Poly Differential Front Snubber Bushings-Problems?
Tech Contributor
Joined: Aug 1999
Posts: 15,177
Likes: 3,995
From: Connecticut, USA
Tech Contributor
Joined: Aug 1999
Posts: 15,177
Likes: 3,995
From: Connecticut, USA
Ok! I’ll probably fire the whole lot of you up with this one! I’m putting on my bullet shield right now, strapping in and oh. .. I’m painting a target on my back too!
I’ll start with Norm: Way back when Lassie was a pup, we installed poly on Norm’s car! Countless times of putting grease on the poly sway bar bushings did not stop the squeaks. Finally we just replace the entire poly for the standard parts and no squeaks, no grease!
On my own personal car years ago I installed Poly! Same issues and one A-Arm shot! Yes I was hard on this car too so I’m sure this added to the problems.
It has always been my “Personal Belief” (and you have to realize that Poly has been around a long long time.) that poly should only be run on cars that are going to be raced around pylons, road raced and or for someone wanting to just run the car hard on a back hills road. Every where poly is installed in a car tightens up the car and I agree that this is a good thing if handling is what you want. If I were racing a car there is no way I would use anything else.
However, it is also my thought that everywhere you replace a part that was designed to have give and movement you also sacrifice ride! A good example of this is the front A arm bushings! The bushing was designed to have movement and not be hard and fixed; something has to suffer from changing them out.
If I remember correctly on some vendor sites there are notes about the poly bushings being used for the snubber cushion? I have seen the rear end on a performance car actually damage the frame bracket from having a poly busing installed in the car. (on a stock car I doubt you could damage this bracket with poly). If this bushing was designed to be solid I would thing GM would have just bolted the rear end front bracket straight to the frame.
You also have to remember that I was raised in a Chevy dealership! I’m not GM brainwashed, but sometimes I think making a better mouse trap can be a down fall. Most of us are driving the cars to enjoy them and lets face it the cars do ride hard enough on their own. Maybe I’ve brainwashed myself and my employee’s and maybe I’m the nut here. . . But I would rather tell you what I think over just keeping my mouth shut.
I could keep going on, but to me and PLEASE remember, this is my belief and I’m sure there are plenty of people that will think I’m crazy. . . But it is just an opinion. Ok, let the guns sling!
Willcox
I’ll start with Norm: Way back when Lassie was a pup, we installed poly on Norm’s car! Countless times of putting grease on the poly sway bar bushings did not stop the squeaks. Finally we just replace the entire poly for the standard parts and no squeaks, no grease!
On my own personal car years ago I installed Poly! Same issues and one A-Arm shot! Yes I was hard on this car too so I’m sure this added to the problems.
It has always been my “Personal Belief” (and you have to realize that Poly has been around a long long time.) that poly should only be run on cars that are going to be raced around pylons, road raced and or for someone wanting to just run the car hard on a back hills road. Every where poly is installed in a car tightens up the car and I agree that this is a good thing if handling is what you want. If I were racing a car there is no way I would use anything else.
However, it is also my thought that everywhere you replace a part that was designed to have give and movement you also sacrifice ride! A good example of this is the front A arm bushings! The bushing was designed to have movement and not be hard and fixed; something has to suffer from changing them out.
If I remember correctly on some vendor sites there are notes about the poly bushings being used for the snubber cushion? I have seen the rear end on a performance car actually damage the frame bracket from having a poly busing installed in the car. (on a stock car I doubt you could damage this bracket with poly). If this bushing was designed to be solid I would thing GM would have just bolted the rear end front bracket straight to the frame.
You also have to remember that I was raised in a Chevy dealership! I’m not GM brainwashed, but sometimes I think making a better mouse trap can be a down fall. Most of us are driving the cars to enjoy them and lets face it the cars do ride hard enough on their own. Maybe I’ve brainwashed myself and my employee’s and maybe I’m the nut here. . . But I would rather tell you what I think over just keeping my mouth shut.
I could keep going on, but to me and PLEASE remember, this is my belief and I’m sure there are plenty of people that will think I’m crazy. . . But it is just an opinion. Ok, let the guns sling!
Willcox
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
Ok! I’ll probably fire the whole lot of you up with this one! I’m putting on my bullet shield right now, strapping in and oh. .. I’m painting a target on my back too!
I’ll start with Norm: Way back when Lassie was a pup, we installed poly on Norm’s car! Countless times of putting grease on the poly sway bar bushings did not stop the squeaks. Finally we just replace the entire poly for the standard parts and no squeaks, no grease!
