489 case with posi??

[mikes68charger]

OK I bought a 489 case with posi with 3.91 gears 4 years ago. I was looking throw one of the other post and some one made the comment.

I want to lean toward the rear end too.....You don't specify,  but since this is a 4-speed car, I'm going under the assumption that this is a Sure-Grip rear end.   Did you put the proper additive in it  and not just the gear lube itself???

How do you know what type of posi I have? would it hurt If I just put the additive in the rear anyway?

[firefighter3931]

How do you know what type of posi I have? would it hurt If I just put the additive in the rear anyway?

Mike, there are 2 types of sure grip units....if your centersection is all original it will have the cone style unit installed. The easiest way to distinguish the two is to look at the unit itself. The cone style units will have a window whereby you can see the insides of the unit. Inside you will see a bunch of springs. There are no springs in the clutch style sure grips.


The Suregrip additive is available from the dealer. It is worthwhile adding the friction modifier to any SG equipped 3rd member.



Ron

[Dodge Don]

The additive goes in along with the gear lube. Stinks like skunk piss.