Pros & cons of polyurethane suspension parts

[hetman]

Specifically, has anyone tried P-S-T's "polygraphite" brand graphite-impregnated suspension bushings? How good are they? Do they solve the problem I've heard about that pure polyurethane will squeak and/or bind in demanding situations?

I have to replace all the front end parts in my 74 Monte, and was thinking of buying one of PST's kits, and am considering getting their polygraphite set. What have I got to lose? I also need to replace the rear control arm bushings and I only see polygraphite replacement parts from them, no stock rubber for the rear (maybe I'm blind?), so if I'm going to go with their polygraphite in the rear, I thought it would be OK to go with that in the front as well. Plus, I see they have body bushings only in polygraphite, which I also need for a couple cars, and for 4th gen Montes, those are basically unobtainable in NOS rubber, so I'm essentially forced to go with polygraphite.

So has anyone used PST's polygraphite? How does it work?

[rj]

On a Monte Carlo - no.
On a Tri-5 Chevy - yes.

Well not me personally. But I have talked with other members of Chevy talk.com who say the urethane or graphite bushings are far & above the stock rubber replacement bushings.

One thing we all agreed on was replace with rubber bushings and expect to re-do the bushings in a few years. Replace with urethane or graphite and be done with it for pretty much the rest of the time you own the vehicle.

You do want to lubricate any urethane or graphite bushings before installation. This eliminates the annoying squeaks they tend to give where stock, rubber bushings do not.

I know I have personally installed new OE rubber replacement bushings in A-arms that went in to storage. Never used. These bushings deteriorated to the point they will need replaced again if I ever want to use the suspension pieces I installed them in. Very irritating.

I have used urethane bushings in the rear suspension of a couple of my cars and I love them. They are from Prothane who manufactures bushings like Energy Suspension does.

[hetman]

Thanks for relating your experiences, RJ. It's exactly this kind of information that I'm looking for. So I can rest assured that I won't be making a colossal gaffe by installing polyurethane all around the car? I don't want to compromise the handling or safety of the car, nor have to redo it because of that. The improved handling and safety will be bonuses. What kind of grease is used when installing the bushings? Will it need to be regreased (or is this even possible) at periodic intervals?

[95gts]

I read that rubber gives the car a better ride, poly is a harder ride. If your looking for ride quality, rubber is better.

[rj]

Well, I've heard that the improvements in handling the urethane or graphite bushings give outweigh the harsher ride they tend to give.

The urethane or graphite bushings are going to give what feels like a harsher ride cause they aren't allowing the suspension components to travel or flex like they would with OE replacement rubber bushings.

I do know I put urethane leaf spring bushings in one of my '57s back in 2004. One summer day while driving to a cruise in I happened to notice the car seemed to "feel" like it was glued to the road. The only parts that I changed when I did the bushings install was the urethane bushings. Everything else I worked on was just a clean up and paint of the parts I re-used on the car.

Leaf springs, air shocks, shackles, lower shock plates were all parts that were already bolted to the car. I just cleaned and painted all of them.

Just to give some additional information...........

The car has 7 leaf, leaf springs on it. They were beefed up by some previous owner long before I got the car. Probably whrn they drag raced the car. A lot of people I mention to them the car has 7 leaf, leaf springs all say they'd feel the car has a harsh ride to it. I tell them that's more then likely true. So adding the urethane leaf spring bushings won't matter any to the ride quality. And having air shocks on the back will only add to the car riding harsh. I only run between 10-25 pounds of air in the air shocks. They can't be adding to the car having harsh ride that much.

[twomanymontes]

Sorry for may late reply, I have installed poly bushings in a Honda at work one day, They are quite durable and do improve the handling ALOT!!!! But like Joe Stated, they are harsher on the ride.

I have never delt with the PolyGraphite bushings. So I can't comment on them. But that is something I plan on doing to the SS in a year or two.

I know Jamie, Hardrocker, was thinking of doing something like this.

[95gts]

Yes it all about what your after, both have there up and down points. I myself like a softer ride, why I stayed with rubber.

[rj]

I think the Tri-5 owners I've talked with who went with graphite said they are a bit softer versus the urethane bushings?

I know I read where someone or maybe a couple owners said they went with urethane body mounts and stock OE rubber bushings in the suspension on their cars.

Some don't realize over time the body mounts on a car tend to smash flat and split. Replacing the mounts improves the ride inside the car. It can also be some major work replacing these if the body has seen a lot of road salt in it's life. The bolts in blind holes can be the hardest to get out.

