OEM or urethane?

[panhead]

I'm going to redo my supension this winter and I was looking for some feedback on bushings, I've been told by several people that although the urethane bushings outperform thier rubber counterparts, they have a tendency to squeak, even when lubed with silicone grease. While I'm about 60% ride quality and 40% performance, I really don't want to hear my vette squeaking over every bump! Any info greatly appreciated!!

 

[Ken]

I've redone mine (at Guldstrand's) in urethane Kenny, and I have not experienced one squeak or groan in the four or five years since.

_ken

 

[Yoda]

panhead ~ Welcome to the Corvette Action Center Community ~

Here is a post from a past discussion about this subject and suspensions. If you would like more reading you can go to the "Search Menu" at the top of the page just below Corvette Action Center Forums and enter Poly Bushings..

Good Luck ~ Welcome aboard ~ and ~ enjoy the ride

The choice of 460 lb/in. fronts and a 330 lb/in. rear spring would be about right for a street high-performance small block. That is not road raced or autocrossed.

Stabilizer bar choices sould be 1-1/8 front bar and either a 1/2-in or 9/16 rear bar.

As for bushings, in the front, I prefer the Global West Del-A-Lum. It's the best street high-performance bushing there is. They tend to be a bit pricey, however, so graphite-impregnated polyurethane is the next-best choice.

At the rear, I like Vette Brakes and Products' "Smart Strut" kit along with polyurethane trailing arm bushings. Again, make sure any poly bushings are the graphite-impregnated type. They are less liable to squeak and groan in cold or damp weather than are the non-graphite units.

Keep in mind that with C3s, any bushing with compliance lower than the stock rubber stuff, will transmit more road noise and harshness into the cockpit. Those cars are already harsh and noisy so if NVH is something you already don't like, I'd stick with OE rubber bushings.

As for shocks, I've tried a number of different brands in my years as a C3 owner and I think the best choices are Bilstein or Tokico. If you go with the Bilsteins, you have a choice of two different valving choices. If you are mainly an easy driver but make an occasional sporting drive with on a club run, use the "HD" Bilsteins. If you run the car hard a lot, use the "Sport" Bilsteins.

 

[Tom73]

I figure that if the original rubber lasted 25 years, why change. Unless you are autocrossing there is no reason to use anything other then OEM style (unless you are just trying to project an image )

tom...

 

[Ken]

You'd be amazed at the difference in handling Tom.

_ken

 

[Tom73]

You'd be amazed at the difference in handling Tom.

I know there is a world of difference when you replace your worn OEM with new urethane. No question about that. But I don't think that there would be that much difference between new OEM and new urethane. And for street use I don't think it is worth the added expense (and posibility of squeeks )

tom...

 

[panhead]

Thanks!

I appreciate all the replies and leads to more info.
This is my first experience in a forum and I'm really impressed at how it works.
Hey Ken, LOVE that pic of your Vette in NYC!! That one is priceless.
Will get pics of my '85 wideglide on my webpage soon too.
Here's to Vettes-n-Harleys!

 

[Ken]

The white Vette with the WTC behind it ain't mine, I got a coupe. I just thought it would be appropriate in light of 9-11.

_ken

 

[resto75]

Poly bushings

Hello Panhead,

Welcome to the board. I am considering replacing my bushings in my 75 with poly. My old rubber stuff is cracked and dried out.These have been replaced by a prior owner but I don't know how long ago.
From what I have been reading over the last few months is that poly is the way to go for durablility and performance. There seems to be no question about that from most people, however squeaking can be a problem. I have no use for a car that squeaks so I will think about this a while longer. It appears if you use the graphite impregnated ones this helps. I have also heard that the front sway bar is a big time squeaker, so get the bushings with the grease fitting in the bracket so it can be greased.
I have been considering the Hyper-flex kit from Energy Suspension which contains most everything you need except the sway bar bushings. There are several different size sway bars so they need to be ordered for your diameter sway bar. There are a number of other suppliers of bushings but the above mentioned seems to be the most complete.
As control arm bushings are the hardest to replace I want something that going to last. As for the easy bushings I can always change them back to rubber if I decided to.

Let me know if you get to Florida with that wideglide, we can go have a . I have a Classic and have been riding for years.

 

[SARGE81]

Polyurethane vs. Rubber

I did my entire suspension (front + rear) in my vette a couple of years ago with the graphite impregnated polyurethane bushing set I bought from PST. They even warranty the bushings for 20 yrs. I haven't heard one squeak yet. And the car handles like its on rails. Soooo...thats my 2 cents. Sarge :xmas

 

[KenSny]

Recently did front and rear sway bar bushings with poly, no squeaks.

 

[corvettecrew]

I replaced mine with poly too, and like everyone else has said, no squeaks.

The bushings on the front of the differential were all puffed out and soft and squishy. That was one reason I went to poly. I don't think that poly would do that.

I am not sure what happened to those old rubber bushings. Maybe some oil got on them and it decomposed or something. It is really weird.

Has anyone else had this happen?

 

[Ken]

I am not sure what happened to those old rubber bushings. Maybe some oil got on them and it decomposed or something.

Bingo! Among other things, like "old age". Urethane won't do that.

_ken

 

[sscam69]

resto75

I replaced my bushings on my 79 with the energy suspension bushings. I bought the whole set. I replaced the front took her for a spin. No Squeaks. The car wasn't aligned so i can't say to much on the difference. I am going to put composite spring in back and finish installing the rear bushings let you know what happens resto.

 

[corvettecrew]

I also put on a composite spring. The ride is alot better and the sagging went away.

I'm not sure if the spring is what made the ride better though, because I also replaced all 4 shocks.

It was alot of work getting everything aligned, are you going to do it yourself?

It was too expensive to have a shop do it, in my opinion.

Did you replace the shims for the trailing arms or use the old ones? I bought some new ones from Mid America and they barely gave me enough. It kind of made me mad!

 

[Brutus]

Poly

Poly all round on my 77. Wouldn't have it any other way. I deliberated long and hard and asked all the same questions. Went with poly bushings and never regretted my decision once.
There are too many variables that dictate rubber is an obsolete option.

 

[panhead]

Thanks again to everyone for the advice, I think I'm gonna go with urethane bushings all the way around, I already have energy susp. motor and tranny mounts and I was impressed with them so after a few more cruises I'm gonna have to put her up on the stands and start this winter's project, I can feel the vette withdrawls starting already!! :crazy :J

 

[Tom Bryant]

I'm installing polygraphite bushings on all locations on a '69 C10 project I'm working on. I was told by Dave, former GM at Guldstrand to use marine grease on them to keep them from squeeking. It is waterproof and won't wash away. Some of my bushings came with grease zerts installed.

Tom

P. S. As of now a C10 is still a pickup truck. In 5 more model changes it will be a Corvette.

 

[Eric]

Whenever I get to that part of my project, I'll probably be going with poly. I know that in sharks it will make you feel everything but it is a sportscar. The one thing that scares me is unearthing all of the other squeaks that may result from a stiffer suspension - body, interior, etc. The high side of that is that it will force me to find all of the little squeaks and kill them amking for an overall better car.

 

[magicv8]

I only have poly bushings in my adjustable strut rods, and the strut rod vendor recommends reinforcing the GM welds on the differential mounting bracket - due to the high shear stress transmitted through the poly bushings. I reinforced the welds before installing. I love the adjustable strut rods.