Will a 10 or 12 bolt posi unit an gears for a car work on a truck? I would assume gears r gears but wanna make sure. Thanks

 

10 to 10. 12 to 12 as far as i know. but not 10- 12 or 12 - 10. Unless the splines are different from car to truck but I'm not sure on that.

 

Well i was wondering if i could buy a posi unit an gears for a car, match them up to my bolt an spline and put them on my truck.

 

what year is your truck?? the 93 in your sig?? if so and its a half ton... you have an 8.5 inch 10 bolt 28 spline rear end....

if its a 88-98 then you can use a old style 8.5" posi unit out of some cars that got it.. but you must make sure that it is a 28 spline, 3 series carrier.. unless you want to run some tall gears...

if your referring to the 10 bolt on a 93-2002 F-body.. then NO it is a 7.5" rear end...

 

Yes half ton 93 in sig. Ok so i have match up all three things then. I havnt ever dealt with rear ends.

 

the truck 8.5 is a 30 spline unit. i have one i put 3.90 gears and auburn posi in. and only the one carrier in 10bolt. 12bolt had different series. best just to go thru summit, jegs or one of the dealers on here. not that expensive to buy new. works out the same if you have to rebuild the old posi you get

 

So i just needa find 8.5 30 stuff for my rear end then get the gear i want correct?

 

From Randy’s Ring & Pinion
GM 8.5 – Years Used on ½ Ton GM Pickup: (1979 – 2001)
10 bolt cover with 8.5” ring gear. Ring gear has 10 bolts and pinion has 30 spline. C/clip rear could have 28 or 30 spline axles. All 92 & up trucks and SUVs will have 30 spline axles.

GM 8.6 – Years Used on ½ Ton GM Pickup: (1999 – 2009)
10 bolt cover with 8.5” ring gear. Has 30 spline C/clip axles. Differential is found in 99 on up trucks, and will always have disc brakes.

Obviously, their web-site needs updated for the description a little for the 8.6, as we all know that GM switched back to drum brakes, but that’s besides the point and you can still gather what information you need from the listings.

 

Yes your right youngbuck you have a Z71 so you will have 30 spline, the 2wds from 88-98 had 28 spline units.... (10 bolt)

but it is not the same as the new trucks, the bearings changed.

and there are different series carriers for an 8.5 rear end... 28 spline....

just make sure you get the right bearings

 

Is it true that the 99's could have either the old style or new style bearings?