We have a 1975 L82 vette that needs new bushings. Has anyone had the experience of replacing these and would you recommend Rubber or Polyurethane and why? Thanks!

 

I used polyurethane bushings when I did my rearend suspension. I'd do it again, but I don't drive my car everyday, or when it is wet or raining (I still need a new top!) The problem with polyurethane bushings is that they have a tendency to squeak. The prefered way of keeping them from squeaking is to lube them with water proof grease. This grease comes with some bushing sets, you can also buy it at boat supply dealers. It is officially "Marine waterproof lubricant." I've also heard it call Whale Snot. :)
Some vendors sell poly-graphine bushings that are supposed to be polyurethane with graphite mixed in. They are supposed to be self lubricating and aren't supposed to squeak.
The other downside is that the bushings are supposed to make the ride rougher, well I can't testify to that, since my rubber bushings were so worn that any type of new bushings were sure to be an improvement.

 

I've heard the same as Smokehouse69 (the polygraphite sounds particularly appealing).

I've replaced the leaf spring and strut rod bushings with polyurethane (5 years ago) and the front sway bar end links (1 year ago) with poly and have had no squeaks with a lot of wet weather driving (wood :smash: )

I plan on putting in a poly front suspension package in the very near future. Hopefully I'll be as happy with that.

 

I'm right in the middle of doing my front end and after what i've been reading ,Poly is the way i'm going. One added benefit is that after you get the old rubber A arm bushes out you can install the polys in the old sleeves yourself,eliminating a trip to have them removed / installed.I think there is a piece on it in the tech tip section.
good luck ,Bruce :smash:

 

It seems like most people on this forum use poly bushings when they rebuild their suspension, myself included. Most are very pleased with the results. My guess is that when you go from a thoroughly worn out suspension to a freshly rebuilt one, either rubber or poly would produce excellent results!
More than one Corvette Forum member has gone from poly BACK to rubber! Zwede is one person that comes to mind.

As far as I know, there is no way for us to really quantify the performance difference between the two types. I used poly just in case the handling would be better.

-Use all rubber and I'm willing to bet money that you won't be disappointed.
-Use all poly if you are interested in gaining any possible performance advantage and again your not likely to be disappointed.

 

I've redone the entire suspension on my '81, all with poly. Overall, I'd recommend it. The set of issues, as far as I'm aware, consists of: 1) squeaking; 2) ride harshness; 3) handling improvement; 4) durability; 5) originality; 6) cost. My thoughts on those follow.

1) Squeaking. First, all brands of poly bushings that I've checked into are, in fact, graphite-impregnated. The PolyGraphite brand is the most well-known, but the poly bushings I bought from Vette Brakes and Van Steel are also graphite impregnated. I suppose you should ask to be sure before you buy. Second, put gobs of lube on them when they're installed, and they won't squeak. Just don't ever spray them with WD40, or they will start to squeak. TefCone lube (teflon & silicone) is the stuff Vette Brakes recommends. Even if you go with rubber, use the TefCone lube to install.

2) Ride harshness. Poly is harder than rubber. It transmits vibrations that rubber absorbs. Not a lot, but some. You will feel the road surface in the seat of your pants more with poly than rubber, and you will hear more road noise. I'm talking about the kind of noise/feel you get from driving on a gravel-surfaced road instead of, say, a smooth asphalt road. This is probably the most objectionable characteristic IMO, but still not bad enough to make me regret the change.

3) Handling improvement. This is where poly is great! Near-zero deflection means consistent wheel alignment during suspension travel. It's hard for me to say how significant it is, though. I also upgraded my springs, shocks, and rear struts, and rebuilt the steering linkage, all at the same time, and I suppose the net result would still be a big improvement even if I had gone with rubber instead of poly.

4) Durability. Poly will outlast rubber by far. Properly lubed and fitted, I cannot imagine ever having to replace my bushings again. I like that alot.

5) Originality. Poly will never satsify the NCRS judge, I suppose. For people who care about that, nothing but GM rubber will do.

6) Cost. Poly will be 25%-50% more than rubber. And there are lots of pieces, so it really adds up.

I hope this helps. Good luck! :seeya

 

Ya got a lot of good comments there. Personally, I think if you use your corvette for weekend rides on the interstate, go with rubber. Poly won't give you anything. If you like to slide corners or you're simply a fast driver, go with poly.

 

Hi
Looks like you have a '78. So do I. I'm replacing rear strut rod bushings. I'm leaning toward split poly. Do you think I'll have a rougher ride?
Thanks

 

The only poly I would use on a driver would be the engine and tranny mounts. For all other suspension parts I use rubber. It handles well, lasts 25 years, runs quiet, costs less. just my .02 but when I started driving vettes 30 years ago they didn't have poly and sure handled pretty dam good.Bottom line = it's your car and money,good luck.
Gary

 

I redid my bushings w/ poly, and I swear ican feel an improvement...as for squeaks, I too was afraid about hearing them, but not once have I thus far! Go poly!

 

Poly's biggest advertised draw is less deflection than rubber in a hard corner. Our engineers on this site (Norval, Zwede, Twin Turbo, among others) have pointed out many times how much the front ends of C3's will flex the frame to the point of causing cracks. The reduced deflection of poly means that the forces are not absorbed by rubber, rather transmitted to the frame, causing more deflection and greater changes in steering geometry. Unless a vette has a full tube frame with poly, or added bracing across the front of the frame from control arm to control arm, I'm sure the engineering will show worse results with a C3 when poly is installed.
The better handling and feel in the seat of the pants is mainly from new bushings and alignment compared to the previous bushings and setup the car had before the work was done to it. Yes poly will only have to be done once, but good rubber installed correctly will last 25+ years, and the majority of us on this forum will not own a single car for that long.
My .02

 

If you can hear the Poly squeak, your exhaust isn't loud enough!

 

If I could segway into another question ...

Which poly bushing packages would ya'll recommend? I was looking at getting the Prothane front & rear package, but then I seem to recall someone mentioning a poor fitting with them? *shrugs*

 

i'm happy with the ones i got from ecklers....

 

I have the energy suspensions poly kit on the whole front end, and its tight. I did use IZUZU grease..(suppose to be waterproof and known to get rid of squeaks at dealerships..maybe a myth) never had one squeak.

 

Who actually makes that one though? Do you happen to remember?

 

I installed the complete front/rear prothane kit prob 4 months ago.

All the bushings/bolts were high quality.

I even forgot to lube the front a arm bushings, and have not heard a single squeak.

 

I have a Prothane front control arm bushing kit, I got it in a front end rebuild kit, they are "JUNK", I have had to many issues with the installation of them, you have to remove the old outer sleaves and press in the new urethane outer sleaves, they are sloppy fitting, they swedge over the shaft shoulders and squeek while on the bench in a vise, on one I have shortened the bushings to clear the shaft shoulders, another has them installed without being cut to fit, I have just ordered new rubber bushings to install on my upper and lower control arms, this rebuild is a pain in the a$$ and I want to do it only once.

 

Poly Poly Poly Poly Poly Poly Poly Poly Poly - so I like Poly more

 

I have the energy suspensions poly kit for the whole suspenesion and it was a pretty nice kit. All the bushings had the part numbers molded into them with a reference sheet included for helping decide where they each go.

The problem with rubber (IMHO) is that they dry out & crack, sometimes falling apart and leaving nothing in it's place if let go for too long. Also, the a-arm's were a PITA to change and the longer I can go without having to change them again the happier I'll be