thomas.rousseau

Anyone having experienced problems with the big front (A-shaped) control arm rubber bushings.
I'm going to change inner steering ball joints and while I'm at it I might take the opportunity to do some more.

Can the bushings even be changed or must the whole control arm be changed?

/Thomas

Geoffrey

You need to purchase the entire control arm since the bushings themselves are not available through Porsche. You can get either the stock 993 arm or the 993RS arm which has stiffer bushings. Aftermarket monoballs are also available, however, I don't think you would want that for a street car.

Jean

I agree with Geoffrey, if you are buying new ones, make sure you get the 993 RS at once, I think they are the same price as well but even if they are not.

AndyT

i did the ERP monoballs , like geoffrey said, no good for the street.

Felix

PowerFlex makes replacement bushes; have a look at http://www.powerflex.co.uk/products....0&submit1.y=10

chris walrod

While I still owe you guys and gals a DIY write-up, I have replaced these bushings with great results. If you notice the first image has cracks starting in the bushing, circled in red. This is from a 37K mile 1997 993.

This car exhibited front tire shake indicating a front tire imbalance, which is the sole reason we started to look closer at other potential causes. After the install, the front tire shaking went away. Yeah!

I personally feel these ‘dual-mode’ rubber bushings are just too compliant, event for a street car. I realize Porsche did this for reasons of softening the car to appeal to an ever changing clientele, but if you think about it, bushing compliancy in this axis (direction) must allow all kinds of dynamic front end geometry changes, especially while on the brakes!!

Anyhow, some images:
Second image is of the one piece forward bushing being driven out
Third image -- aft bushings, they are two piece
Fourth image -- new bushing kit

Geoffrey

Which bushing kit is that? What are the bushings made from? I have found in other applications that the polygraphite bushings wear out rather quickly so I don't consider them to be a viable solution for a street driven car.

PS, if you make a mixture of grease and silver antisieze and put it on the poly bushings, they won't make noise.

Red rooster

As the driving force behind those particular Powerflex bushes I can say that the motive was two fold .
Tighten the front end geometry and make the replacement arms look like the silly price they are.
The 964RS /993RS versions of the standard arms have the REAR bush made slightly harder . The front movement control bushes are the same as all other 964/993 . That makes using the RS arms a very minor improvement.

I have been running the Poly bushed arms for three years + with no wear issues showing so far .

Powerflex have a web site that explains all .

Geoff

--------------------------------------------------------------------------------
KS400200 , the oldest 964 on Rennlist , unless you know differently !

chris walrod

The bushings are 95 durometer black urethane.

thomas.rousseau

Are the bushings from Powerflex?

Any drawbacks with them? Noise, squeeks, shaking?

You used a saw to take the old bushings out of the control arm?

/Thomas

chris walrod

This particular kit is from Powerflex. Fit was good.

Yes, removing the old bushing are quite a bit of work using a multitude of methods, one of which is using a holesaw to remove the center section before being able to remove the outer shell.

911/Q45

I remember using a propane torch to burn out the rubber bushings on my Corvette, would that work with a aluminum piece?

JasonAndreas

Chris, (or actually I guess anyone)
Have you ever come across Torlon 4435 at work?

chris walrod

Nylatron, but no experience with Torlon.

Jean

Geoff , The front control arms are different on the 993RS than on the other 993.
993 341 018 80

Thomas, just as another reference, the race shop where I took my car for suspension upgrade changed all the arms for RS arms where applicable, upon my request no hard bushings except for the metal GT2 subframe mounts. My car is quite competitive on the track.

Due to the cost involved in changing everything, I obviously mentioned replacing the rubber bushings only to some of these bushings, the answer was simply "not an option". I am not saying he is the voice of the truth, but his credentials as a Supercup lead mechanic are solid.

My guess is that these are ok to use on a street car, but I would not on a car seeing track usage, the other thing is that probably the replacement cost and frequency of changes might not justify it.