Polygraphite or Rubber Suspension Bushings

Rubber or Polygraphite

  • Rubber

    Votes: 36 57.1%

  • Polygraphite

    Votes: 27 42.9%
  • Total voters
    63
  • Poll closed .
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JGC403

JGC403

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For those of you that are familiar with using and driving a car with a polygraphite suspension, is it worth the extra cost? Would you do it again?

I live in PA and our roads aren't the best. So lots of bumps, cracks and potholes in the roads. I use the car as a daily driver and take it to the drag strip now and then.

With the road conditions that I drive on and what I use the car for. Is it worth the extra cost of polygraphite and sacrificing some ride quality?

I know rubber deteriorates over time, but my Grandfather told me of this stuff that you could put on rubber bushings to keep them from or slow down the deterioration process. So that wouldn't be to difficult to do a couple times a year to keep them in good shape.
 
1968FormulaS340 said:
Bad roads and a daily driver would = rubber bushings for me.
Click to expand...

I used to swear by Polygraphite. After years of weird noises and the lack of fore / aft retention of the lower control arm, I'm replacing the last polygraphite bushings in our last "A" body to have them, with MOOG bushings. I still like polygraphite for sway bar bushings.
 
polygraphite makes a weird clunking when you hit bumps in road very annoying
 
Daily driving with anything besides rubber will create all the problems that are mentioned, and much more so on the PA roads. (I drive up there regualry so know.) It will fatique other parts of the car too. I would not even consider the poly in your situation.

And BTW, I rally for my competition fix, and running poly on gravel/dirt roads at speed just tears up all the surrounding suspension parts unless you rebuild them with heavier metal, and the bushing material doesn't last worth a hoot under really hard use; they just tend to 'flow' and distort.
 
I went from all poly to Moog's rubber UCA Offsetbushings recently.
I encounter an annoying high number of speedbumps every day and some of them have some ridges worn in them which really give a good hit to the suspension.
With the rubber Moog bushings the ridges are toned down to an acceptable level again.

The LCA's and strutrod bushings still have poly bushings.
 
What do you want from the car? Better handling or cushier ride?
1. If you want to stiffen up the handling a bit: go all poly except for the upper/lower control arms and rear spring eyes/shackles. These are the suspensions main pivot points and rubber will be more compliant and transfer less road noise into the chassis. Poly Strut Rod bushings can cause issues with LCAs being pushed back as they are a universal part and in some applications are to thick. This occurs because LCA Ploy bushings allow the control arm to "slide around" on the pin. The strut bushings can be cut down but my preference is to keep the LCA bushings rubber even in a performance application.
2. For best ride/noise level on ruff roads: all rubber.
3. Performance over ride/noise: Poly except LCA.

(Edited for strut rod bushing)
 
No contest - Poly - It will last longer under the pounding conditions as well as drastic weather changes over the seasons. Gotta factor in replacement time & costs for rubber as well.
 
I've got well over 150k on a complete poly set including LCA.
No problems.
And I hit two traffic islands straight on at 45 MPH on the drives side.
Bent two cop rims on that one and knocked the front tire flat.
Only had to replace the upper control arm since the alignment man said it was bent.
(Also the wheel bearings as a precaution)

I've put poly in all my cars.
No problems.
 
rapom65 said:
What do you want from the car? Better handling or cushier ride?
1. If you want to stiffen it up the handling a bit: go all poly except for the upper/lower control arms and rear spring eyes/shackles. These are the suspensions main pivot points and rubber will be more compliant and transfer less road noise into the chassis. Poly LCA bushings can have issues with pushing the control arm back as they are manufactured as a universal part and in some applications can be too thick. They can be cut down but my preference is to keep them rubber even in a performance application.
2. For best ride/noise level on ruff roads: all rubber.
3. Performance over ride/noise: Poly except LCA.
Click to expand...


I want to improve the handling, I want it to handle better than it did 38 years ago when it was new.

I'm going to be putting on torque boxes, frame connectors, welding up K-member and the Firm Feel steering box support.

I want it to handle better that is why I considered the polygraphite bushings. But just worried about how the rest of the suspension components will hold up with the roads I drive on.
 
What car are we talking about? Torsion bars? rear springs? Sway bar? The polygraphite bushing should hold up. the problem is the noises and the fore aft movement of the lower control arm with the polygraphite bushing. I've been running them since they came out on 4 different cars. You had to reuse the metal and just replace the bushing, even on the upper control arm bushings. The last car I did, the 66 Formula S, is MOOG except for the sway bar buttons and I love it.
 
66fs said:
... and the fore aft movement of the lower control arm with the polygraphite bushing....
Click to expand...


Do you have any (written) evidence of this, or just hear say?
Because in order for the LCA to be able to move, the entire torsionbar has to move along with it.
For the torsionbar being able to move at all, all the springload would have to be unloaded so it looses it's bind with the LCA-socket.
The only thing what could happen is the bushing might trying to work itself out from between the moving parts.

In the 3+ years I've been driving my Dart with the poly LCA's I've seen no evidence of this happening yet.
My Dart encounters some 40-50 speedbumps everyday with a good number of roundabouts, so the suspension gets quite a workout.
 
