Oil foam in diff normal

[Frankb]

69 GTX with original Dana. Cover was leaking. When I pulled off there was foam in the diff. Is this normal?

 

[Fran Blacker]

Vent clogged or let water in or moisture/water got in. Maybe wrong lube foaming.

 

[pnora]

Some foam can be expected. I would make sure the vent is good and clean. Refill with new quality gear lube to the proper level. Some gear oils and additives can foam to a degree. I will bet you had driven the car and the oil was good and hot when you pulled the cover.

 

[Fran Blacker]

Do you have picture of lube that came out? If is a little milky it's probably moisture.

 

[AR67GTX]

I’ve never seen that when I pulled my 8-3/4 out but who knows? Maybe something peculiar to the lube in it. Or moisture as Fran suggested.

 

[Black_Sheep]

 

[Frankb]

After 24 hours of cover off that stuff is still in the gear. Oil looks like its contaminated with something. Cant be water. Car has never seen rain or wet road since restoration. Never made noise. Strange.

 

[old guys rule]

Good stuff, thanks

 

[Fran Blacker]

Clean what you can, check vent to see it's not clogged. Get the correct lube and a couple bottles of ford limited slip lube. Add one bottle of the ford and fill rear to proper level. Drive it some 50/100 miles. Drain into a clean tub and see what it looks like. If it looks good you might want put it back in. That soup in the pan somebody more knowledge than I could tell you if it's friction material.

 

[Geoff 2]

Foam is a poor lubricant.
I would refill with pre-mixed LSD diff oil, which has the correct additives already added. I use Redline 80/140.

 

[Frankb]

Thanks fellas. Will clean everything up and refill. I use Lucas 80-90 with some Ford friction modifier.

 

[451Mopar]

I recommend the RedLine synthetic gear oils.
Red Line Synthetic Oil. Gear Oil

I have no association with them, just been using their products for over 30 years after switching from Amsoil.
Amsoil is good too, but back in the 1980's you had to get it through their multi-level distributors
List of multi-level marketing companies - Wikipedia

 

[Geoff 2]

I do not understand why people use oil.....then add additives. They must think they know more than the oil companies that have huge laboratories where the correct additives are added in the correct proportion.......for the application.

 

[Fran Blacker]

Father bought a 64 Olds Starfire with posi. We were going around a sharp corner shortly after delivery rear clunked like he ran over a curb. Took it to the dealer several times, they put additive in helped but didn't get rid of it. Whale oil.