I am fixing to get into replacing my front suspension and am debateing whether to go with poly or rubber bushings. I have read several forums on this issue and don't know which way to go. I am not going to be doing a lot of hard cornering and the roads down here are fairly rough. I just want a good stable ride. what do you out there suggest and what are your experiences?

 

rough roads - rubber bushings .... 69VETT

 

I used poly when I replaced my bushings. I thought it would be better. Now after a couple years the bushings are squeaking a little. If you go poly you have to make sure to use red loc-tite on the control arm shaft bolts or they can walk back out. One of mine did and fortunately it happened as I was pulling into my driveway and no damage was done other than it scared the sh*t out of me.

I also went poly on the spring bolt cushions and one of the lower ones literaly crumbled and fell apart. I have no idea what could have caused that, but I replaced them with OEM rubber and they have been fine ever since.

If I ever replace the bushings in the front again I am going back to OEM rubber. There must have been a good reason GM chose that material over polyurethane.

 

if you want to boil it down to one thing the word would be deflection.

the difference between the two is the the rubber bushings when under cornering loads will deflect more than the poly, or in other words the the rubber bushing will compress under load from the cross bar or the bolts as the suspension travels more that the poly bushing due to the increased stiffeness of the poly over the rubber. This deflection can result in incremental suspension geometry changes ( which worsen as the rubber ages) that the poly bushing are less susceptible to. For the average daily driven car the new rubber busings will suffice and going from old to new you will still see an improvement. Though with the poly bushings the improvements in cornering will be enhanced because the deflection will be reduced over the rubber type bushiings. I used Poly graphite bushings ( the graphite acts as "self lubricating") and I haven't experience and squeaking and the old boy corners very nicely.

Bottom line is that upgradeing to the poly bushing is by no means a mod that is required to restore your suspension to like new condition, and given ytour stated postion on how you drive your car will not result in a noticable difference. Though the rough roads part could have your suspension sqeaking if you dont lube them right during installation. But having said that there are definate benefits with this mod making difference in the turns. This added stiffness while good for the front, is not necessarily great for the T/A's since their motion during normal suspension travel differs from the front control arms..

here is an image from PST to illustrate my point ( this is my vendor of choice for bushing for the last two cars but I am not trying to push them)



the reason GM went with rubber is availaility and cost. poly eurothane wasnt around untill later, and when it became available the cost is much higher

 

I agree rubber deflects, and Poly was not avaliable in the early days,
If your looking for extremely tight handing and silky smooth performance,
on good road surfaces go with Poly.

If you want a smooth Cadillack ride on rough roads, go with the rubber.
you can also mix and match depending upon location and use of the bushings.
I used Rubber in the A- arms and poly in the sway bars.
Dito... PST is a good Poly bushing ! I also have used them on several cars.
good Luck...69VETT

 

I'm mixing and matching as I go. My sway bar and front suspension will be poly. My pinion, body and rear leaf will be rubber to isolate driveline and road vibs.

 

I did poly on my 76 when I did a frame off.Handels real well with no squeeks.But one of my A-Arm bolts did back out and cut into inner fender while driving it on the highway.Should use locktite as said in earlier post.

 

I used rubber on everything - talk about a "new car" ride!

 

My .02

If you plan to auto-X and thats your plan with the Vette, then go poly and lube the shinola out of them and use red locktite. Installation is a piece of cake. Maintenance (if they squeek again over time) could be a real frickin' PITA

If you plan to drive it on the street and to shows -wherever, and wnant it to be maintenenace free, then go rubber. If you go rubber, use MOOG and I recommmend Rock Auto as a great source for the best pricing. I went rubber and dont have any regrets.

To install the rubber type, put the new bushings/boxes in your freezer in a plastic bag for a few days and take them out only when your ready for them. Lube the outside metal sleeve with engine assembly lube and use a large impact socket and an engineers hammer to drive them in. You absolutley dont need a press. Doing this method with resting the A-Arm on your vice, you dont have to worry about bending your A-arms like a press might do.

The pivot shaft needs to be in place when your doing this and should rotate relatively freely once the bushings are fully seated.

Its quite an easy job-once you get the old ones out. Use a hole saw and then a drill to hog out the old ones to get them to release easier.

B...

 

I replaced mine with poly a year ago and love them; no issues with squeeking. If you go poly, use marine lube between the bushings and metal where they pivot. The marine lube is more weather resistant.