posi fluid

[73 challenger 440]

i need to change my fluid in the  rear end, what weight do I need and is there posi additive I need as well..
thanks

[RaptorF229]

I use amsoil SVG and the Slip Lock additive. ITs all synthetic stuff.



gearoil
http://www.amsoil.com/storefront/svg.aspx

sliplock
http://www.amsoil.com/storefront/ada.aspx

[Chryco Psycho]

2 choices , 80-90w gear oil or synthetic 75-90w not brand specific
 most oil require friction modifier added unless it specifies otherwise 

[ksierens]

I used to buy mine from the GM dealer, I will see if I still have some, but I think I heard somewhere that it was no longer available.

I think that Jay Leno had mentioned something about some trans/rear additive that he was using that he liked in the Challenger video on his web site.

[73 challenger 440]

my Dad has some gm posi additive, but not sure if I can use that, I am not sure if the corvette rearends are different.. I went to pepboys but that didn't have any amsoil

[Chryco Psycho]

GM & Mopar additive is the same stuff

[kudakidd]

You may be new but please remember;posi is a GM term, Sure Grip is Mopar.

[trouble]

This is what I used Last year for my 410 dana.
It was recommended by someone here.

[Moparal]

You may be new but please remember;posi is a GM term, Sure Grip is Mopar.

You hang out on moparts a bunch?   They push that sure grip **** over there.   If you had a 742 unit , odds are you had a powerlock not a cone sure grip.  Or a dana 60 with a powerlock. In the 70's when we were looking for a new chunk with bigger gears everyone no matter what you drove was looking for a posi (positive traction unit)   I think some people get offended and shy away from certain posts when people get so picky.  I'm not trying to come down on anyone, just asking some to lighten up a bit.