If the body mounts weren't so darn expensive I'd do this to just about all of my cars. But even the rubber mounts can run in to some cash. Let alone using graphite or urethane.

[hetman]

As far as rubber body mounts are concerned, I can't find them for the 4th generation Montes. They are basically unavailable, and so one must turn to polyurethane/polygraphite, which PST does carry (and probably other manufacturers). I haven't tried finding them for 2nd gen cars.

I wouldn't have any trouble using all polygraphite bushings and mounts if I knew for sure there wouldn't be any dangerous effects, which I have heard of the rear upper control arms binding in some maneuvers with polyurethane. How often would the car be exposed to this potential issue, I don't know, but I suppose if you didn't auto-cross the car, it would almost never take place, making it a virtual non-issue, which in turn would sway me more in favor of getting all polygraphite bushings and mounts for the whole car. That's why I'd like to hear if anyone has heard of this so-called "binding" of the upper control arms (I have never experienced it, but have also never driven a car with all polyurethane bushings either).

Another question is if PST's polygraphite bushings are superior to regular polyurethane. From what RJ is saying, some people report that this material is indeed different, and has different ride qualities, and perhaps also minimizes this "binding" effect.

So, in trying to make a choice, I would probably have to go with all polygraphite because rubber is unavailable for many of these bushings, and I'd prefer to have the same type of bushing everywhere. Another factor in the decision is since I've never tried polyurethane/polygraphite, I might choose that simply to see what a car feels like with them, sort of like an experiment, so I would know first-hand how a car handles with that material, and go from there. One more reason to choose polygraphite is for the noted longevity, as well as better control of the car, which I am in favor of. I'm not a particular fan of the boat-like ride quality of most American cars until the 1990s, though Montes, especially 2nd gen Montes, handle really superbly.

I think I'll give Mark Savitske a call at SC&C to see what he'd recommend. Not too many after-market parts are available for 2nd gen Montes, but he might have something. For 4th gens, he has incredible improvements available.

[twomanymontes]

Mike, Good luck finding anything for a 4th gen thses days. Once you get then installed I expect to see a complete write up on the installation and the outcome.

[rj]

Just to get additional information, you could contact the tech support at Summit Racing.

See if they can add anything to what's been said about OE rubber vs graphite vs urethane?

Summit can also look parts up that aren't nessesarily listed on their web site too. That's how I found out about the Prothane urethane bushings for Tri-5 leaf springs. I didn't see these listed in the Summit catalog.

Just some added info.
If anyone knows of Classic Chevy club in Florida? They've been around since 1974. Currently they're owned by Eckler's who also owns the Camaro and a Vette club.
Anyways, I bought the urethane leaf springs bushings from Classic Chevy for my other BelAir Hardtop. Cost was $40.
Then I find out Summit can get these same bushings too. So I bought another set.
When this second set arrived from Summit, it's the exact same bushings in the exact same packaging I got from Classic Chevy. Only the Summit cost was $19. Half the cost of Classic Chevy.
Believe me I was pissed.

But it pays to shop around before you buy.

[drix76]

We've had 2 of the 3 Monte's re-done with full front end kits, shocks, and springs, from PST. they make great stuff. The cars ride like pillows!! But we got OEM stuff, not the Poly stuff. I'm curious about it too since I want a little better stuff in my 76.

[HardRocker]

I never did get around to ordering the kits yet. Too many other things sucking the money out the wallet at this point.

But here is a price comparison I was doing between 3 different suppliers. I do not know how the quality compares between them all but, if you take a BIG assumption and assume they are the same quality and possibly from the same molder.... here is how the prices and kits compare out... note that note everyone's "master kit" includes the same things and you may need to buy various bits separately, as I tried to tabulate in the below.

X's indicate that those items are part of their main kit, then prices are shown for the additional items that would be needed. NA for not available.

[85t5mcss]

Looks like u can rule out 1, too bad u don't have any feedback on the suppliers. Personally I don't know anything about any of them. Good luck getting it narrowed down. The only real benefit of PST is no shipping and could buy individual pieces as necessary.

[HardRocker]

I did a PST kit on the '80 Monte years ago (natural rubber kit) and everything arrived on time and was of good quality. No issues with the parts. I have since ordered springs from them for the rear of '78 and the '75 and received quickly.