Hi guys,

Im hearing a loud whining/howling noise coming from the rear of the car. While cruising at 70/75mph its very loud... Especially on acceleration. When i let off the gas the sound goes away but when i tap on it the sound comes back.

When i put her in neutral and coming to a stop the noise is even louder.

Im pretty sure its the rear diff but anybody know what may be the issue? Drivetrain has over 123k miles on it currently.

 

rear diff pinion bearing likely. Check for shavings in the drain plug magnet. if thats all its doing you might be lucky and be ok with just replacing the bearings on it. This is one reason TRE has the upgraded cover with the sightglass. It raises the capacity of the diff fluid to keep the bearing lubricated. Also, make sure to use OEM fluid only in it. I ruined this bearing using the wrong fluids in it.

 

Thanks! It's definitely coming from the rear and is very loud at high speeds.

I was looking at the TRE Cover Upgrade.... how do i order it? There is no option to purchase the cover on their site.

 

Agreed about the pinion bearing. Do you mind me asking what fluid you were using? (You can PM if you'd rather not shout it out).

Mine crapped out on me with OEM fluid, I've been using Motul Gear Competition (recommended by the shop who rebuilt my diff) since and have had no problems.

 

There are further steps you can do to verify it is indeed the rear diff. It just depends on how mechanically inclined you are. If you are able to raise the car, get underneath it, remove both rear axles, unbolt the prop shaft at the rear diff flange you can then freely rotate the rear diff. If it binds, doesnt spin freely,makes noises, then you know for certain thats it.

I would call Jon at TRE. Im sure he can sell you just the cover if you wish. You can send your diff out to him for servicing and just get it all done there. Just make sure you have a reputable shop/person do it.