[enkeivette]

Why not run solid needle bearing suspension bushings? As opposed to rubber or urethane. From a racing perspective, not comfort.

[Vettezuki]

Originally Posted by enkeivette

Why not run solid needle bearing suspension bushings? As opposed to rubber or urethane. From a racing perspective, not comfort.

Mmm, pliable bushings add to suspension compliance. This can manifest as unpredictable weight transfers (bad) or bits and pieces NOT breaking because there's a little give (good). As far as I know, most street car based race cars use metal spherical bushings as much as a possible and essentially no rubber.

I'm running solid trailing arm bushings in the Vette (stock is rubber) and the difference in how the rear-end feels under harder cornering is noticable, however, the comfort is not that comprised. Obviously metal must be VERY thoroughly lubed it won't last long at all.

There, how's that for not answering your question?

[enkeivette]

If u joints can stay lubed up and functioning properly for 30 years at the RPM that they see, I'm sure it wouldn't be a problem for suspension. Although, the needle bearings would have to be a lot thicker to handle the weight.

I keep accidentally hitting Edit on the last post instead of Reply.

[Vettezuki]

Originally Posted by enkeivette

If u joints can stay lubed up and functioning properly for 30 years at the RPM that they see, I'm sure it wouldn't be a problem for suspension. Although, the needle bearings would have to be a lot thicker to handle the weight.

Remember the bushings are rotating metal against metal. U-Joints are for connecting driveline components at different angles, there's not much "grinding" is there? My TA bushing is spherical metal against metal; the bushing rotates in the the stationary sleeve. No lube es no bueno.

I keep accidentally hitting Edit on the last post instead of Reply.

Don't do that.

[enkeivette]

Guess I won't be making any trips to the patent office.

[big2bird]

Originally Posted by enkeivette

Why not run solid needle bearing suspension bushings? As opposed to rubber or urethane. From a racing perspective, not comfort.

You would encounter brinelling. U-joints have a back and forth motion that keeps them lubed.
Herb Adams used to make Delrin susp. bushings, then when he died, his son did for awhile.
The problems with poly is the action. Pressed in bubber bushings actually torque, or twist. When you install poly, they move rotationally, introducing wear on a shaft point not designed for that action.
IF your setting up for full race only, solid bushings, heim joints, Johnny Joints and the such would be ideal. If your going to drive it on the street, with alot of maintenence, it would be fine. DD? No way.

[94cobra69ss396]

A lot of the offroad racing trucks use heims because rubber or poly just doesn't last. Our buddy use to race a class 8 F150 and he used poly bushing in the trailing arms. We had to replace them during the race because half way through they would already be worn out or missing.

[TimAT]

One of the problems with Poly in the front control arms- they like to work the bolts out and disappear. I put all poly in Ol' Red, but the front ones I cut grooves in the ID and then drilled them and installed zerks so I could lube them if I needed to. Then used loctite on all the bolts. So far, so good.

[big2bird]

Originally Posted by 94cobra69ss396

A lot of the offroad racing trucks use heims because rubber or poly just doesn't last. Our buddy use to race a class 8 F150 and he used poly bushing in the trailing arms. We had to replace them during the race because half way through they would already be worn out or missing.

Poly, like rubber, is available in different grades of hardness./commpliance.

[94cobra69ss396]

Originally Posted by big2bird

Poly, like rubber, is available in different grades of hardness./commpliance.

These were on the radias arms and it was the front ones that always went bad. But you also you to realize this was a truck with a 600hp big block that was doing 40-120 across the desert and spending a lot of time in the air. The front bushings in the radias arms took a pounding. Even trucks that run heim joints have to replace them often because of the stress that they endure.