Saab 9-7x with Limited Slip Differential problem.

[Rimrock Pete]

Hi, I have a problem where my 2007 Saab 97x rear differential is not slipping after it gets warm on long drives over 20 miles. It hops and thumps as I try to turn into parking spaces or backing out of them. It even has trouble turning into my driveway. I took the differential cover off and wiped out all the old black fluid and tried to buy GM 88862624 at a GM dealer parts counter but was told they did not have any. I was told they use Mobil 1. Maybe they did not use it in a LSD. Or maybe the parts guy was on LSD. Anyway, the Mobil 1 made it worse. Should I buy the ridiculously expensive GM fluid somewhere or will an additional additive to the Mobil 1 help the clutches from sticking? This is only a rear differential binding. Thanks for your help.

 

[HARDTRAILZ]

I would change the fluid again if it was really dirty. Could still have some gunk in it. Did you inspect the spders n such really well and clean it out when you changed the fluid. I just use brakekleen and a rag to clean up and ensure the magnets are clear.

I would not worry about the GM fluid but would use Mobil 1 again. it has a great reputation and is GM approved I think.

.

 

[Rimrock Pete]

Thanks, I just wiped it out. I didn't know what to expect or inspect.

 

[djthumper]

I would likely drain it and take look at it closer.

 

[AWD V8]

I just use 75-90W with the GM additive.

Without the additive the diff can stay locked and not unlock easily after it has engaged.

 

[Rimrock Pete]

It appears that I am going to take the cover off the differential, wipe it clean and then really spray what I think looks like they might be the clutches with brake cleaner. Once it evaporates, replace the cover and add a good quality additive made for LS and then fill the remaining capacity with Mobil 1 "Synthetic Gear Lubricant LS 75W-90". Does this sound right? Is it the right sequence? Thanks!

 

[smitty5150]

Is your saab awd? Are you sure is not the transfer case staying engaged?

 

[Rimrock Pete]

Hello, I originally thought that it was my automatic AWD motor on the side of the transfer case. When I have my driver's side window down, I hear a little beep on a very regular sequence such as every 35 seconds (I can't remember exactly how many seconds but no more than 60) that sounds like it is coming from the middle of my vehicle underneath. I gave up on that idea because the front wheels do not act as if they are engaged at all when I have the problem. If I shift into neutral and roll along, I still have the turning problem in the rear of the vehicle only. The rear universal joint feels absolutely tight. Thanks.

 

[Mooseman]

I think all you need to do is remove the fill plug, suck a little of the oil out and add the limited slip additive and top off the oil. It probably just needed a change but you omitted to add the additive.

If you've never done the transfer case, do it now! Even if it doesn't engage on a regular basis, you still need to change it every 50k miles. Might as well do the front diff too.

 

[HARDTRAILZ]

Open it up and take pics and post if you see anything odd. We are here to help!