Guys...I've been "going through" the different components of my car (engine, trans, brakes, etc.) and I'm wondering if I should open up the rear end and drain out the fluid and replace it with new. My car is a '65 Cutlass with 57,000 miles (and as far as I know and can tell those are original miles). It has the conventional rear with 3.08's. What do you guys recommend...do it or let it be? I keep thinking that the fluid is 49 years old!!!

If I do it, what gear oil should I use?

Thanks.

 

If its an open rear just plain ol 80/90 wt gear oil. With a posi you will need the additive to go with it. It won't hurt to change the oil if it were original.

 

I would go ahead and change it. You will probably need a new cover gasket too.

 

Yes it should have been change about 20 years ago.

 

Thanks for the replies and advice guys...I'll go ahead and change it out.

 

One more question...how much gear fluid do I need? I believe it's around 3 pints. Can someone verify so I know how much to buy. Thanks again.

 

Buy two qts, it'll be enough.

 

Ok...thanks.