Hi folks, Can anybody help with this?
My 67 Chevelle has a 12 bolt rear that I was told came from a 68 442 and recently broke the ring gear at Super Chevy Bristol and plan to change it out for one of the new Strange S60 rears. Anyway how do I determine if this is a 442 rear and what it might be worth if I try to sale it?

Case has BP and 394139.

Thanks for any help offered.
Jim

 

Well, if it has a smooth 12 bolt cover (instead of the inverted "V" notch on the Chevy axles), it's a Type O axle. The Type O was only used under the Cutlass line from mid-1966 through the end of the 1970 model year. These are NOT "12 bolt" axles, despite what some sellers claim. The ring gear in the Type O is only 8.5" in diameter and is held to the carrier with ten bolts. All parts are unique to the Type O and are difficult (but not impossible) to get.

Assuming this is an Anti-Spin axle (Olds-speak for posi), and assuming the broken ring gear is the only problem (and didn't cause collateral damage to the carrier), value will be in the two-three hundred dollar range. What series carrier is it?

 

Hi Joe, Thanks for your response. Rear does have a smooth cover and ring gear also measures 8.5" as you stated and most likely why my 496 ate it's lunch. It does have 31 spline axles and had 3:90 gears. No other damage is visible to posi unit or inside of case.

Again Thanks!
Jim

 

First you have to know if it is a Olds O type rearend, which will have bolt in axles, smooth round 12 bolt cover, and a 10 bolt ring gears. It can also be a Canadian built, which will have a Chevy C clip type axles. The Olds is hard to find parts, and is worth money. It will have a two cap letter ,a like SD, stamped on the right axle tube Also 68 is rare, as it will have 31 spline axles. Tell me what the letter are if it is a type O, and I can tell you the gear ratio.

 

Hi Harv, Yep it does have 31 spline bolt in axles as well as all the other info you mentioned I didn't see any stampings on the tubes put it has a heavy coat of paint on it. I plan to try to clean off some of the paint after I get the whole thing out of the car. Only stampings I could find were the numbers on front of center section as I mentioned in my first post. The gears were 3:90 but not sure if they are GM gears.

Cant get you much more info than that for now, car is locked up in a friends shop and he is doing the Cruising the coast thing this week.

Thanks for your help!
Jim