poly vs rubber
Thread Starter
Drifting
Joined: Jul 2007
Posts: 1,671
Likes: 10
From: california
poly vs rubber
hi, i am just starting body off frame rebuild (64 coupe) the car is not stock and this is not a restoration. what are the advantages, disadvantages of poly bushings vs rubber bushings for suspension?? for body mounts?? im just starting to assemble the giant pile of misc. parts i will need for a complete chassis rebuild. thanks
Pro
Joined: Jan 2007
Posts: 524
Likes: 12
From: Auckland New Zealand
hi, i am just starting body off frame rebuild (64 coupe) the car is not stock and this is not a restoration. what are the advantages, disadvantages of poly bushings vs rubber bushings for suspension?? for body mounts?? im just starting to assemble the giant pile of misc. parts i will need for a complete chassis rebuild. thanks
As for body mounts - stick with rubber. They are not particularly stressed and the originals lasted for 40 yrs.
Cheers
Neville
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Rubber only lasts 30 years if it's extremely coddled and you're lucky. The rubber bushings on my 2000 Cherokee are already decaying.
Melting Slicks
Joined: May 2007
Posts: 3,461
Likes: 18
From: cooper city florida
I had my 65 aligned and i mentioned that I was going to replace the front springs and buy a complete poly front end rebuild kit. The shop owner and the mechanic both told me that I would be better off staying with rubber. He did say if I had to use poly,use it on the sway bar bushings. Since I drive less than 2k miles a year,only in good weather,and the fact my vette is garage kept,I figured the rubber should last at least 20 years...... I went with the rubber.
Burning Brakes
Joined: Jun 2004
Posts: 1,123
Likes: 2
From: Sandia Park NM
I installed poly graphite bushings and have no squeaks what so ever.
I installed them in front suspension, trailing arms, etc, except the body mounts, which I replaced with rubber mounts.
I've had other C2 owners drive the car, and everyone has commented how well it handles, and how quite it is.
In addition I used a product called dum-dum, its a clay like product that is tacky. I used it throughout the entire interior. As example where the dash attaches to the body, where the cluster attached to the dash, glove box to the dash, another words any where I thought a squeak might come from I used the material. So far no squeaks.
No complaints in this area of the rebuild.
Dennis
I installed them in front suspension, trailing arms, etc, except the body mounts, which I replaced with rubber mounts.
I've had other C2 owners drive the car, and everyone has commented how well it handles, and how quite it is.
In addition I used a product called dum-dum, its a clay like product that is tacky. I used it throughout the entire interior. As example where the dash attaches to the body, where the cluster attached to the dash, glove box to the dash, another words any where I thought a squeak might come from I used the material. So far no squeaks.
No complaints in this area of the rebuild.
Dennis
Last edited by OCS1667; Oct 9, 2007 at 01:57 AM. Reason: spelling
Le Mans Master
Joined: Jan 2002
Posts: 8,913
Likes: 283
Poly bushes will transmit a bit more road vibration, noise, thumps etc, but will tighten up suspension under hard braking or sharp direction changes. I tend to put poly bushes in joints that do alot of hard work, eg lower rear struts, sway bar etc.
As for body mounts - stick with rubber. They are not particularly stressed and the originals lasted for 40 yrs.
Cheers
Neville
As for body mounts - stick with rubber. They are not particularly stressed and the originals lasted for 40 yrs.
Cheers
Neville
I have poly on the sway bar bushings, link ends and the rear spring link pads.
Le Mans Master
Joined: Jan 2002
Posts: 8,913
Likes: 283
Poly only squeaks if it's old (materials technology has moved on) and/or not greased properly. As an example, I had the same set of poly suspension bushings in two different Eagle Talons over the course of a decade and never heard one tiny squeak. Same goes for the front sway bar bushings on my 77.
Rubber only lasts 30 years if it's extremely coddled and you're lucky. The rubber bushings on my 2000 Cherokee are already decaying.
Rubber only lasts 30 years if it's extremely coddled and you're lucky. The rubber bushings on my 2000 Cherokee are already decaying.
I think most of our cars live in heated garages, no rain or "drive through" car washes and we diligently wipe extra grease and oil away.
