Hi I have a 10 bolt in my buick but cant seem to find out much about it. Was told it was a 71 cutlass rear end with posi. On the driver side of center section is the letters BD. On bottom it has cfo and 407296. The ujoint is held in with 4 bolts and 2 straps. From what I can tell on the axle tube casting looks like SS 02 7. If anyone could help out it'd be grateful.

 

You are looking for the number in the wrong place it is on the axle tube on passenger side! Look for letters example {to } which is not correct. Look for whatever is there. Then you can go to 442.com and find out what you have.I hope this helps.

 

Message sent.

 

You can find the tooth count stamped into the OD of the ring gear, like

13 41 and a few other characters

41/13 = the ratio for this example- 3.15- a poor example because that ratio has never been made as far as I know. Anyhow, at least one of the numbers is usually prime, to even out the wear across all the gear teeth.

Of course you can google the center section casting 6-digit number and see what is known about it.

What are your concerns?

 

Inquiring if 69skylark found the axle ratio code and if he might be thinking of selling the Oldsmobile rear axle and/or is looking for a Buick rear axle.

 

Olds 71 72 8.5 rear end.
Itt is a posi Trac Lock clutch type unit.
No parts for the unit anymore... They do last a long time so see how it goes...
Ratio will be on the outside diameter of the ring ...spin and wipe the outer edge you will find the ring part number gear tooth count of the ring and the pinion and maybe even a date code. see if you can get a picture will figure it out for you. Jim

J D

 

From the picture it looks as if you brok ethe spider gear? Yes No?

Ouch.

Might be able to help with that. Do you have the ability to tear down the rear and or posi unit? If not send us the posi we can go through it and replace that spider . We have some posi parts here to help.

 

SS code should be 3.23 posi.