I don't want this to be about originality. I see all the suspension bushings come in rubber or polyurethane. I am in the process of relpacing some of my 68 bushings. I know the car rides rough by its nature, but anything to make it a bit softer is a good thing. The rubber bushings I am replacing are 52 years old. Is the point of poly bushings, is that they last longer?

 

No, the theoretical point is that they are stiffer and provide for a stiffer ride. If you are after a softer ride, stick with rubber.

 

Poly mounts are hard like aluminum. Wouldn't call Poly a cushion. Used them all around on my '70 GTO and it rode like a tank.

I'm in the process now of using rubber mounts under the passenger compartment and poly at the very front and very rear mounts which are in the weather. Had the weather eat up my stock rubber rear mounts to the point they were just crumbling off.

 

You will see arguments both ways.
Some prefer rubber and some poly.
Which ever you choose, buy good quality.
Van Steel offers the best quality Moog rubber and Energy Suspension poly.
Give them a call, and they will recommend the best option for you related to your use of the car and driving style.
As stated above, in some areas of the suspension and steering components poly may work better than rubber or vice a versa.
Good quality rubber like that installed by the factory could last another 50 years and out last us all.

 

I've used both on several different applications and have to say I prefer the rubber every time.
Many complain of squeaks with the poly bushings and I found this to be true on the last car I did with poly control arm bushings. They would squeak quite loud when turning and going over a driveway curb, for instance. Very audible outside. I sprayed them down with PB Blaster and they would quiet down but a few weeks later they would start to squeak again. I just did all the suspension on my '65 and stayed with rubber. Nice fit, easy to work with and no noise.
Greg

 

I have had poly upper and lower control arm bushings for 15 years now on my 78 C3 and would never go back to rubber since the rubber allows way too much unwanted movement in the front end. I was shocked at how much more positive the steering and suspension of 78 C3 felt after the change to poly. There was Zero increase in ride harshness with the poly versus rubber in the control arms. My Prothane poly bushings are quiet as a mouse and have never squeaked...15 years now. You must use blue loctite of the control arm bolts to prevent unwanted bolt loosening with Poly.

Anything you can do to mitigate the flex of the C3 frame such as poly control arm bushings and a spreader bar in the front is a giant improvement of the OEM design. If you want a soft rubbery ride and handling C3, then go rubber. If you are looking for performance, there is no contest,GO with poly bushings...NONE.

 

On my 69's front end I went with Van Steel poly in the control arms and sway bar. Never heard a squeak and they seem to ride very well. It appears that the quality of the poly matters most.

 

I can't hear any squeaking over the headers. I put poly everywhere except the trailing arm bushings (rubber) and strut rods (heim joints).

I've heard from people with both that the later C3s are much more plush than the early ones. If you want a softer ride, consider replacing the rear spring with a VanSteel low-arch composite spring.

 

FWIW-The 63-82 C2/C3's are all the same chassis frame and suspension. There is zero difference in these areas between all the C generations and frame/suspensions. There is a difference in the body to frame mounts in the early 68-82's of solid versus rubber mounts which has zero effect on how the cars handle/steer but will make the rubber mounted bodies absorb more road shock and appear to ride slightly softer but the difference is VERY minor.

What is different amongst all the C2/C3's is the front and rear spring rates/front and rear sway sizes (if you are lucky to have a BB or SBC sport suspensioned C3) the tires used and the shock valving, all of which can dramatically changes the ride and steering/Handling.

The 81/82 base suspension C3's are, frankly, marsh mellows with VERY soft spring rates versus all the other years with a rear composite spring rate of less<200lbs (192 lbs) as well as very low rated coils up front..

 

Thanks for the info. Would seem to me if it has to do with up and down that you can feel in your butt maybe rubber would be the call, if it has to do with lateral movement and stability poly would be good.

 

if you drive on the street,,use rubber,

 

Last call for me, POLY DOES NOT SIGNIFICANTLY deteriorate the ride on the street.

For those that insist on stating poly worsens the ride versus rubber control arm bushings on the street, do you have poly control arm bushings on your current C3 and did you have rubber prior to the conversion? Another words, do you have real world experience with both materials on your C3? Just curious......

 

jb,
I do and I have real world experience with both. On my last complete suspension rebuild (for my '73) I used Prothane Motion Control poly bushings for the entire car, including all the differential mounts , which often get overlooked. Just for clarity, I'm not a backyard mechanic. I spent many years with GM as a heavy line tech and have a list of GM certifications as long as my arm. That being said, driving a C3 with rubber or poly bushings I can feel no difference at all between the two under normal driving conditions and I don't think most drivers would know the difference either. Other than the pronounced squeak issue with this particular car, I had not had a negative experience with poly before. I don't know why some poly bushings tend to squeak and some don't. Except for the squeak, the car drove and handled just fine. I have seen others who've posted pics here showing early deterioration of poly bushings, but I have not experienced that either. Due to their stiffer composition the poly can be a little stiffer to work with in places like rear control arm bushings, so I find rubber much easier to use there.
Again, in my personal experience, both will do the job with no real noticeable difference in ride comfort.
Cheers, Greg
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Thank You so much for supporting what I have said on this subject for years. I just get annoyed when others comment who may not have real world experience like us!

 

Thanks for the info.. So it seems that there is no real reason to go to the extra expence and trouble to use poly bushings.

 

I found a big difference in steering feel and handling, not ride quality. I think you should go with rubber...............based on you questions and comments

 

Your quote: " That being said, driving a C3 with rubber or poly bushings I can feel no difference at all between the two under normal driving conditions and I don't think most drivers would know the difference either. Other than the pronounced squeak issue with this particular car, I had not had a negative experience with poly before. "

 

I certainly noticed a difference, but I was going from worn out rubber bushings to fresh poly bushings. I see no reason not to use poly nearly everywhere, or del-alum, or even heim joints in the strut rods. The car handled much better after the changes. I also improved the alignment, steering, and stiffened up all springs, etc. It's a whole new car, really. The poly bushings contributed, but they aren't the whole story.

That said, I think @jb78L-82 is correct. The marshmallow feeling of the later C3s, especially 81-82, is mostly due to softer springs and corresponding shocks. Other things contribute to the perception of harshness in early cars, like the thicker frame in earlier cars, aluminum vs. rubber body mounts, availability of high-compression engines and big blocks, more common manual transmissions, uncomfortable seats, austere interiors, etc. but the suspension is the key.

I'd think it would be much easier to make a poly/solid bushed car handle like a marshmallow with a few spring/shock changes, than it would be to make a rubber bushed car handle well on the track. And even when you aren't on the track, better bushings (where appropriate), will limit camber change in turns, and other effects. You might never notice on 15" wheels, though.

 

Like I said, the OP would probably best be suited for rubber everywhere.......

Poly will definitely help the steering feel and handling by decreasing unwanted control arm movement with no ride degradation versus rubber but to each his own...............

 

I believe the poly/delrin/solid bushings help the most when you are past the 80% point in a corner. The steering stays crisp and responsive to small changes. A rubber bushed car at the same speed is more "jerky" and "unsure" and "snappy". On the track, at 9/10s and 10/10s and 11/10s you want small changes in the steering wheel to "talk" to you.
At normal speeds it matters much less.