is better??
here's a pic of the soon to be taking a much needed vacation old tranny mount

 

poly is bullet proof rubber isn't

 

I'm sure but I don't see the need for bulletproof mounts, do you?
Are poly and rubber the only options or are ther others?

 

Pretty much only options. Get a poly and likely never replace it again. Or get the rubber and likely replace it again. The extra vibration is negligible IMO

 

Rubber-Can tear the first time you put the tranny in get and give it some snot

Polly-Will pretty much never fail. vibration is minimal

Aluminum-Will never break, but if you think vibrations with a Poly is bad, this will be insane.


Poly is by far the best choice. and with the poly being about the same price as a rubber, its a no brainer, why pay to replace it when you shouldnt have to.

 

I have used the poly mounts and I had problems with the bolts stripping out. They would only last me a few weeks. Now I run rubber and its lasted for 2 months with no problems

 

I just replaced both tranny mount (shot) and torque arm bushing ( a case of while I was in there) with the poly style. The car never ran smoother.
1982 Trans Am, Stock 305H with a 200C

BEWARE: Soak the tranny front crossmember bolts and don't use
an impact or you'll be cussing and drilling like I did. The
front driver side bolt is close enough to a rail opening
to get rusted - I found out the hard way after my Son
snapped it off with the impact gun.

Good luck,
Joe

 

Vote one big yes for Poly here, the rubber ones blow! I have Poly motor mounts and tranny mount, a little more vibration but that is mainly do to the motor mounts, but still not very bad.

Kevin

 

okay... guess it's poly then
just wondering what is poly anyway?

 

I've never had vibrations with my poly mount. Poly? Well its made of something lol

 

polyurethane

 

Thought polyurethane was just something that was used to seal up deadspace between windowframes and walls in houses The consistency of the mount must be VERY different, perhaps there's some other components in there as well. Seems to be used for alot of stuff this. Understand it even is in some paint.

 

yeah i almost replaced my trans mount with a poly one...but i ended up returning it cause i really needed da 30 bucks....rubber ones will always break on you and it sucks i hate hearin a big thump when i floor it......soon i'll replace it once and for all.....but i heard that to leave da spacer out to get less vibration...so does anybody know if this is true

 

Sources and brands for the poly mount??

 

yeah mine shakes pretty bad now. But as u can see it's not in the best of shapes.
Cool avatar rudyt5000!

 

http://www.jegs.com/cgi-bin/ncommerc...80&prmenbr=361

also this is a common thing, when installing the new mount you have to widen the hole on your crossmember a bit to fit the new bolt in.

 

Maro,

So it will be Jeggs # 355-3-1108G GM transmission mount black
$22.99?

 

yep, or if ya want it red in color instead of black, 355-3-1108R, both are the same material, so it really is preferance.

 

Thanks,
I will order it just in case..!!

 

i was wondering....there are 3 holes on the poly one....but on a new rubber original it has a bolt in da middle molded in? so do we have to re-use this screw or something ? or have to buy a new bolt and screw it in the poly one ......oh just got my avatar bout a week ago thanks for noticing it ...lemme guess its similar with yours huh

 

kinda similar yes big terminator fan?
Good question about the bolt in the middle... was wondering about that...

 

When I did mine on the IROC I went with the OEM grade rubber one. It was like $3 or something. *shrug*

 

there are three bolts holes in the bottom because it is a universal mount, some cars had mounts that used the two outer ones, the Fbody uses just themiddle one. it comes with new bolts for bolting the mount to the xmember, reuse the bolts that go into the tranny tho.

 

My motor mounts are Prothane and i got them from Spohn, and my tranmission mounts are Energy Suspension and I get it at Pep Boys.

Kevin

 

Hey Kevin,
Do you have part #'s?

 

For the Motor mounts http://www.spohn.net/product.cfm?productid=1363 . The trany mount was just from Pep Boys. I think it was $15 - $20.

Kevin

 

Thanks!

