Strut Rod Bushings: Rubber or Polyurethane?
 

Got to replace the strut rod bushings. Not sure if I stay with rubber or go with polyurethane. Any thought?

I'm not sure as I never had any polyurethane bushings until just recently. I have heard a number of people say they'll crumble after a couple of years so I'm not completely sold on them.

Neither....

I have had stock strut rods with the OEM bushings, the stock strut rods with poly bushings (lasted over 20 years and still have them in the garage) and currently for the last 9-10 years Competition adjustable Heim jointed strut rods (no bushings at all) which are by far the best strut rod for a C3.

Why? One of the biggest weaknesses in the rear suspension of a C3 is the amount of suspension deflection (adverse camber change) that the stock strut rods allow in the IRS which effects the ride, steering response and handling. Competition adjustable Heim joint struts offer 3 advantages over the OEM type rubber bushing strut rods:

1. Much stronger than the stock OEM struts which will bend/flex under load
2. Eliminates the OEM camber bolt adjusting method in place of a fixed bolt system with adjustable length rods on the strut.
3. NO BUSHINGS to deflect under load and for even just cruising down the highway.

One of the cheapest and best upgrades to the rear suspension of a C3 is the competition adjustable struts with Heim joint endlinks. These struts made the rear end feel very solid, planted, and predictable under all driving conditions-These struts are superior to the alternative struts and not just if you race which I don't with my 78 but just in everyday driving. I have these:

http://www.mamotorworks.com/Corvette...d-kit-602910-1 BTW-the not recommended for street use comment from MidAmerica, I completely do not understand since the ride is hardly effected by these struts on my car...10 years experience now and others have commented the same over the years that use these strut rods

Poly bushings will allow for less flex in the rear suspension but the stock strut rod will also flex under load. My poly bushings lasted forever and are still in good shape but they did tend to squeak...

If its a street machine with standard tires, rubber/OEM style.

I installed Vette Brakes' poly adjustable strut rods. Stronger and infinitely more adjustable than the stock rods/rubber bushings. That was over 15 years ago. No squeaks and look/handle like new. That was before I went through the entire rear suspension (half shafts, trailing arms/bearing assemblies... all from Van Steel). The 9-leaf spring was replaced by a PO.

To compliment the VB&P rear struts, I went with their (at the time) TRW based, HD front rubber bushing/ball joints/idler arm/tie rods kit with the tie rods that have same adjustability as in back (but with rubber bushings).

The car handles exceptionally well with the KYB shocks and 255/60R15 rubber on all four corners.

Over 36k miles and over 18 years on my pair of $200 "poly adjustable strut rods" from VB&P and the rear suspension is nice and tight.

I went with poly bushing and they were shot after a few years and 8-10k miles. They distorted and were loose. I made up a Heim joint package and it has worked fine since. The MidAmerica kit for $200 is not outrageous.

Rubber or Heim joint.

:iagree:


Simple poly bushings aren't particularly well suited to linkage points which inherently move in 3D rather than rotating in a single plane.

My poly bushings lasted about 6 months before crumbling and falling out, I vote for rubber.

The material used today for Poly must be junk...The poly bushing OEM struts that I took out (installed by me in 1985) for the heim jointed struts in the 2006-07 timeframe were over 20 years old and looked brand new, as mentioned previously....:crazy:

I could reinstall them today if I wanted and they would still work as intended...now 30 years old....try that with rubber

Just curious, what brand were they?


Although I haven't purchased any poly bushings in a number of years, the Energy Suspension poly bushings I did purchase NEVER dried out or cracked over MANY years of use.

They were from Zip, no brand name on the packaging.

:iagree: Those are the ONLY two options I will sell.

If a customer brings me polyurethane adjustables...then that is their choice and I do not have to worry about a warranty. The current polyurethane seems to be failing a lot sooner than it should.

DUB

I went through two sets of new stock strut rods in four years due to poor quality rubber that tore and disintegrated. I don't know that it matters where you shop for something like a strut rod. I suppose most of them are made somewhere over seas and its the same manufacturer no matter which vendor you purchase them from...but perhaps I've had a bad experience.

I went with heim joint strut rods because I got tired of replacing the stock ones, and poly isn't the proper material for that application. I noticed an improvement in handling but no noticeable decrease in comfort or ride. I definitely recommend heim joint strut rods. Hope this helps.

