Have a 77 f150 4x4 and was wondering what weight in syn. Oil people are running in there manuel trans, tranfer case, and difs?

 

Don't take my exact word on this. If you have something like a T-18, you probably would need a 90 weight in the transmission (I don't know what they take for SURE, but my NP435 calls for that). You'll need to check your manual... or wait for someone that knows.

But, if it calls for 80W-90, you can use a 75W-90 synthetic. Redline MT-90 would be my choice. I don't know what rear end you have, but I'd guess a 9" rear. They call for 75W-140, I believe, especially if you are going to tow with it. But, I think 75W-90 is 'ok' for the 9" if you just ride around with it as a grocery getter. Personally, I'd put 75W-140 in the 9".

 

I am wondering the same thing, if anyone knows what oil weight to run in an NP 205 xfer case and NP 435 trans? I've seen everything from 10W-30 all the way up to 90W. Any thoughts?