8.2 BOP gear question

Discussion in 'Got gears?' started by Todd69GS, Jun 14, 2006.

  1. Todd69GS

    Todd69GS Silver Level contributor

    I know that the 8.2 posi units offered by Eaton and Auburn will not work on our Buick 8.2 rears but will the ring and pinion gears that richmond offers for the 8.2 bop work on our factory 8.2 posi units?
    I'd like to step up to a larger gear (2.93 now) but I'm having trouble finding used gears. If I bought a set of Richmond 3.55 BOP gears would I be able to use a spacer to make these work on my 2 series posi?
     
  2. Topless64-455

    Topless64-455 Well-Known Member

    First on all, I thought the new carriers would work in the Buick housings. I had a 2.93 posi that I had a guy put 3.36 gears on with a spacer. The big problem was the bolts on the ring gear were smaller than the ones on the 2.93 gear. We had to make shims/or filler tubes to take up the looseness from the small ring bolts. He could not get the perfert pattern but acceptable for my use.
     
  3. oPh

    oPh Well-Known Member

    The '68-70 BUICK 8.2 10 bolt ring & pinion, & carriers are odd ducks. The $250 Richmond 8.2 "BOP" gears will not bolt in the '68-70 BUICK 8.2 rears. Have detailed a lot, but not all of this before.

    While the '68-70 BUICK 8.2 has a pinion length that is nearly the same, the common 8.2 BOP pinion takes a smaller bore M89449 pinion bearing, while the '68-70 BUICK 8.2 10 bolt pinion takes the M804049 bearing. The master head dimension on the two different styles of 8.2 gear sets is most probably different. Need to measure to be 100% sure.

    Carrier wise, the '68-70 BUICK 8.2 10 bolt carrier was avail in 4 different ratio's or "splits", while the PONTIAC (BOP) carriers were only avail in three. Several months ago, I asked for dimensions of any loose ' 68-70 BUICK 8.2 carriers, to compare to the "BOP" (Pontiac) versions I have on the shelf, basically trying to & find out what the limits were with & w/o a Mr Gasket ring gear spacer, when adapting the mid ratio (2.93-3.08, 3.23) Pontiac 8.2 carrier into 68-70 BUICK 8.2 rearends. Having performed such a low ratio carrier swap in the past, it is doable by having a bushing machined to slip onto the Pontiac 8.2 carriers lh bearing boss to accept the larger diam carrier bearing used in the '68-70 BUICK 8.2 housing.

    Getting around the different diam ring gear bolt issue... have made thin wall brass bushings in the past to mount 3.36, 3.55, & aftermarket (Richmond) '64-69 Pontiac 8.2 gears on a '70-72 Pontiac 8.2 posi carrier. Believe this is what Topless64-455 had to have done as well. Similiar bushings would also be needed, if one was trying to adapt a '64-69 Pontiac 8.2 ring gear, or new Richmond "BOP" 8.2 ring gear onto a '68-70 BUICK 8.2 posi carrier. Red loctite is also a must. Having used the brass bushings before, I don't mind using them on street cruiser type vehicles, but really would rather not be forced to use them with a ring gear spacer.

    Add up everything that is a nightmare with dealing with the '68-70 Buick 8.2's, & it's a whole lot easier, & cheaper to go with a complete pro built '71-72 8.5 A-body posi rear. 1st, the 8.5 A-body rear uses tapered axle bearing axles that don't seize like the earlier sealed axle bearing A-body rears. The 8.5 A-body also is stronger & benefits from wide variety of aftermarket parts which can transform it from a well designed strong r/e into a VERY strong aftermarket posi r/e capable of low 1.40 60 foot passes in a 3800 A-body.

    Got to run, will ck back in late tonight.
    :3gears:
    Roger
     

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