[Malky]

Did the 8.2" differential come with different bolt sizes for the ring gears? I have heard that up to '68, bolts were 3/8" and after that they were 7/16". If so, why does Auburn only offer one posi to cover this whole range of years?
Malcolm

[Malky]

Did the 8.2" differential come with different bolt sizes for the ring gears? I have heard that up to '68, bolts were 3/8" and after that they were 7/16". If so, why does Auburn only offer one posi to cover this whole range of years?
Malcolm

[gto1967]

Yes,and the later ones were left-hand thread.

"Why that's impossible...and yet it happened!"

['ol Pinion head]

'64-69 Pontiac 8.2 gears & Richmonds used smaller diam rh thread bolt. '70-72 used slightly larger diam lh thread bolts.

To use early style or Richmond gears on '70-72 8.2 Safe-T-Track carrier, need to go to hobbyshop & get some thin wall brass tubing. This takes up the slop. Make little spacers with Dremel tool & then insert in carrier flange. Finish by blue loctiting the bolts & torqueing to spec.

To use '70-72 8.2 gear with early carrier, will have to machine holes out in carrier. Rel easy with drill press.

If still searching, I may have some '69 8.2 Pontiac 3.23 gears, got to ck this last parts car. BTW, saw someone's "look at Buick's for 8.2 gears" post...'68-70 Buick 8.2 pinion gears used larger big pinion bearing & pinion is larger in the bearing area. Thus the '68-70 Buick gearset will not fit in 8.2 Pontiac 10 bolts. Found this out tearing down '70 GS rearend for a build long time back.

[Malky]

Thanks for great info, OPH. I had read a ton of stuff on 8.2" diffs but had never seen anything on this before. I have e-mailed Auburn about what size bolt holes they have in their Pro series 8.2 posi's, which I intend on buying when I have got some gears. I have a line on a 3.36 set right now.
Malcolm