Vintage Mustang Forums banner

1 - 3 of 3 Posts

·
Registered
Joined
·
467 Posts
Discussion Starter #1
Hi
What gear oil grade is better for my Top Loader trans, 85W-140 or 80W-90?
Thanks!
::
 

·
Registered
Joined
·
10,170 Posts
It's a little hot down there in Texas, I'd go with the 85W140 stuff. Get it in a synthetic, it's better.
 

·
Registered
Joined
·
9,844 Posts
The guy who rebuilt my toploader specifically told me NOT to use synthetic oil because it would get past the seals and the tranny would leak. I don't know if this is an old wive's tale or not, but I'm running non-synthetic 80W-90 gear lube in mine with no problems so far.
 
1 - 3 of 3 Posts
Top