2002 AR - Rear Diff Grinding, 75W85 to blame?

[YKallroad]

The shop put in 75W85 where the manual calls for 75W90. I had said I would be using the car in extreme cold so I think they thought this would be the lightest weight I could get away with. I now have grinding at slow speeds in tight corners.

Anyone else ever experience this?

[Jay's Euro]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Not to say for sure, but if it is ever since you changed the gear oil then most likely, any difference is viscosity can make this happen, has to do with how the oil shears. Even the difference between synthetic and non-synthetic gear oil(any oil for that matter). Its the reason why manufactures really push for you to use a certain weight oil or even their own because of the slight differences in composition and standards that are ever increasing.

2nd year technician apprentice, ^just from what I know.

[YKallroad]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Thanks for that. I'm going to head to Princess Auto to see if they have a 17mm hex I can pick up to do another change it fill it with the proper weight gear oil.

[BaggedGLI]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Princess auto should have it otherwise give your local Mac tools/snap on truck a call.

[onceover]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Are you sure its not the automatic diff locking up?

[Jay's Euro]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Also it might be the matter of adding a friction modifier to the gear oil, think it might be for limited slip-difs but it may be all difs, just check on that one

[PRY4SNO]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

I'd just take it back so it's on record that they botched the job. What happens if you experience a related failure, down the road... literally and/or figuratively?

[YKallroad]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Automatic diff?

[YKallroad]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

This occurred after they changed the seals in the diff (they were leaking.) The suspension was also changed over to conventional vs air strut setup. So a couple of factors might be at play. I'll call them tomorrow, they say the work is warrantied.

[YKallroad]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Took Rob at Westside in Edmonton for a ride. He says the noise I'm hearing is normal. His A4 Avant makes the same noise at low speed, full lock. New tires I installed have exacerbated it (didn't hear it on the winter tires.)

[morris400]

Re: 2002 AR - Rear Diff Grinding, 75W85 to blame?

Lol.....westside.