AutoZone has regular gear oil.

 

Ok so how do I know if I have limited slip?

 

Check the axle code on the door jamb. You will see one of the numbers.

Regular diff I would just use 80w-90 gear oil. LS I would use 75w-90 synthetic. Some gear oil comes with modifier with it, but I add my own instead to be 100% certain.

12 - 2.73 non-limited slip (f150)
19 — 3.55 non-limited slip (Econoline, F-150)
18 — 3.08 non-limited slip (F-150)
17 — 3.31 non-limited slip (Econoline)
H7 - 3.31 limited slip (F150)
H8 - 3.08 limited slip (f150)
H9 — 3.55 limited slip (F-150, F-250)
B6 — 3.73 limited slip (F-150, F-250)
24 — 3.73 (Econoline)
32 — 4.10 (Econoline)
35 — 4.09 (Econoline)
34 — 3.73 (Econoline)
39 — 3.55 (Econoline)
52 — 4.10 (Econoline)
56 — 4.10 (Econoline)
81 — 4.63 (Econoline)
27 — 3.31 non-limited slip (F-250)
26 — 3.73 non-limited slip (F-250)

 

Thanks for that list so I have the H9 a 3.55 with limited slip

 

I will be changing out my gears from 3.08 to 3.73 and will do some off road, light 4wheeling so should I just use the 75-90w? The only thing I will tow is very rarely a 5K lb camper and a 3500lb boat.

thanks

 

It will be fine.

 

You know, our trucks are fairly old. My truck doesn't have the original rear, actually it has been changed twice. If you really want to know if it's limited slip raise both rear tires. Spin one tire forward, if the other spins forward it is limited slip. If it spins backwards it is not.

 

So just find a 75w-90 that doesn't specify limited slip

 

My 98 4x4 uses SEA 75W-90 GL-5 gear lubricant in the front and SAE 75W-140 GL-5 synthetic gear lubricant with 4 ozs of friction modifier (Ford part number C8AZ-19B546-A) in the rear axle. You should really check with Ford for your vehicle because using the correct lubricant is really important.

 

You lucky son of a gun! That's what I wish I had on my truck. I have a code 19.