MajD

I know this is an old thread, and maybe a left field question, but if rubber is better than poly in this situation, and adjustable is better than fixed, why doesnt any manufacturer make an adjustable strut rod with RUBBER bushings? Or why dont people purchase rubber bushings for their adjustable units?

Cast in point DUB. Like ACE said...THIS IS A VERY OLD THREAD, but since I just decided to replace my stock strut rods and go to heim joint, (which I should have done a long time ago) I thought this was appropriate to post this. I've had an issue with my strut rods that are poly. It all started when I put the DRs on and made hard launches. I guess the struts didn't like that and I could never get them to hold an adjustment and scratched my head a little since they weren't that old and poly. Thinking they were not bad and just a bad design when more power and tire bite was going on I decided recently to start the upgrade that has been sitting on the bench for the last 6-8 months now that I finally have the time to do it

I pulled off the worse side which was the drivers side. When I pulled the eccentric end out, this is what I found (see pic) I was shocked and then knew why it wouldn't hold an adjustment and the last time I launched my new motor hard the ass end wanted to walk a bit. You couldn't see it was gone from the backside installed with the bracket in the way. Keep in mind these struts are about 8 years old and poly, not rubber. It had crumbled to nothing and had a pile of crumbled poly lying in the bottom of the strut bracket. Even the struts look fairly new still. Surely these are made in china crap poly bushings.
https://cimg2.ibsrv.net/gimg/www.cor...ae06f5e5d7.jpg
All that was left when removed
https://cimg8.ibsrv.net/gimg/www.cor...4218128179.jpg
This is the same end, just the other side. So only one side was toast. The other end was fine on both sides, even the bushings looked new.

I didn't even pull the other side out yet since when I saw this I decided I wanted to make everything stronger instead of using a 1/2" bolt with a 5/8" heim wasn't going to cut it. I decided to use a spare 82 strut bracket and mod it to accommodate a 5/8" bolt on the eccentric end. Dropped everything off at my machinists shop today and I may have it back maybe next week if lucky, ready for maybe blasting the bracket, TIG the support brackets to ensure they are strong and then have it power coated. I'll post up the process pics as I do it. I guess this will just be another stock to heim upgrade, but a bit stronger in the long run I suspect. My machinist scratched his head a little and wondered why they only used a 1/2" bolt on the other end.

I just pulled out poly to put in some heims - not because of any problems but because I was doing a bunch of other work back there and had the parts available. My Energy Suspension poly bushes still looked like new after 3.5 years and over 40,000 hard street and track miles.

Same...my post #10...when I put on my heim jointed strut rods on 12 years ago, the poly bushings in my OEM strut rods that were over 20 years old at the time that I Installed in 1985 looked perfect. I still have them stored in the garage and now 30 years old look great. This constant drone that poly is junk is tiresome.

Poly is far superior to rubber in just about any application BUT because of junk poly now being produced and sold, the poly material has been tarnished. Lots of junk rubber and inferior foreign suspension parts for all cars out there too....Junk is junk..poly or rubber

Oem poly is no better.
 

Heres poly for you. HHR's used poly for bottom out bumpers and coil spring cushions. I was confussed by it at first. All 3 of my hhrs banged alot over bumps and I finally investigated hard on this. I found those black items disitegrated and needing replacement. They were like a sponge material and not like black rubber. Turns out it was closed cell polly pieces and not solid polly. And only the dealer had expensive replacenents for them. I was not impressed with how these all turned black and disintegrated on all 3 of my cars. So I got some rubber from the local gasket supply shop and made new rubber bumpers and pads. No more noise and no more poly. OEM or otherwise. There is just something unpredictably screw ball with poly and the industry is not being made to get to the bottom of it. I dont know if a bad recipe is to blame or if pollution in the environment makes them fall apart. But I did observe that the inside of the thick bumper was still intact as the outside was crumbling away. So there may be chemicals in the air thats attacking poly pieces.

I stand by my post #18...good poly is far superior to rubber in most applications. As I said before, junk is junk, does not matter, if poly or rubber.

BTW-the pollution 40 years ago was far worse than today, so I doubt the environment is causing inferior junk poly or rubber to deteriorate. Poor raw materials cause those failures.