Saw it with my own eyes on our 67 Barracuda, all polygraphite bushings. Think about it, what holds the polygraphite bushing to the pivot pin? It is not a press fit like a Lower Control arm MOOG bushing. In practice, there are tens of thousands of miles on the car including cross country, all day driving, trips. It is just a bit disconcerting. If I remember correctly, it was in reverse. I would say that when you were driving forward, all the forces keep the lower control arm where it should be. The strut rod kinda holds it in, but I'm replacing them soon when I replace the 273 with a 340. Hopefully this summer. The torsion bar just fits in a socket in the lower control arm, it does not index the bar fore or aft.
 
JGC403 said:
I want to improve the handling, I want it to handle better than it did 38 years ago when it was new.

I'm going to be putting on torque boxes, frame connectors, welding up K-member and the Firm Feel steering box support.

I want it to handle better that is why I considered the polygraphite bushings. But just worried about how the rest of the suspension components will hold up with the roads I drive on.
Click to expand...

Then go Poly except at LCA for the reasons given above. You will have a trade off in suspension compliance and increased chassis noise for the increase in handling. Soon you'll be wanting quality shocks, then increased spring rates (TB/rear leafs), then sway bars, then...... Your opening a can of worms!

Don't worry about stock suspension components holding up to Poly bushings as long as they are in serviceable shape to begin with.
 
BigBlockMopar said:
Do you have any (written) evidence of this, or just hear say?
Because in order for the LCA to be able to move, the entire torsionbar has to move along with it.
For the torsionbar being able to move at all, all the springload would have to be unloaded so it looses it's bind with the LCA-socket.
The only thing what could happen is the bushing might trying to work itself out from between the moving parts.

In the 3+ years I've been driving my Dart with the poly LCA's I've seen no evidence of this happening yet.
My Dart encounters some 40-50 speedbumps everyday with a good number of roundabouts, so the suspension gets quite a workout.
Click to expand...

I believe it was member Autoxcuda that had info and pictures on the problem and instructions on how to modify the poly strut rod bushings. This was on his old web site about the development of his Cuda from street car to track car. I had the link saved but now it doesn't work anymore. As they say "it didn't happen without pictures".

(Edit: Changed LCA bushing to strut rod bushing)
 
A pressed fit bushing does not constitute lower control arm "retention", strut rods do.
The loose fitting poly LCA bushings and differences in strut rod bushings are well documented, likewise the cure.
With the poly stuff, cut down the strut rod bushings per autoxcuda, as mentioned, or just use adjustable struts.

I voted poly, I've been using them for years.
 
pauly v.100 said:
A pressed fit bushing does not constitute lower control arm "retention", strut rods do.
The loose fitting poly LCA bushings and differences in strut rod bushings are well documented, likewise the cure.
With the poly stuff, cut down the strut rod bushings per autoxcuda, as mentioned, or just use adjustable struts.

I voted poly, I've been using them for years.
Click to expand...


Actually a press fit bushing does. Try to move a lower control arm with a press in bushing, or even get an original bushing out. The strut rod is at a angle and a moments arm length from the pivot. Thank you for bringing up a couple solutions to the problem I noticed. I've run these things for probably 20 or 30 years and many miles. I know enough not to dispute autoxcuda, but as you said there is basis for what I saw. I'm not up for "fixing" the problem myself. I'll be running MOOG press fit rubber bushings. I've been there before most guys and have a lot of experience with polygraphite, it is not worth it to me anymore. I am not building a race car, my cars' handling is very good, but I started with a Barracuda Formula S to begin with. I am only presenting one view and opinion. The OP will make up his own mind with his intended usage of his car.
 
1968FormulaS340 said:
Bad roads and a daily driver would = rubber bushings for me.
Click to expand...

I agree. I have seen some here say there's no difference in road feel between poly or rubber. Either they have never driven the difference, or they have dead butts.
 
I would use Moog rubber any day, poly will last longer, but how many miles a year do we really drive these car's? I would also agree that the poly bushings are noisy my car road like a lumber wagon with them in it!
 
jtkaaa07 said:
I would use Moog rubber any day, poly will last longer, but how many miles a year do we really drive these car's?!
Click to expand...

I have Moog offset UCA bushings to get the caster at 2*, Moog LCA bushings (the cross section area is so thin, there can't be much deformation), Moog strut rod bushings, ESPO HD rear springs w/ rubber front bushings. .920 T-bars.

The only poly I used was front sway bar links and pivots, and rear spring shackle bushings.

Just replacing worn deteriorated stock parts with new rubber Moog pieces is a huge improvement on a 45 year old car. I drive on bad roads too and my opinion is unless you are getting track time often, no need for poly on a driver. How often do you drive your car 100% on the street anyway? I don't trust the all-in-one kits because you don't know what you are getting but Moog is always good and it fits.
 
I don't trust the all-in-one kits because you don't know what you are getting but Moog is always good and it fits.[/QUOTE]


Exactly, most of theses cars have part's from different years, and even different models! I just ordered mine right from Napa, and I had to run back several times to compare sizes, kind of hard to do when you order a kit!
 
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