67Skylark

Time to change gears, and bearings. I don't know what differential I have. I know it's not original to the car (67 Buick Skylark). I'm under the impression it is an 8.5 from an early 70's A-Body just not sure. I've been on most of the Buick and Oldsmobile forums trying to track numbers, no luck. The numbers stamped on the right axel tube SA B323 2, it does not use C-clips, and looks to be all factory.

FirstYrLS1Z

iTrader: (4)

Googleling that 1234668 number on the ring gear points to the GM 8.5" 10 bolt. Measuring the largest diameter of the ring gear should be about 8.5",that's where the 8.5 value comes from. An 8.2 rear ring gear measures about 8.2".
Ring gear bolts-7.5,7.625,8.5,8.625 rears have 7/16-20 LEFT HAND thread,8.2 rears have 3/8-24 RIGHT HAND thread.
The ring gear bolts in the pic appear to be of 7/16 thread size.

67Skylark

I've done the ring gear part number gooogle/bing searches, for each one that says it's one, you can find another that says its the other. I heard about the bolts but hate to open it up until I have the parts on hand to complete repairs. These pictures where taken a couple of years ago. I've also heard if pinion nut takes 1 1/4 socket it is a 8.5, I have pulled the driveshaft and confirmed 1 1/4 fits, also has bolt and straps instead of U-bolts, also a clue towards the 8.5... Anybody know for sure? Can anyone decode the "SA B 323 2" from the front of the rh axel tube?

SS69LS1

iTrader: (108)

Those 2 square ears on the lower corners of the pumpkin point to an 8.5. The 8.2 doesnt have those. Scott

SS69LS1

iTrader: (108)

this should help

http://www.smokemup.com/bb/viewtopic...56193cba6ef590

Just scroll down a few and there is a good pic of the 2 side by side

Jays_SSZ28

iTrader: (2)

The ring gear bolts are all you need to know. 7/16 left hand thread is an 8.5.
The gasket says it's a BOP 8.5

67Skylark

Can you tell by the photo the bolts are the 7/16 left hand? The current rear cover has the "c" cutouts on each side, I would think either style cover would seal, I'm guessing the bolt pattern is the same, but not sure. Anyone know? You typed BOP 8.5, is there such an item? I've only read about pre 71 BOP 8.2's and 71 and up 8.5 corporate. My knowledge of rear differentials is very very limited. Thanks for the help

Jays_SSZ28

iTrader: (2)

The 7/16 bolts have an 3/4 hex. If it was an 8.2 it would have 3/8 ring gear bolts with 9/16 hex heads.

I recall long ago before the internet, seeing identification information stating the BOP 10 bolt having the cut-outs on the sides.

The easiest way to ID it that I know of is to put a wrench on a ring gear bolt. Theres no such thing as an 8.5 with 3/8" ring gear bolts.

RPM WS6

iTrader: (3)

My 1973-built 8.5" has those. I can't say that I've ever seen an 8.2 with them. The comparison picture in the link above also is consistent with this and with what I've seen.

67Skylark

It's at the shop (Dependable Drive Shaft Clearwater FL), all torn down. It is an 8.5 with bolt in axles(no C-clips required). Best guess at this point is that it came from a 1971 Buick. Only odd thing was the axel bearing retaining clips were tack welded into place. Axel measurements were good, don't know why but weld cleaned up perfect and bearing pressed on nice and new clips fit well, no welding required. New 373 Richmond gear set, Timken bearings through out, New Spicer axel bearings, should be back on the road Monday, Thanks to Roger and crew at the shop.

speedtigger

iTrader: (16)

Roger is a good guy. We did a lot of business over the years.

RedFirehawk

iTrader: (5)

They would tac weld that sleeve to keep it from coming off and the axle sliding out of the the rearend . I had it happen. Its worth being tac welded for security.

67Skylark

The axels did have .100 end play so Roger built a shim to remove the play. Feels Great. He didn't feel any reason to weld clip unless it was a dirt track or figure 8 racer. Having problems with the LY6 cam phaser, so I haven't been able to drive it yet. It will code 2135 and gas pedal drops out and it goes into limp mode.

RedFirehawk

iTrader: (5)

I had it happen on my street car that I drag raced. A lot of drag racers did it back in the day. Good luck.

G-BODY-JAMES

iTrader: (1)