On my own personal car years ago I installed Poly! Same issues and one A-Arm shot! Yes I was hard on this car too so I’m sure this added to the problems.
It has always been my “Personal Belief” (and you have to realize that Poly has been around a long long time.) that poly should only be run on cars that are going to be raced around pylons, road raced and or for someone wanting to just run the car hard on a back hills road. Every where poly is installed in a car tightens up the car and I agree that this is a good thing if handling is what you want. If I were racing a car there is no way I would use anything else.
However, it is also my thought that everywhere you replace a part that was designed to have give and movement you also sacrifice ride! A good example of this is the front A arm bushings! The bushing was designed to have movement and not be hard and fixed; something has to suffer from changing them out.
If I remember correctly on some vendor sites there are notes about the poly bushings being used for the snubber cushion? I have seen the rear end on a performance car actually damage the frame bracket from having a poly busing installed in the car. (on a stock car I doubt you could damage this bracket with poly). If this bushing was designed to be solid I would thing GM would have just bolted the rear end front bracket straight to the frame.
You also have to remember that I was raised in a Chevy dealership! I’m not GM brainwashed, but sometimes I think making a better mouse trap can be a down fall. Most of us are driving the cars to enjoy them and lets face it the cars do ride hard enough on their own. Maybe I’ve brainwashed myself and my employee’s and maybe I’m the nut here. . . But I would rather tell you what I think over just keeping my mouth shut.
I could keep going on, but to me and PLEASE remember, this is my belief and I’m sure there are plenty of people that will think I’m crazy. . . But it is just an opinion. Ok, let the guns sling!
Willcox
I’ll start with Norm: Way back when Lassie was a pup, we installed poly on Norm’s car! Countless times of putting grease on the poly sway bar bushings did not stop the squeaks. Finally we just replace the entire poly for the standard parts and no squeaks, no grease!
On my own personal car years ago I installed Poly! Same issues and one A-Arm shot! Yes I was hard on this car too so I’m sure this added to the problems.
It has always been my “Personal Belief” (and you have to realize that Poly has been around a long long time.) that poly should only be run on cars that are going to be raced around pylons, road raced and or for someone wanting to just run the car hard on a back hills road. Every where poly is installed in a car tightens up the car and I agree that this is a good thing if handling is what you want. If I were racing a car there is no way I would use anything else.
However, it is also my thought that everywhere you replace a part that was designed to have give and movement you also sacrifice ride! A good example of this is the front A arm bushings! The bushing was designed to have movement and not be hard and fixed; something has to suffer from changing them out.
If I remember correctly on some vendor sites there are notes about the poly bushings being used for the snubber cushion? I have seen the rear end on a performance car actually damage the frame bracket from having a poly busing installed in the car. (on a stock car I doubt you could damage this bracket with poly). If this bushing was designed to be solid I would thing GM would have just bolted the rear end front bracket straight to the frame.
You also have to remember that I was raised in a Chevy dealership! I’m not GM brainwashed, but sometimes I think making a better mouse trap can be a down fall. Most of us are driving the cars to enjoy them and lets face it the cars do ride hard enough on their own. Maybe I’ve brainwashed myself and my employee’s and maybe I’m the nut here. . . But I would rather tell you what I think over just keeping my mouth shut.
I could keep going on, but to me and PLEASE remember, this is my belief and I’m sure there are plenty of people that will think I’m crazy. . . But it is just an opinion. Ok, let the guns sling!
Willcox
Thread Starter
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Willcox has the rubber kit at a very nice price ($16.00)...
http://willcoxcorvette.com/product_i...ducts_id=24293
...but when I proceed to check-out I see two shipping options:
Express Mail International $45.50 or
Priority Mail International $31.00.
I'm wondering if the shipping calculator is malfunctioning??
http://willcoxcorvette.com/product_i...ducts_id=24293
...but when I proceed to check-out I see two shipping options:
Express Mail International $45.50 or
Priority Mail International $31.00.
I'm wondering if the shipping calculator is malfunctioning??
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
Willcox has the rubber kit at a very nice price ($16.00)...
http://willcoxcorvette.com/product_i...ducts_id=24293
...but when I proceed to check-out I see two shipping options:
Express Mail International $45.50 or
Priority Mail International $31.00.
I'm wondering if the shipping calculator is malfunctioning??
http://willcoxcorvette.com/product_i...ducts_id=24293
...but when I proceed to check-out I see two shipping options:
Express Mail International $45.50 or
Priority Mail International $31.00.
