Originally Posted By 440PURSUIT
Interesting thread.

Im just finishing a rebuilt 4 speed in my 65 Coronet.
I added a GL5 90 weight.
I have about 5 miles on Car.

Can I just drain and refill with 75/80 GL4?

Or is a cleaner needed?

Thanks


Sure can , there will be a small residual amount left inside and that shouldn't really matter. Let it drain overnight .