Control Arm Blues

[RandallNeighbour]

Both my mechanic and a different shop owner have told me they rountinely replace the lower control arms on the front ends of our cars and 996's (which are the same).

Apparently, Porsche gave the part to a low bidder who did a lousy job of selecting the grease-filled bushings and they dry out or leak quite quickly.

I had a new control arm put in the front driver's side 18 months ago and it has now gone out in less than 10k miles. The part alone is $265, plus a couple hours of labor.

Has anyone else had control arms go bad on them "prematurely" or repeatedly? How many miles should I be getting out of a control arm, anyway?

In all my other cars, I have NEVER replaced a control arm, even when I've put far more miles on the car. (BTW, I have not done any suspension work to the car—it's all factory.)

Which leads me to ask yet another question... could a worn strut cause a control arm to wear rapidly? My mechanic says my front struts are fine and not to replace them yet, but I have 94k on the car and if I'm going to have the control arm replaced, should I go ahead and have the front struts done while I am at it just to be on the safe side?

Any input, even theory or conjecture would be appreciated.

[KRZTACO]

Hi Randall,

Interesting situation.....I have never heard about something like that.

Instead of replacing with an OEM control arm....particularly after you've replaced two....have you looked into a performance or racing application control arm that includes hiem joints/greasable zerk fitted bushings, etc.?

If you've looked into it, how much do they cost, etc.?


KRZ

[insite]

i THINK (correct me if i'm wrong) that randall's referring to the ball joint. unfortunately, the boot is manufactured as a part of the control arm and is not replaceable. the joints dry out and start to knock. i think this can happen more quickly if the car is lowered, as the ball joint angle is more severe under normal driving conditions.

it would be nice if there were an aftermarket supplier who manufactured a ball / boot that could be pressed into the control arms, but at this point, there aren't any.

Randall - what are your symptoms? 10K miles indicates some other problem (or a mechanic that tore the boot on installation of your part). these should last at least 80K miles. worn struts won't accelerate wear on your control arms. also, FYI, the control arms that wear most commonly are the rear uppers. the bushings wear and begin to knock slightly when you hit bumps.

[RandallNeighbour]

Actually, the bushings and seals can be opened, repacked and closed again, but Porsche doesn't recommend this... they'd make no money doing that.

The shop that said they replace them all the time is a race-specific shop. My car was one of the only non race-dedicated Porsches in the shop at the time. I do not believe they use race-designed control arms on our cars as of yet. I could be all wrong on that, but if they did have better ones I am sure he'd have told me about them to sell me a pair... this shop owner is a sharp business man.

[RandallNeighbour]

Insite, in both instances, it has been steel on aluminum sqeaking coming from where one part seats into the ball joint and that's what goes. Here's a pic of what I have to replace:

[AUDIOGUY]

Just curious, why did you have to replace them again? Was the car pulling or not able to take an alignment. I was wondering if my ball joints are worn... I feel like my front end has too much play in it. When I hit some bumps here and there, the wheel shudders or the car bump steers. I dont think I have a bad strut, but I havent inspected them. Unfortunately, you cant just replace the ball joint.
Any insight?

[insite]

the ball joint is made of steel and the control arm is made of aluminum. between the two, there is a nylon bushing that prevents squeaking. it wears out and the arm squeaks like crazy.

randall - with regard to race-bread versions, the GT3 control arms are race-specific, but i don't think the ball joints are different (just the mounting point / shimmable length).