O.k., So I took my 75 Vert.to a Vette mechanic (Marty in Gainesville Fl.) to get a price on Vintage Air install. Way expensive with labor, and he said I should keep and fix the factory air.
I was impressed with his clean, orderly shop! I'm thinking-Great! I've finally found a good Vette mechanic.
He took the car for a spin and determined that the rear spring and shocks need replacing (no surprise).Also needs brake work.I told him I wanted to get the rear and body bushings and I think the clunky snubber bushing redone anyway.
I told him I wanted to replace all with rubber VS poly, as I've heard a lot of rough ride stories with poly.
He has been -working on -racing -and restoring (high dollar) Vetts ONLY for 37 years. --He's mostly an original/ correct type guy.
He wants me to use poly. Says "The car rides on SPRINGS and SHOCKS -NOT bushings". And also, "You want little GIVE in these parts".
OK, this sounds logical to me, but I think at least the rear end front snubber bushing should be rubber.

OPINIONS please.

 

I ran into the same sort of shop back in san antonio. I took mine in there after the crate motor install and he wouldnt even touch it because it had a holley on it instead of a qjet. He said that he only works on vettes that are original so he has a baseline to start with. That being said, I had poly bushings in a car and I really didnt notice much of a difference between new good rubber and poly. Except for the engine mounts. The engine didnt rock as much with poly mount bushings

 

I have poly on mine in the rear suspension and really never found any difference,Ron

 

The factory never used poly and they have spent millions in engineering.

My suggestion is to stick with factory rubber bushings.

Just my two cents.

 

Sounds like he doesn't know quite as much as he makes out. There's very good reasons why rubber was used and good reasons to stick with it.

 

When did (about year) poly bushings become available?

 

I'd also stick with rubber. On most of our vettes, it lasted 30-40 years.
By the time it needs to be replaced again, most of us won't be here to worry about it.
Glenn

 

That would be me

 

At least prior to 1990 when I started to play with mine. They were the 'big thing' back then. Why?

 

Having used poly bushings, I gonna cast my vote for rubber. Far less potential for problems with OEM rubber.

The engineers at GM knew what they were doing and got it right IMHO.

 

I wouldn't go that far. It is cheaper to produce rubber bushings for one thing and for another did any car back then come with the poly bushings?

 

I would. Rubber was chosen and poly rejected for good solid engineering reasons. Still is.

 

I'll agree that if comfort is the overriding priority, one should just stick with fresh rubber. However, if you're willing to compromise some comfort in favor of improved performance it really depends on how much you wish to reduce compliance and at what location(s) as to whether you should consider rubber, poly, delrin, rod ends, sphericals or blocks and such. When it comes to performance, there are places where rubber is simply not the best material.

 

agreed, which is why street cars use rubber now. more compliance, better feel, less harsh ride. its not because they are "better" it is just what 99% of those that buy street cars want. Engineers might think product A or B is better but it is marketers that determine what actually gets put into a car.

 

Well, here is some of my experience with poly bushings:

Rear spring bolt cushions that cracked and shattered after less than 1 year. Replaced them with OEM rubber - no problems since. Ok, maybe they were just POS inferior grade poly (bought from one of the major vendors on this forum - won't say who because they were not the manufacturer and I don't think it is their fault).

Poly bushing caused one of my upper A-Arm bolts to walk out. It is a real exciting experience to have that happen while going around a corner. Fortunately I was less than 1/2 block from the house and going about 10 mph when it happened. I got lucky - nothing damaged or broken, couldnt find the bolt or washer though. This is a known issue with poly bushings and the bolts must be installed with red loctite to help prevent this. I still periodically check all the bolts. Hopefully the installation instructions for the bushings mention using loctite now. This issue does not happen with the rubber bushings. Do a forum search - I'm not the only one this has happened to.

Now, the bushings are starting to squeak a little whenever I go over a speed bump. Hmmmm... a job coming up to re-grease them or replace back to rubber. The OEM rubber that lasted 30+ years never squeaked.

So, maybe if you are racing your car, poly has some advantages in stiffening everything up and helping improve handling a little . If you are not racing, and your car is just a daily (or weekly, or monthly) driver, whats the real benefit?

 

Yeah, it was a big thing when Poly bushings came out back in the 70's and 80's. The advertising literature claims better handling. Lee Greenwood was a big Corvette racer back in the 70's and early 80's and also produced tricked-out corvette mod products. I'm sure anyone that's read many Corvette books or has been around a while has heard his name mentioned more than a few times. Anyway, I recall a series of very comprehensive articles he wrote for Corvette Fever back in the early 80's on how to make your Corvette handle better (for street and for racing). One of the first articles was to inspect and replace worn bushings for C3's. He addressed the Poly vs OEM-type rubber. His personal experience using both was that Poly did provide slightly improved quick response (very slight) over OEM, but did not increase lap times at all or improve his racing. He also indicated that they did not last nearly as long and he therefore stuck with regular OEM bushings. He advised anyone wishing to prep their car for the track to do the same. That came from years of experience on the track. I would do the same. Besides, for general driving around, they also make for a slightly rougher ride he indicated.

Mark G

 

put poly on sorry i did , a frame bolt backed out lucky no damage hate them seems to have caused a bounce on right tire have to ck bolts on regular basis used lock tight also going back to rubber soon
money wasted

 

Poly vs. Rubber

http://www.google.com/url?sa=t&sourc...83RxRRvnVK-5xQ

 

If you're going to plagiarize,

http://www.automedia.com/Upgrading_Y...es20020701pb/1

at least steal something that doesn't make you look like an slimy sales guy.

 

Actually I got it here. Not trying to sell anything but my opinion, but thats what we do on this forum.

http://www.google.com/url?sa=t&sourc...83RxRRvnVK-5xQ