Buick Encore viscous coupler fluid change

[cnason]

I have a 2013 Buick Encore that is a victim of the corroded rear differential. There is a GM technical bulletin about the corrosion causing leaks. Since mine is beyond warranty I am out of luck.
In the process of fixing it I got another one from the junk yard and it has a bad clutch assembly. Mine still has a good one ( or so I thought ). Upon taking it apart I discovered the inner seal for the clutch ( also called viscous coupler ) was leaking. I took it apart and cleaned it out. It doesn't smell burnt and all the clutch plates look good. I am trying to figure out what type of fluid I need to fill it back up and how much I need. From what I could find on line it looks like I need a silicone oil, but I am not sure what viscosity.

Any help would be appreciated.

 

[Again]

What kind of mileage? My dealer here is replacing them seems regardless of warranty because of a bulletin. Magnesium and salt apparently aren't best friends. Looked it up in the repair manual but they only show how to replace the clutch, no mention on how to repair it, yet they go into great detail on how to repair the transmission. Sorry! I've been spraying mine with oil every year since I've had it because I had heard of this possible problem.

 

[cnason]

What kind of mileage? My dealer here is replacing them seems regardless of warranty because of a bulletin. Magnesium and salt apparently aren't best friends. Looked it up in the repair manual but they only show how to replace the clutch, no mention on how to repair it, yet they go into great detail on how to repair the transmission. Sorry! I've been spraying mine with oil every year since I've had it because I had heard of this possible problem.

Thanks for the reply, I would have to run out to the garage to confirm but I am guessing 120k ish. And yes, I live in a northern state that uses salt on the roads. The diff I took out of the car is pretty bad, had a piece about the size of a baseball break off of the side....only thing holding it on was the zip tie from the wire harness.

I am going to call our local dealership on Tuesday.

FYI the service bulletin for the corrosion from GM is: #18-NA-049

My vehicle is out of warranty, but I took a boat load of pics before and after I pulled it so hopefully they do something about it...otherwise I am back to trying to make one good one out of the two.

 

[Again]

That clutch is like $500 at rockauto so I can just imagine what GM is asking.

 

[cnason]

Well I ended up calling my local dealer, they of course told me it was out of warranty so they wouldn't cover it. I asked about the clutch fluid and they had no idea. The parts guy called corporate who told him it is the same fluid as the rear diff....which it is not. The parts guy gave me a case number and basically said to put diff fluid in it and run it till it burns up. Then reference the case number and blame GM for telling me the wrong fluid. haha good enough for me...I am sure they won't honor it then, but at least by then I can have some more money saved up to buy another replacement one.

 

[Again]

Pretty sure the viscous joint is filled with a silicone type fluid up to 80% and some oil.
Silicone Oil 100,000 100000 Cst 500ml Viscous Coupling Silikonol T4 Syncro | eBay

 

[cnason]

Pretty sure the viscous joint is filled with a silicone type fluid up to 80% and some oil.
Silicone Oil 100,000 100000 Cst 500ml Viscous Coupling Silikonol T4 Syncro | eBay

Thanks for the link. The only equivalent stuff I have been able to find state side comes in 2-3 oz bottles for RC cars. I can't seem to find any larger bottles. I'm guessing half a liter would be enough but would rather have more than not enough.

 

[Again]

Maybe check with Mitsubishi they used the stuff in their viscous driveshaft on the RVR AWD