Straight 90 Weight Synthetic Gear Oil

[76FJ40]

I'm trying to find straight 90 weight (not 75-90 or 80-90) synthetic for the rear diff in my wife's FJC without any luck. I've checked Mobil, Amsoil, etc. without success. Any suggestions?

 

[Cruiser804]

Why do you need straight 90w? 75w-90 should work fine and meets the manufacture specs.

Search the forum there are many articles on this subject. I recently went through the same search.

 

[76FJ40]

The Owners Manual calls for 90 weight above 0 degrees and 80-90 for below zero. With this spec, I don't want to use 75-90. I'm towing a trailer with the FJC so I'm leary of going with a lighter than specified gear oil.

 

[Cruiser804]

I could have misread this informaiton but I think the 75w means that this is the thinkest it will be and 90 means the thinest it will be at operating temp.


http://auto.howstuffworks.com/question164.htm