put a 9 bolt in my IROC a month or so back. I was planning on putting my 10 bolt back in so I'd bought gear lube and pos additive. When I changed lanes and prepped the 9 bolt I just put the pos additive and gear lube in it and installed it. Not having any experience with 9 bolts I just got to wondering if I should have used the pos additive. Any input is welcome.

 

you'd want the posi additive in any clutch type posi unit, any other type of posi wouldn't need it

 

Thanks. After looking inside the housing I wasn't really sure it had clutches/springs. It doesn't look anything like the 10 bolt pos units. I needed a disc brake rear end and it was sitting out in the building so I put it in the car. Thanks again.

 

You will NOT want to use the fluid. The 9 Bolts are Cone type and require friction to hold unlike the 10 bolt units.