Relevant topic for me. On my list to check/fill both the transmission and rear diff on my 1951.
I'm perfectly clear on the transmission - straight mineral 90w.
But I'm a little confused on the rear end now that I read that shop manual excerpt. What belongs in there?
Also, of one doesn't know WHAT is in the trans or diff from previous owner....is it best to drain and refill with proper stuff?
I can tell from the very slow drip in my rear diff....that it's reddish colored. Almost looks like ATF.