I'm wondering if the shipping calculator is malfunctioning??
here we go..................
Racer
Joined: Jan 2009
Posts: 422
Likes: 1
From: portland or
I have had VBP poly mounts on that snubber for some 15 years, and over the last few months have noticed some clunks in the back end under my butt.....dunno the source yet, but I typically have to hit the gas in order to induce the sound....
busy with other things so not remembering to get under there and check it....did ONCE and tightened hell outta that main bolt...but no change....
busy with other things so not remembering to get under there and check it....did ONCE and tightened hell outta that main bolt...but no change....
sounds like the problem im having
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
it does appear though that someone flipped the 'g' key upside down 
REAR END FRONT SNUBBER CUSHION BOLT SET. Includes Upper and Lower cushions plus the bolt kit to install it. The cushions are rubber as original. It is subbested that you only install Rubber snubber cushions on your car! 0413
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
I was going to check the angles on both the diff and tranny pinions before I put the driveshaft back in. Do you think I'm ok leaving the poly bushings if the pinions are +- 2° or so?
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
Just remember that eventually rubber WILL fail, or you wouldn't be replacing it now. 
The only bushings that will NOT fail over time are solid metal like the aluminum ones offered from Guldstrand.
The only bushings that will NOT fail over time are solid metal like the aluminum ones offered from Guldstrand.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Tech Contributor
Joined: Aug 1999
Posts: 15,177
Likes: 3,995
From: Connecticut, USA
On the trans mounts. This is not a new problem, it goes back at least 5 years since I found it. Sounds like the import ball joint deal that no one knows about- but that's another thread.
Use it if you like, me I have 1 ro 2 sitting here new in the box. They were at least .250 taller and I called ES about it. After getting the runaround, a tech finally told me they were not for the corvette or early camaro BUT no one ever changed the catalog. A few years later I figured they must have had it corrected and ordered another kit from Summit, same deal,same part.
Quality rubber mounts last a long time, given most of these cars now see less then a few thousand miles a year why not use them? I did use poly eng mounts from ES no problem and the trans mount from Prothane was very close in size to the OEM rubber.
Aluminum will also fail over time and exposure, ever see a body mount on the early C3s, they just broke down, looks like erosion.
Use it if you like, me I have 1 ro 2 sitting here new in the box. They were at least .250 taller and I called ES about it. After getting the runaround, a tech finally told me they were not for the corvette or early camaro BUT no one ever changed the catalog. A few years later I figured they must have had it corrected and ordered another kit from Summit, same deal,same part.
Quality rubber mounts last a long time, given most of these cars now see less then a few thousand miles a year why not use them? I did use poly eng mounts from ES no problem and the trans mount from Prothane was very close in size to the OEM rubber.
Aluminum will also fail over time and exposure, ever see a body mount on the early C3s, they just broke down, looks like erosion.
Melting Slicks
Joined: Apr 2008
Posts: 2,625
Likes: 242
From: Russell Ontario
St. Jude Donor '09
I have installed the poly bushings on about 4 vettes now including mine "80" and have yet to hear anyone complain or have problems with them . I even installed them on my top mounts of my differential , Ron
Team Owner
Joined: Mar 2002
Posts: 24,160
Likes: 78
Use it if you like, me I have 1 ro 2 sitting here new in the box. They were at least .250 taller and I called ES about it. After getting the runaround, a tech finally told me they were not for the corvette or early camaro BUT no one ever changed the catalog. A few years later I figured they must have had it corrected and ordered another kit from Summit, same deal,same part.
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
Le Mans Master
Joined: Oct 2000
Posts: 8,897
Likes: 1,357
From: Santa Ana CA
These pieces are THICK and machined from better aluminum than was available when C3's were made. They will NEVER wear out in my lifetime.
Whether you drive your car or not, rubber, on the other hand, deteriorates from Day 1 just due to the ozone in the LA basin.
These aluminium discs help eliminate crossmember movement caused by large tires, high cornering loads and engine torque. And yes, you will make the ride a little harsher and transmit a little more noise into the cab.
Last edited by toddalin; May 20, 2009 at 02:58 PM.
Le Mans Master
Joined: Jan 2006
Posts: 6,506
Likes: 139
From: Butler Pa
Those pieces are probably machined from 6061 aluminum which has been around forever. They use this grade because its reletively strong and is easily machined. But regardless, aluminum corrodes just like steel, just much slower.
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
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/// 