Poly Differential Front Snubber Bushings-Problems?
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
ok... i did not see anyone forwarding this problem with poly and definitely aluminum.... VIBRATION!! Rubber will help dampen vibration, the others will not... Poly is good for a-arms and other handling bushings, other than that go rubber only. I have been working on vibration for about 2 years now and have it almost all solved..,. I have read for days and weeks about this and would never recommend poly for motor mounts trans mounts and rear-rend mounts... unless you like BUZZZZZ/// 
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
I've certainly heard this said before, and there is truth to it. BUT I think it varies widely depending on the manufacturer. The ES poly transmission mount I have is actually similar in hardness to the rubber one I pulled out (fitment is another issue). Likewise, I'm able to visibly deflect their poly T-arm bushings between my thumb and forefinger even though I've heard quite a few people say the poly bushings are all hard as rocks. Outdated information maybe? ES at least appears to be thinking about this.
But... Fitment.... is it bad? what problem exactly?
Last edited by pauldana; May 20, 2009 at 04:38 PM.
Tech Contributor
Joined: Aug 1999
Posts: 15,124
Likes: 3,927
From: Connecticut, USA
I've used the ES poly eng & Prothane poly trans for 5+ years on an automatic and 4 spd without any vibration issue. Those are the only places I use poly as well. I won't use the snubber or T/A poly's.
Yes the aluminum will last but a lot as to do with the environment. I can put 2 C3's next to each other within a few year window and one will have near perfect mounts and the other eroded. For a hard launching car those discs for the cross member do help, for a drag car maybe even the snubber but for a street car I would still use rubber. Personal choice, not a big deal in my book,most owners will not need them. 'nuff said on my part on this thread.
Yes the aluminum will last but a lot as to do with the environment. I can put 2 C3's next to each other within a few year window and one will have near perfect mounts and the other eroded. For a hard launching car those discs for the cross member do help, for a drag car maybe even the snubber but for a street car I would still use rubber. Personal choice, not a big deal in my book,most owners will not need them. 'nuff said on my part on this thread.
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Poly bushings will last longer. They're not attacked by moisture or petroleum distillates. They won't "rot" away. Poly bushings also don't need to be pressed or staked on so they're easier to install. That was a big selling point for a garage monkey like me.
But... Fitment.... is it bad? what problem exactly?
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
I've used the ES poly eng & Prothane poly trans for 5+ years on an automatic and 4 spd without any vibration issue. Those are the only places I use poly as well. I won't use the snubber or T/A poly's.
Yes the aluminum will last but a lot as to do with the environment. I can put 2 C3's next to each other within a few year window and one will have near perfect mounts and the other eroded. For a hard launching car those discs for the cross member do help, for a drag car maybe even the snubber but for a street car I would still use rubber. Personal choice, not a big deal in my book,most owners will not need them. 'nuff said on my part on this thread.
Yes the aluminum will last but a lot as to do with the environment. I can put 2 C3's next to each other within a few year window and one will have near perfect mounts and the other eroded. For a hard launching car those discs for the cross member do help, for a drag car maybe even the snubber but for a street car I would still use rubber. Personal choice, not a big deal in my book,most owners will not need them. 'nuff said on my part on this thread.
But I very much appreciate the many opinions that have been expressed.
Last edited by Paul L; May 20, 2009 at 08:32 PM.
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
OK, I wimped out and decided to proceed on the side of caution. I got the rubber version from Willcox for $16.00. Thanks Willcox!
Interesting when you compare the size and texture of each. The poly (on top) is rock hard. The rubber (on bottom) moves with some finger pressure although still pretty tough but is pliable. But look at the difference in the widths of the larger cushion! There is something happening here that I do not understand. Why is the poly so much thinner?
Interesting when you compare the size and texture of each. The poly (on top) is rock hard. The rubber (on bottom) moves with some finger pressure although still pretty tough but is pliable. But look at the difference in the widths of the larger cushion! There is something happening here that I do not understand. Why is the poly so much thinner?
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Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,352
From: Santa Ana CA
OK, I wimped out and decided to proceed on the side of caution. I got the rubber version from Willcox for $16.00. Thanks Willcox!
Interesting when you compare the size and texture of each. The poly (on top) is rock hard. The rubber (on bottom) moves with some finger pressure although still pretty tough but is pliable. But look at the difference in the widths of the larger cushion! There is something happening here that I do not understand. Why is the poly so much thinner?
Interesting when you compare the size and texture of each. The poly (on top) is rock hard. The rubber (on bottom) moves with some finger pressure although still pretty tough but is pliable. But look at the difference in the widths of the larger cushion! There is something happening here that I do not understand. Why is the poly so much thinner?
Le Mans Master
Joined: Apr 2001
Posts: 5,000
Likes: 1
From: Minneapolis, Mn USA
My rear end resto I did this last winter has poly on all three mounting points (1982 batwing) and rubber in the TA's and swaybar. I have absolutely no vibration or squeek issues from this set-up.
My trans has poly, but the motor mounts are rubber locking type that are drilled and bolted together (snug only). Really tightened up the motor movement, but it does still move around, its not a solid type set-up.
My front suspension has new rubber everywhere.
I figured if there was any moving-rotational bushing, rubber would be the choice so I didnt have to listen to squeeks. That would drive me nuts!!!
Install the poly and carry on......
My trans has poly, but the motor mounts are rubber locking type that are drilled and bolted together (snug only). Really tightened up the motor movement, but it does still move around, its not a solid type set-up.
My front suspension has new rubber everywhere.
I figured if there was any moving-rotational bushing, rubber would be the choice so I didnt have to listen to squeeks. That would drive me nuts!!!
Install the poly and carry on......
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 98
From: Ontario
My rear end resto I did this last winter has poly on all three mounting points (1982 batwing) and rubber in the TA's and swaybar. I have absolutely no vibration or squeek issues from this set-up.
My trans has poly, but the motor mounts are rubber locking type that are drilled and bolted together (snug only). Really tightened up the motor movement, but it does still move around, its not a solid type set-up.
My front suspension has new rubber everywhere.
I figured if there was any moving-rotational bushing, rubber would be the choice so I didnt have to listen to squeeks. That would drive me nuts!!!
Install the poly and carry on......
My trans has poly, but the motor mounts are rubber locking type that are drilled and bolted together (snug only). Really tightened up the motor movement, but it does still move around, its not a solid type set-up.
My front suspension has new rubber everywhere.
I figured if there was any moving-rotational bushing, rubber would be the choice so I didnt have to listen to squeeks. That would drive me nuts!!!
Install the poly and carry on......
