Ring and Pinion Failure?

[Jrboulder]

Greetings pelicans,

I finally get my 84 944 running great and now I think the r&p is on it's way out. On deceleration it makes a grinding noise when it passes 3800 RPM. Is this a sign of the ring and pinion failing or is this something else.?

Thanks!

Jackson
1984 944

[John_AZ]

Great work so far.

Disconnect the rear coupler that attaches the TT (torque tube) and the transaxle. Use a very good quality/expensive metric hex---do not strip the coupler bolts!

Slide the coupler back ---towards the transaxle.

Start the car and try to get the same noise. If you get the same noise/vibration, the TT bearings are shot----common. 4 bearings and a lot of work or get a rebuilt.

If no noise, fluid should be drained. If you want to save it, get a clean bucket and filter the oil with a nylon stocking or similiar. Check for metal slivers.

Open up the inspection plate on the transaxle on the PAX side. Remove axle and CV. There is a bolt in the center of the axle hub on the transaxle. Remove the 12 or so bolts around the inspection plate. Check for damage.

GL
John

[Cocacolakidd]

Bearing noise can be allot of different things going wrong - The first thing that comes to mind is a faulty Clutch Throw Out Bearing, but that noise usually is in the front rather than the rear of the car. Input Shaft Bearing, Synchros on on one of the 2nd or 3rd gears, and also the Ring and Pinion.

What does the sound do if when de-accelerating and noisy if you clutch and put the gears into neutral - does this stop the noise, or does the noise continue while coasting in neutral ??

Also and first is to check the 90W fluid level in the Transaxle - low on fluid will also cause noise.

[Jrboulder]

Thanks for your help!

It doesn't make any noise in neutral. I am not that disappointed that it is making noise because now I can put an LSD box in it. I will take the side cover off this weekend. I changed the fluid three months ago. I have a gallon of swepco 203. Should I use it I'm my box?

[John_AZ]

Disconnecting the coupler, isolates the transaxle.

With the coupler disconnected, rev it to 3800 and check for the noise.

Repeating, if you hear the noise at 3800rpm====maybe the TT bearings are shot.

If you do not hear the noise, transaxle may be problem.

Make sure you check you transaxle mounts, muffler & exhaust, and shock mounts to torque spec.

GL
John

[phoenix_iii]

I had the rollers (U/O) installed in reverse by a bad shop. Wicked vibration just around the ~4000rpm mark... Did you just do belts and rollers? Smooth and fine from 0-~3800, ~4300-end.