Oil question for rear end

[Daves1940Buick56S]

Well, it turned out to be a bit of a struggle with the rear end of my car. I had gotten a 3.42 pumpkin to replace my 4.44. So I had my mechanic do this work since he had the rear out anyway for the clutch and trans work. The "new" rear's bearings were all shot and had to be replaced. Also the rivets were loose and had to be replaced by nuts/bolts (already mentioned this in another thread).

But the gears turned out to be pretty worn and my mech had to struggle to get the best adjustment, lots of slop. It still howls pretty good and I know that I will have to replace the gears. But meanwhile I am trying to get heavier oil, like straight 250 weight, in there to quiet it up some. I have Penrite Transoil 250 but it is only GL1. The only straight 250 weight EP oil that I have found is Amsoil, but it is GL5, which I know can be harsh on older metals. Also something about it attacking the seals on the bearings as well. So, any other oils out there that are maybe GL4 in 250 weight? Or should I just go with the Transoil GL1 since the gears are howling anyway? Any other ideas?

Cheers, Dave

[Guest buickkuhn]

Sounds bad ,but I have bought many old cars and trucks with sawdust added to the rear axle fluid. If your plan is to replace it in the future you don't want to harm the axles or more than just gears . I actually drove my 65 ford fairlane with a 8" rear axle for about 7,000 miles then decided wanted to change that rear axle fluid found it to be thick muck smelled like old engine oil . I stopped trying to suck it out and then put some on a cloth it was soft like dryer lint . My dad walked in "said saw dust treatment you better just add what you have taken out , and run it " . I put another 5,000 miles on that car with that rear axle - never did sound bad ( maybe like tire noise) . Good luck

[Mark Shaw]

I use Texaco Thuban or Shell Dentax SAE 250.

You may have to go to an industrial lube supplier to get it; & it only comes in 5 gal. pails.