Mark
Last edited by ghostrider20; Oct 11, 2007 at 02:51 PM.
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Melting Slicks
Joined: Dec 2005
Posts: 2,576
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From: Sarasota Florida
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Melting Slicks
Joined: Sep 2003
Posts: 3,050
Likes: 2
From: Orange Ct
Are you comparing old, worn out rubber to new poly? Given that the defection of the poly parts may be less than rubber, deflection of the frame would be orders of magnitude larger. The stiffer joints may transmit road feel better but as for improved handling.I don't know the answer, are there any A B tests on the track or skid pad?
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Are you comparing old, worn out rubber to new poly? Given that the defection of the poly parts may be less than rubber, deflection of the frame would be orders of magnitude larger. The stiffer joints may transmit road feel better but as for improved handling.I don't know the answer, are there any A B tests on the track or skid pad?
Intermediate
Joined: Mar 2005
Posts: 43
Likes: 0
From: Powell Ohio
Sometime back (try a search) someone mentioned advantages of both, primarily, he was recommending one for cruising and the other for touring?? It was an informative post that made a great deal of sense.
Tech Contributor
Joined: Aug 1999
Posts: 15,124
Likes: 3,927
From: Connecticut, USA
I use poly eng and tranny mounts. Rubber everywhere else. I've found some poly parts were not the correct dimension and were either under or over size. Diff mounts and tranny mounts were some of them.
Melting Slicks
Joined: Nov 2004
Posts: 2,302
Likes: 26
From: Cave Creek AZ
When I did my body-off project last winter, I did the same. I am pleased with the handling and ride, plus there are no squeaks.Roy
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
Tech Contributor
Joined: Aug 1999
Posts: 15,124
Likes: 3,927
From: Connecticut, USA
[QUOTE=I'm Batman;1562262522]I think I figured out the issue with ES's transmission mount - it seems to fit fine without the exhaust support plate. Was Corvette unique in using that bracket?
That particular tranny mount was 1/4" off. I contacted their engineering dept 3 years ago about it. I was told the mount would not fit corvette yet they never changed any of the catalog references to reflect that, - at least the last time I checked. Even purchased a eng and tranny kit from Summit about 2 years ago and still had the wrong tranny mount in it.
I found Prothane makes/made a poly tranny mount that was very close to the rubber size. It works.
I only switched to them on the engine mounts to eliminate the common rubber mount shearing. The poly Diff mounts were off enough to cause the banging associated with worn out rubber mounts. Not sure if all suppliers on these have the same problem?
That particular tranny mount was 1/4" off. I contacted their engineering dept 3 years ago about it. I was told the mount would not fit corvette yet they never changed any of the catalog references to reflect that, - at least the last time I checked. Even purchased a eng and tranny kit from Summit about 2 years ago and still had the wrong tranny mount in it.
I found Prothane makes/made a poly tranny mount that was very close to the rubber size. It works.
I only switched to them on the engine mounts to eliminate the common rubber mount shearing. The poly Diff mounts were off enough to cause the banging associated with worn out rubber mounts. Not sure if all suppliers on these have the same problem?
Race Director
Joined: Jul 2005
Posts: 13,685
Likes: 61
I'm very pleased with polygraphite in my 422,000-mile 1990 Suburban. The handling is firmed up and stays like new.
Had the same good experience years ago after replacing the rubber in my wife's XJ6 Jag steering rack.
No noises in either case.
Had the same good experience years ago after replacing the rubber in my wife's XJ6 Jag steering rack.
No noises in either case.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
[QUOTE=GTR1999;1562262662]
I picked up an E/S C3 kit from eBay - the mount in it was only a small bit taller than the original rubber piece - the difference was about the same thickness as the exhaust bracket, which is a pretty danged thick piece of metal. I'll check it again if it gives me any trouble.
That particular tranny mount was 1/4" off. I contacted their engineering dept 3 years ago about it. I was told the mount would not fit corvette yet they never changed any of the catalog references to reflect that, - at least the last time I checked. Even purchased a eng and tranny kit from Summit about 2 years ago and still had the wrong tranny mount in it.