Dave951M

I'm finishing up boxing the control arms on my 931 and would like to use urethane bushings rather than stock. Haven't found any for the 924/31 series, so, if the arm is really a VW part that also crosses to the early 944na, Wouldn't a set of bushings for the VW also fit? If so, from what model? Tried searching the archive this morning and that's where I got the info about a Jetta arm being the same as the early 944. The 931 is supposed to be the same arm, so why wouldn't a Jetta part fit?

Dave951M

BUMP

Matt

Dave,

It's the same arm as the early Rabbit, through at least '84. There are a number of aftermarket bushings available, just make sure that the ones you select for the front (the round ones that locate the arm in the crossmember) have a metal sleeve throught the center. The sleeve is essential. Some bushings are just plastic without the sleeve, and are trouble. Prothane sent me a set of their Rabbit bushings, which have well made sleeves, to track test several years ago and they worked very well.

The bushing material itself has to have at least a little flexibility to accomodate caster adjustment, otherwise the bushing will be put into bind and will fail.

Matt

M758

Also check out paragron products. They have some for the early arms. Get the red colored ones. These will work better than than the old blacks.

I use these on my race car and would never go back to rubber.

Skip

Just confirming that the new Weltmeister bushings we now carry do fit the 924 also.

Danno

How about some Delrin bushings? Urethane tends to cold-flow and you end up with an oblong hole after a while...

Skip

Been meaning to gauge interest in that - I can't think of a good reason not to try it.

Any interest?

M758

Sounds intersting

Manning

Yeah, that does sound interesting. I think Shine Racing Services will make sets for these apps. I know they definitely do for VWs.

Wondering about poly though. Danno mentioned cold flow. I know I have also seen poly, in this and other applications, basically shred under load. One non-automobile example I recall was the tendency for the poly "springs" to develop radial cracks and shred in early mtn bike suspension forks.

Also, why don't folks just make higher durometer rubber bushings? I am pretty sure the Porsche factory used these in some earlier race cars.

Also, what is the difference between the durometer of factory rubber bushings versus typical poly bushings? And does the rating for poly vary widely between manufacturers?

Skip

I think you could refer to the new red Poly-Impregnated rubber bushings from Weltmeister as simply a higher durometer rubber... with Poly added for durability.

Delrin is clearly a better choice for racers who want the near metal bushing ride, without the cost and possibility of increased maintenance. Though in some suspension applications Delrin is not a good choice because it does not allow the imprecise movement needed as a function of the suspension geometry. Delrin use in the sway bar end mounts and other areas must be carefully monitored to ensure no collateral damage is caused. Control arm bushings *should_be* just fine with this material, as their movement can and should be quite precise (front and rear points are linear)