rear differential
Senior User
Joined: Sep 2006
Posts: 282
Likes: 0
From: Broken Arrow
What year is it? Is it the original axle/diff? If so look at the axle code on the doorpost. If it is an open Diff 80w-90 will be just fine if it is a limited slip you will need to add some Ford limited-slip additive (also known as friction modifier). Three ounces of additive will treat one quart of oil. I don’t know what year yours it but on most 80s if the axle cod is just a # then it is open if there is an H before the # then it is a limited slip.
Code: Axle&Ratio:
13 Open 4.11
16 Open 3.50
19 Open 3.55
H3 Limited Slip 4.11
H6 Limited Slip 3.50
H9 Limited Slip 3.55
Code: Axle&Ratio:
13 Open 4.11
16 Open 3.50
19 Open 3.55
H3 Limited Slip 4.11
H6 Limited Slip 3.50
H9 Limited Slip 3.55
