I've been trying to find out all I can about the proper GL-5 75W90 oil to put into my soob and I've come to the conclusion that SP MTL-R is what I'm going to try. Do I run any potential harmful risks to my MT or AWD by changing the oil at 118k miles? I do not believe that the factory oil has ever been changed. Now my question is, do I need to "flush" the transaxle before I fill it with the new fluid? Is simply warming it up and draining, then refilling enough?

 

Any help would be appreciated,

 

Thanks

No need for a flush. When replacing just clean the magnet on the drain plug. You should notice a buildup up dark gray material on the magnet. As long as it's just a molasses type buildup, you should be fine. It you find any larger pieces of metal there, I would look further. But if you have no problems and are just changing it for maintainence, then you should be fine.

Manual trannys don't have the small pressure passages and valves which are so critical to an automatic to it's operation.

ALSO cover the Y pipe just below the drain. It will get the used gear oil on it, and stink for quite a while.

No need to flush it out. Just make sure you've driven it for a few miles to get the fluid hot so it drains out easier, and is more likely to take contaminants with it.