 

I bought the poly mount a while back when I was running the stock 700R4, and I immediately removed it right afer the initial installatoin. The massive vibration was totally unacceptable. It made the floor vibrate, the shifter/console roar, and was LOUD. Outside of sway bar endlinks this is my only experience with poly.

I just completed the T5 swap this weekend, and decided to give the poly mount one more try. Needless to say, its gonna get taken out again. Yes it keeps your driveline and torque arm more stable, but the vibration is out of control.

My $0.02.

 

i think you got other problems, i have no more vibrations than what i had with the stocker.

 

well i just replaced mine with a poly one...and damn its worth every penny....now i will never worry bout changing it again with a rubber one....but i had to reuse all the bolts from the old one cause they were different thread size...and i kept that spacer off cause i heard with it you get alot of vibrations....and i guess its true not a single vibration with my car

 

Replaced mine with a poly, left the spacer and no vibrations. Some people are just too damn picky.

 

I bought the poly mount a while back when I was running the stock 700R4, and I immediately removed it right afer the initial installatoin. The massive vibration was totally unacceptable. It made the floor vibrate, the shifter/console roar, and was LOUD. Outside of sway bar endlinks this is my only experience with poly.

i had the exact same problem. put in an energy suspension (yes it was the right one) tranny mount, got HUGE amounts of vibration. not a case of someone being picky, the entire car would shake and rattle when i'd rev the engine, even in park. my best guess is it raised the transmission too much. took it out, put in a new stock mount, nice and smooth. havent tried it without the spacer but planning on it when i stop slacking.

 

This is a little off thread, but....
Yep -- I think yer right. I just spent most of the night jacking around with my driveshaft trying to get the vibrations down. With the T5, the vibrations are crazy even after swapping back to the stocker tranny mount. So I concluded that its not the mount. Perhaps the driveshaft? With almost 300K miles, I'm sure its wasted. So I removed old stock ujoints by melting the plastic retainer shizzle, installed new Ujoints, but still vibrates. The stock joints didn't really look that bad, though. Next I tried to isolate the vibe -- removed shaft, and ran the engine on the stands without it, and no vibes. Removed wheels, ran on the stands without them, still vibrates! Pinion has no play, so next I started messing around with pinion angle, 180 pinion swap, etc.... Nothing worked. Gonna get the shaft balanced (just for now)to suffice until I buy an Aluminum LS1 (sooner than later!) Next: 10 bolt rebuild.

Anyway, thanks for callin me out. I'm sure once the shaft gets smoothed out, I'll put the ES trans mount back in.

 

i just put one of these tranny mounts in my car and it says that the plate is not a spacer its a preload plate and not to leave it out. is there any truth to this

 

so those universal mounts work on our cars??????

well i actually just replaced my mount with another $4 rubber one but will definately have to pick up a poly one for next time....thanks for the tip guys!

should i leave the metal plate on or take it off???

 

Removing the metal plate makes the height difference between the two mounts less of an issue, thereby maintaining the proper driveline geometry while still being able to use the stiffer poly mount.

I ran my mount both with and without the plate, trying to solve my vibration issues. The mount still looks brand new and IMO wasnt affected by removing the plate. If you have 500 hp and run slicks maybe the plate is necessary, but I'd say you'd be OK to run it without. If the added height of the plate doesn't upset your driveline angles, why take it out?

 

i left the plate in, and the one i got works, had three holes on the bottom, only used one, but had to wide the hole in the cross member a bit so the bolt fit through. nothing major.

 

i stand corrected. the first time i installed it, i didnt widen the crossmember hole and had the mount sitting off center. it still baffles me as to why, but when it was installed like that it still clunked like it did with my old, torn mount. put it back in earlier, with the load plate, theres a bit more vibration but i can live with it. and man what a difference from having to baby it off the line and through every shift, i've been having a blast

 

Mine stripped out on me too. I just haven't tapped it out yet again to try again. I put the old "new" rubber one back in two months ago and just kind forgot, another thing to do.