nick.cfrancis

I believe that the ring & pinion has failed in my 9U transaxle. The last transaxle fluid change was clean with no metal bits and I currently using Motul Gear 300 LS 75W-90 fluid.
The other possibility I considered is a failure of the torque tube bearings, however the sound appears to be coming from the transaxle.
I recorded a video of the horrible noises from under my 944. Can I get confirmation that this sounds like ring & pinion failure and not torque tube bearing failure?

Also, any leads on a turbo LSD transaxle including 9U, 5R, or AOR (I wish)?

Constantine

Hard to tell since the torque tube will carry sounds throughout the assemblies.

Best to just drop everything and inspect each component.

As for parts, Cogs Cogs, 944 Barn and Plyhammer are good places to start.

HTH.

nick.cfrancis

Rats! I was hopeful I could narrow down the failure point to start sourcing parts before tearing it apart.
I checked with Plyhammer and he doesn't have any LSD transaxles at the moment. I will reach out to Cog Cogs and 944 Barn to check stock tomorrow.
Black Sea R&D for torque tube bearings?
https://www.blackseard.com/site/inde...ducts&Itemid=3

ealoken

Easy to eliminate the Torquetube, slide the coupler all the way on the gearbox side, start up the engine again.
If the shatter is still there, Torquetube bearings.

Constantine

From my experiences over the years, this kind of noise issue is either a catastrophic failure of the TT bearings or transmission issues. Usually there will issues with both.

That's why I recommend dropping the assemblies and checking each thoroughly.

Imagine fixing one, putting it back together and the noise issues are still present. Happens more often than one would think.

Should add this approach will help focus on what items are truly needed than guessing what should be purchased before hand.

walfreyydo

Sounds like a bearing, possibly input shaft in trans (since its in neutral) or TT bearing

R&P isnt moving if the car is stationary like in the video, so you can eliminate that

Gage

I have more questions than answers from the video.
Is the transmission in gear during the video? If so, the axles are not turning which would indicate a major transaxle failure.
If the transmission is in neutral, the final drive is stationary so why would you expect a ring or pinion gear failure?
With the car on a lift, a competent 944 mechanic will be able to isolate the sound. Removing the driveshaft coupler is a good diagnostic suggestion.

nick.cfrancis

The transmission is not in gear during the video. Following a bit more research into how transaxles work, I now understand why this noise in neutral would not indicate a ring or pinion gear failure.
I will work on disconnecting the driveshaft coupler for additional diagnosis and post a new video.

nick.cfrancis

Ok! Thank you for the note on the R&P. I did a bit more research into how the R&P gear works in a transaxle and now I understand that I was wrong.

Oddjob

I'm not sure what I hear in the video. There's normally a lot of noise underneath a running car, and not clear what the phone is picking up.

Did it start making a lot of unusual noise while driving, or why is the car in the shop for service? Does it drive, or did something fail leaving you on the side of the road?

For sure don't buy anything until the problem(s) is correctly diagnosed.