I picked up a TM code 3.42 posi with a 588 carrier a few weeks ago. I'm planning on doing the swap out over this coming weekend. I've read and heard 100 different recommendations from 100 different sources about what weight gear oil and what additive to fill this with. Anyone with this original gear and carrier combo mind telling me what you're using please?

 

I am interested, as well. I picked up a NOS 588 carrier about three years ago, and subsequently found an old NOS set of Richmond Gears 3.42:1. I hope to install them later this summer as part of my '68 4-4-2 mechanical refresh.

 

90 weight and a posi additive.

 

What Oldcutlass said. I called Monzaz directly and had a chat this afternoon on the phone, he was a big help. He said NON synthetic 90 weight and additive.

 

Remember this is Hypoid gear fluid not just a 90w oil...
Jim