I'm currently rebuilding a spare 10 bolt I picked up and while boxing the LCA and Panhard bar I'm thinking of just replacing the buchings while they are off the car. I've heard some people say they prefer rubber to polly buchings so I was wondering what the advantages/disadvantages were of each and which people generally prefer. I don't want the car to squeak too much when going over bumps.

Thanks,

Robert

 

I have all poly bushings in the rear suspension, and it eliminated the noise my swaybar bushings were making when I went over bumps, when those bushings were installed. I don't have any squeaking from any of my poly bushings.
You won't gain anything by boxing up the LCA's and PHB, and just leaving the stock rubber bushings in place.

 

Well, when I had double poly ended LCAs, they would bind in hard cornering.

 

I've heard of them binding. What effect did this have on the car and how did it feel when driving it?

 

The bind is caused by the LCAs not being able to work as they are designed to. The rear of the car moves over the rear axle (imagine the axle as fixed and the body as mobile). When the car enters the turn, the body tries to move to the outside of the turn due to momentum, while the axle tries to remain in place (you hope). Now, if taken from a helicopter view, this motion has an effect on the suspension linkages. The most apparent is in the LCAs. As the body moves over the axle, the LCAs are put into stress (bind). The factory rubber bushings allowed for this by flexing and allowing the energy of the movement to be absorbed and dissipated easily. Polyurethane is stiffer than the rubber, and doesn't allow this dissipation so to happen so nicely. They bind in the same was as the rubbers, but they will snap back into their original position when releaving the pressure instead of allowing it to be released smoothly like the rubber. The car can snap oversteer while your exiting the turn if you are cornering hard enough. I've had this happen to me on several occasions, and it's interesting to say the least. One choice is replacing the old bushings with new rubber ones. If you're looking for more flair, rod ends work well in the LCAs, but to some they are too harsh. I have a set of LCAs built from parts ordered from the circle track suppliers. It has heavy duty rubber bushing on the body and a rod end on the axle. Another nice option is the 3 Piece Poly-Ball Bushings found from Hotpart

 

I have heard of that issue with poly bushings, but I have not experienced it myself. Maybe different companies' poly bushings are made out of slightly different compounds?
I made my own poly bushings, maybe the material I used would cause them to act different than most of the aftermarket ones available?
Under normal driving conditions, there should be no trouble with poly bushings.

 

All poly in my car's suspension.

I run it almost as hard as my Vette in the turns and have never had any issues with them.

I have heard they sqeak a bit on some folks cars, but don't personally know anyone who's made theirs bind up.

 

It might have something to do with the compounds or the design of the arms. Or it might have something to do with the turns you take the car in. Mine doesn't do it in every turn. Or, you might not be generating the grip required to get them to bind. Nontheless, it happens, and mine's not the only experience I've heard of.