Zenak

I have a modified 1999 FRC with pfadt coil overs.

I think the noise is in the right rear. I road course drive the car.

It started as a "tick... tick.. tick.." when driven slow. Kinda like a front CV noise would sound like at low speeds.
Seemed to get a bit faster with speed, but did not linear increase, meaning the speed got 2x faster.. the noise only got a bit faster.

After the 3rd day at Watkins Glenn, the noise changed. It was more a "whrrr... whrr..." noise and a bit louder.

Both sets of noises mentioned above seemed to either go away or fade after 35+ MPH. Today It didnt seem to make the noise at all unless I reallllllly listen for it over the exhaust note.

Physical inspection of the suspension = nothing. Pulling on wheel shows no play in the hub. No vibrations or feel from teh wheel driving that are out of ordinary! No play in the half shafts, eveything seemed tight and button up on inspection on the right rear of the car wheel/suspension.

One last point to mention is that the "whrr... whrr..." noise will happen louder (i think) after putting the car and backing up... but ONLY for about the first 5 feet. Then seems no different then when Im going foward.

Ok what is it? Im thinking maybe I flat spotted a small portion of the bearings on the right rear hub and thats why its not a constant noise but a "tick tick" or "whrr whrr" noise? Thoughts?

AU N EGL

Bearing would be my guess.

CHJ In Virginia

Thats a really tough one to analyze. If it was a bearing problem, the noise would increase at the same rate as speed. If you have access to a lift - raise the car up and remove rear wheels. Start car and put in gear, get under and listen carefully to isolate location. Use a stethoscope or do the long screw driver trick to listen to specific parts, locations. Have some one vary the engine - drive train speed till the noise stays constant and you should be able to locate the source.

fatbillybob

That's how I would do it but the backing up thing makes me suspect the parking brake.

Oh did you check carefully for the beginnings of hub crack?

longdaddy

exhaust leak?

Zenak

Hmm didnt even think to check the parking brake set up, I will have to do that. Thanks. I ordered a hub just in case to be safe, SKF. I losta hub a few weeks prior and one by one as each goes bad using SKF all around.

CP Thunder

Not to change your subject but I am wondering about the SKF hubs (I have all four already).......noting the design change and difference of flange thickness, would it be recommended to only change 'one at a time'? I think at minumum I would change 'pairs'..........

Zenak

pfadt said that its ok to do one at a time. im doing them as they go / afford it. this hobby is ridiculously expensive when you start tracking all season long.

billcar9999

I had similar problems on my car with sport shocks. The tick was really random. It turned out the spherical bearing on the left front shock was bad. I couldn't confirm it on the car. Once I got the shock out and compared it to the other, it was obvious. The good one was very tight. The bad one was very loose

I ran into the whrring noise after the first day at NJMP. It turned out to be both rear hubs.

You didn't mention the light thunk sound which could be a tick depending on where your ears were tuned. That happens when the top mount loosens up just a bit. Loosen it up, apply blue thread locker and tighten.