Subaru Legacy Forums

Subaru Legacy Forums (
-   Transmissions (
-   -   Suspected blown rear diff, please advise (

Strabismo 02-04-2012 08:13 PM

Suspected blown rear diff, please advise
2006 Legacy GT
Manual Transmission
80 000 km

I have recently did a long drive with my car (1000 km in a day) and at the last 100 or so kms I have noticed a noise coming from under my car that wasn't there before.

The noise is like a humming/ gear groaning and is speed sensitive (definitely not rev sensitive). I can't pinpoint exactly where it is coming from from inside my car but it doesn't seem to be coming from the transmission as it would have made a noise through the shifter if it was the case.

There is no felt vibration. No vibration in the steering wheel either. The noise becomes very apparent as I drive at 60 km/h and up.

I have lifted the car and the CV joint boots are intact. There is also no apparent play in the wheel bearings.

I have drained the rear diff's oil and what came out was a very dark, almost black sludge. Is it normal for an LSD's oil to be this colour after 80 000 km or is it a clear sing that my rear diff is going?

Any advice is welcome. I still have a warranty but I am 200 km from the closest dealership and I have an extremely tight schedule at work right now so I cannot afford to go back and forth to and from the dealership multiple times. I will also need to drive another 1000 km soon and I really want to fix this problem before that.

Thanks in advance for any input.

compsurge 02-04-2012 09:20 PM

Most oil changes color over time and heat cycles.

Have you checked your tire pressure?

When does the sound occur: under acceleration only, light throttle, deceleration, in gear?

Strabismo 02-04-2012 10:12 PM

The noise is speed sensitive only. Hard acceleration doesn't seem to change the noise (except resulting speed change does). Putting the car in neutral and letting it cruise on its own momentum will not change the noise either.

Tire pressure was checked 2 weeks ago. I can check again just to be safe.

Max Capacity 02-05-2012 07:08 PM

Ride in the back seat while someone drives the car. See if you can hear the rear diff of wheel bearing ?

Strabismo 02-05-2012 07:44 PM

Tire pressure was very high due to drastic temperature chance since I last checked it (from -40 to 5 Celsius). I've set the pressure back to spec but it did not affect the noise.

Strabismo 02-09-2012 06:22 PM

Anyone experienced anything like this or might have an idea at all?

compsurge 02-09-2012 07:22 PM

Do you have a local shop that does free diagnosis? You could take it there and then drive to Subaru for repair.

All times are GMT -6. The time now is 03:57 AM.

vBulletin Optimisation provided by vB Optimise v2.6.3 (Lite) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.