Hey guys, been looking through my classic industry's book and looking in the FAQ 10 bolt thread so I gathered that splines matter of course. For posi units it doesn't say anything about a selection between carriers, just gears. So if I have one for a 3.42 series 3 could that fit in a series 2 carrier with the same gear designed for it?

I have a 3.42, posi, series 3, with 26 splines and I'm thinking about putting the posi in a rear end with a 3.73+ designed for a series 2 and 26spline but currently has 3.08.

 

As far as I can tell you are asking if the parts from one housing will fit in another housing. There is no difference in the housing. You can put any gear and any axle spline in any housing, as long as all of the parts work together.


You can't use 3 series gears on a 2 series differential (without a spacer, which is a very bad idea). You can't use 2 series gears on a 3 series differential.

 

No, not the gears. Just the posi? My Camaro book says

"26 spline 3.08 down.... $400 P/N xxxx"

26Spline 3.23 up... $400 P/N xxxx"

I doesnt say anything about carrier just the gear. So if I had a posi on a 3.42 series 3, could that posi be mated to a proper 3.42 series 2?

 

No.

 

Carriers are different according to the gears they go with. Specifically, the flange the ring gear mounts to, is moved about .400" farther away from the pinion centerline, on the carrier for the low numbered ratios.



Pretty obvious in this pic... 2 series on the left, 3 series on the right. Note how on the 3 series one, the flange is sorta cone-shaped, moving it closer to the pinion, but on the 2 series one, the flange is flat, moving it farther away.

 

Ok I understand now! Odd Classic Industry doesnt even mention carriers. Thanks again Sofaking and BGH.