2007 at the Hammond Barn

[Alex Blair (RIP)]

Originally posted by Paul Singleton
I can't see any problems using 80W-90 gear oil. The specs Alex Blair refers to are before multigrade oils were available.

Paul

Paul
Correct me if I'm wrong but multi grade oils contain detergents...
Not a great thing for gear boxes..of any kind in a CMP Vehicle..as they tend to attack certain metals and seals..
Just to finish off that thought the multi-grade oils use something called a VI improver or modifier. These additaves will be used up (break down) and so the oil eventually reverts back to the base oil viscosities. The ISO mono-grades will also sheer down but at a significently lower percentage. So the mono grades will probably have a longer usable life in the drive - as long as they do not get contaminated.
So Bob,to answer your question ,if it were mine I'd be sticking to the old stuff..The multi grades are fine in the new ,higher speed gear boxes where they are changed regularly...The highest speed these old honeys are going to see is when they make the beer run a couple of times a year..maybe..