Symptoms of bad LCAs?

[Racer Boy]

I'm skeptical that the LCAs are the cause of your vibration. I'd check what the previous posters mentioned, the wheels and wheel bearings. It is possible that the control arms are the cause of the vibration if they are completely shot, but I think you'd feel clunking and slop in the steering besides vibration. How many miles are on the car?

Why didn't you replace the LCAs when you replaced everything else? You will need an alignment after you replace the control arms, BTW.

[speedyspaghetti]

Originally Posted by Racer Boy

I'm skeptical that the LCAs are the cause of your vibration. I'd check what the previous posters mentioned, the wheels and wheel bearings. It is possible that the control arms are the cause of the vibration if they are completely shot, but I think you'd feel clunking and slop in the steering besides vibration. How many miles are on the car?

Why didn't you replace the LCAs when you replaced everything else? You will need an alignment after you replace the control arms, BTW.

There is some slop in the steering as well - it's not as bad as before I did the other things, but still present. The car has 86k miles. I didn't do the LCAs because I figured I could do the fronts without needing an alignment - there are no eccentric bolts on the fronts.

[hgsmith]

Force balance tires.

[mikefocke]

When the wheels were on the balancing machine did anyone test them to see if the actual rim was bent? I once found my wife's car with three bent rims (non Porsche but they were alloys). Spin at low speeds and hold a stick in a constant position relative to the edge of the rim and see if there is any variation. I was amazed there was no crack or other obvious deformity but they were definitely wobbling.

[SC-986]

I had vibration as well at speeds of 70mph or above; however no slop in the steering. Had the wheels road force balanced and the vibration remained. Replaced all (4) LCA's and the vibration was gone. Apparently the bushings or ball joints had deteriorated enough to cause the vibration without any noticeable clunking. I then upgraded to the RoW M030 suspension and it felt like a brand new car.