Well, after about 3 years of reliable track operation I've finally had an issue come up this last weekend that forced me to put her on the trailer early. I had the orange 944 track car at Carolina Motorsports Park in SC this last weekend with Tar Heel Sports Car Club. Saturday was uneventful and fortunately a cloud cover most of the day kept the temps down. I did 4 track sessions with no issues.

I did a quick tech inspection on the car at the end of the day Saturday and didn't turn up any issues. Sunday morning first session I started to pick up a whining noise that about 15 minutes into the session got to be loud enough that I pulled into the pits. I wear double hearing protection while on track and the Supertrapp exhaust is pretty loud so diagnosing noises while on track is tough. Back in the pits I drove around enough to establish bad noises coming from the transaxle.

I put the rear of the car on jack stands and started the car in first gear. Modest clanking and banging coming from the rear. I stopped one rear wheel at a time (I don't have limited slip) with no change in the noise so that ruled out CV joints. The noise is coming from the transmission, not the differential, as far as I can tell. There is no noise with the car in neutral. 3rd and 4th really set up a racket. Convinced that I was done for the day, I drove it on the trailer.

I have a spare transaxle on my parts car. My first inclination is to bench test it some and if it seems sound, I'll swap this one in. Regardless, I'll break down the failed unit and report back as to what I find.

 

Sounds like R&P, you can take off the side plate off and look at it.