8 3/4 posi question

[lordofrc]

i have a 67 charger and i have a 8 3/4 with 2.92 gears none posi and i bought a complete center section that is a sure grip 3.91 and i want to know exactly what i need to do to swap these. Also what is the correct fluid that needs to go in for the sure grip to work?

 

[Schober Motorsports]

Well, seeing that if you have a complete pumpkin ready to go, just switch em out. Since this new pumpkin has the true-lock/posi in it, you'll need to add a Limited Slip Additive. Thats really it. Couldn't be any easier, thank god for those 8 3/4's!

 

[eagleone1983]

If you're looking to keep numbers correct by keeping the center section for your car and swapping internals the sure grip will swap over. However, gears are specific to pumpkins (ex. gears for 489 will not work for a 741)

 

[Deleted member 214]

First, Mopar didn't make or use any "posi"s. That is a GM term. To swap out - take off the tires and drums. Unbolt the four bolts that old the axle to the housing - you can access them through a hole in the axle flange. Pull out the axles a foot or so. Unbolt the center section from the housing. Clean out all the old axle lube and clean the gasket surfaces. Install the new center section, slide the axles back in, add lube. Are the U-joints the same on both gear sections? If not, you may have to modify your driveshaft.

 

[Cranky]

5 bolts hold the axle retainer plate in place. Also, check the splines in the SureGrip to make sure they are aligned. Many people that put these together don't even think about that and if they are not aligned, you will have a very hard time getting your axles all the way in. I made a set of tools to check the tightness of used units plus I use them when I rebuild them. I stick one in a vise and place the carrier half on it when I start loading the parts into it and then use the other to make sure they are aligned before I tighten it up.

 

[lordofrc]

Thank you for the advice, can i get fluid for the sure grip anywhere or is there a special supplier?

 

[Cranky]

Gear oil plus the SG additive. I just use the same amount of STP for the additive and it seems to work just as well if not better...

 

[67 B-body]

5 bolts hold the axle retainer plate in place. Also, check the splines in the SureGrip to make sure they are aligned. Many people that put these together don't even think about that and if they are not aligned, you will have a very hard time getting your axles all the way in. I made a set of tools to check the tightness of used units plus I use them when I rebuild them. I stick one in a vise and place the carrier half on it when I start loading the parts into it and then use the other to make sure they are aligned before I tighten it up.

I think he needs to be sure he has the little spacer in there too for axles adjustments doesnt he?

 

[Cranky]

I think he needs to be sure he has the little spacer in there too for axles adjustments doesnt he?

The thrust pin. Yup. In the unit I show (cone type), the only way for it to come out is to take the unit apart. It looks like this and is trapped.....

The one that's in the clutch type unit is a two piece design and is pretty small and can come out with improper bearing adjustment (too tight) on the axles. I don't have a pic of it tho.