: Changed my differential fluid last night - pretty easy for those who want to DIY

12-21-11, 10:01 AM
I've been having the groan on the 1st few turns when cold like many others have had. That happened to me last year and the dealer changed the fluid under warranty (TSB) and solved the problem (but I'm not sure they used the new fluid specified by the TSB). Anyway when I mentioned it again this month the service advisor said that he might get it again under warranty but it is probably something you want to do every 12-15k miles anyway (esp. if tracking, which I am).

So I ordered the new fluid (5L to get cost down and cover me for several changes) that includes the additive (P/N 88862624) from GMPartsDirect and a suction gun from Amazon (http://www.amazon.com/gp/product/B004KEJXZA/ref=oh_o05_s00_i00_details) which is a PowerBuilt 648756.

Everything came yesterday so last night I decided to see if I could do it "real quick" without having to jack the car up. Turns out you can. I got under there & removed the fill then drain plug to let it empty into my drain pan. Then close up the drain plug & fill using the suction gun. It seemed to take more than the 1.1L the service manual said it should, but of course I made a bit of a mess letting some oil drip out of the gun which could account for that.

The hardest part was breaking the plugs loose since of course they were over-torqued (they should only be at 29lb-ft).

So actual job: 25 minutes. Cleaning up the mess: 30 minutes. Having a quiet diff: priceless.

I think next time I can do it faster & with less mess having learned a few lessons.

The PowerBuilt suction gun worked great and didn't leak as long as you keep the hose end elevated.

12-21-11, 10:16 AM
Good to know. That suction gun is now on my amazon wishlist so I don't forget the model. Thanks!

12-21-11, 12:39 PM
Good idea, nice of the dealer to offer that though. You might even get a new diff out of it if they do the TSB a few times.