Control arms, etc. for 85.5

[djnolan]

For the 85.5 944 it looks like it has the old style steel control arms. I have some clunking noises so I figure it is due for a control arm rebuild, bushings, ball joints, etc.

I occasionally hear reference to an upgrade to later model control arms. But I see the bushings and ball joints for the pre 85.5 models are downright affordable.

What is the benefit to upgrading to the later model control arms and what is involved other than changing the control arm assembly?

Thanks!

[Stephen03]

There is no benefit except it looks cool.

[9FF]

There is no benefit except it looks cool.

There's a bit more to it than that. If you have stock steel and don't intend to upgrade the suspension or track the car, then replace with stock steel arms. They are cheap and the ball joints are easily replaced.

If you plan on tracking the car or upgrading the suspension substantially you should consider buying either "boxed" (strengthened) steel arms or fitting the later aluminum arms. Reason: the steel arms have two week points, at the sway bar mount and at the rear castor block mount. The "boxed" steel arms will allow you to fit a larger sway without fear of the mount failing. The aluminum arms are already strengthened at the sway bar mount and they can also accommodate the stiffer and better 968 castor block at the rear. The aluminum arms are much more expensive though and the ball joints are more difficult to replace.

Your choice, cheap and weak, cheap and a little stronger or expensive and stronger still.

[FrenchToast]

Looking at your signature you have an 85.5, which would've come delivered with aluminum arms. If they're currently steel, somewhere along the line they were replaced.

For track use, I always recommend aftermarket arms, as both the aluminum and steel ones have their weaknesses.

Take care!

[Capt Squid]

A good portion of the 944 Spec racers with early cars through 85.5 run stock steel A arms as opposed to the aluminum ones. Most of us run a 28mm Weltmeister swaybar with no problems. The steel arms are cheap as are the replaceable ball joints. I usually change out the arms every two years and the ball joints every season. If I have a front impact, I change the arm and ball joint.

Our SoCal racing group does not box the arms. The reasoning for this is that the arm acts as a crush zone during impact. I checked with the engineer next door who designs and builds aircraft landing gear about boxing the arms. He said it would not stop the flex to any significant degree. He did say that the aluminum arms would have less flex.

One of our group has had two sets of rebuilt aluminum arms have the aftermarket ball joints loosen up. He switched to the steel arms and now has no problems.

[Rasta Monsta]

+1 Squid, -1 FF.

Steel arms are fine, many many people race on them every weekend after simply welding the seams.

[djnolan]

Yes, they are aluminum after all. My mistake. Should have looked before posting.