[My1967Chevelle]

I have been looking for a 67 chevelle 12 bolt I have had no luck yet. I really want the 65 to 67 12 bolt not a 68 to 72. I don 't care if it has bolt on coil springs. I just want the 65 to 67 length.

So my real question is I found a 66 or 67 GTO in the junkyard with a 12 bolt, but I am not sure if they are the same as the Chevelle 12 bolt. I know an olds rear is a 8.5 carrier with 12 bolt cover. When I look on ebay everyone advertises the 12 bolts as Chevelle, GTO, 442 and other A body cars. If anyone has an information please let me know. Thank you

 

[DG]

Externally...yes, it will bolt up.

Internally...no, no Chevy parts *Gears, carrier, pinion....will interchange.

 

[mr 4 speed]

No such thing as a Pontiac 12 bolt.
There is Chevy 12 bolts and Oldsmobile 12 bolts.
Pontiac starting using the 12 bolt Chevy rearends in 1970 in 455 HO powered GTO's and Grand Prix

FYI:
http://cgi.ebay.com/ebaymotors/1970...ryZ34208QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The part number listed on the ring gear in the auction is 3862689 which is for a Chevy 12 bolt


http://cgi.ebay.com/ebaymotors/Pont...oryZ6422QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[covertolds]

Look at the cover. A Chevy 12 bolt has an upsidedown V on it. This helps to lubricate the differential bearings. The cover also has some kinda flat spots on the outer edges of it.

An Olds 12 bolt has a smooth cover that is almost perfectly round.

As mentioned before, they will both bolt into an A body, but the internals are different.

 

[shadowgray396]

The Oldsmobile rearend looks different in the front. Attached is a picture of what it looks like. It also has smaller bearings and is not as good as a chevy. I recently pulled my rear end out from under my 70 chevelle and found out it had an oldsmobile rearend. I talk with my gear guy and he said parts are expensive for it and hard to get. Its really a 10 bolt with a 12 cover

 

[My1967Chevelle]

Thank you for the information. Next time I go to the junkyard I will have to get under the car and look at it better and see if I can find any casting numbers and look at the cover better. I only looked at it from the back and counted the bolts and there was 12 bolts on the cover, but I dont remember if it had the upside down v. Maybe someone installed a 12 bolt chevy on the GTO. All the 66 and 67 chevelles the guy has all have 10 bolts on them. Thanks again everyone

 

[big gear head]

Some of the old GTOs had the Chevy 12 bolt.

 

[71elkySS454]

As was previous posted, NO GTO's prior to 70 ever came from the factory with a 12 bolt. They were all 10 bolts, so the GTO in the salvage yard does not have the original rear end. The correct info has also been posted about the difference in a 12 bolt Chevy and 12 bolt Olds.

 

[BLOWNBBC]

That olds rearend is actually a 10-bolt. It has a 12 bolt cover but a 10 bolt ring gear. It also has tiny axles which are, lucky for them, retained by press on bearings like a ford 9 inch. It could be a good rear for a low HP application.

 

[kab1]

That olds rearend is actually a 10-bolt. It has a 12 bolt cover but a 10 bolt ring gear. It also has tiny axles which are, lucky for them, retained by press on bearings like a ford 9 inch. It could be a good rear for a low HP application.

That olds rearend is actually a 10-bolt. It has a 12 bolt cover but a 10 bolt ring gear. It also has tiny axles which are, lucky for them, retained by press on bearings like a ford 9 inch. It could be a good rear for a low HP application.

That olds rearend is actually a 10-bolt. It has a 12 bolt cover but a 10 bolt ring gear. It also has tiny axles which are, lucky for them, retained by press on bearings like a ford 9 inch. It could be a good rear for a low HP application.

That olds rearend is actually a 10-bolt. It has a 12 bolt cover but a 10 bolt ring gear. It also has tiny axles which are, lucky for them, retained by press on bearings like a ford 9 inch. It could be a good rear for a low HP application.

Press on bearings suck. I had one come apart when making a turn and the axle walked out. It was miserable trying to get the outer race out of the housing along side the road.

 

[oldcutlass]

Press on bearings suck. I had one come apart when making a turn and the axle walked out. It was miserable trying to get the outer race out of the housing along side the road.

While you resurrected a 15 year old thread, your story is a bit off. There is a bearing retainer (lock collar) pressed on the axle that prevents it from coming out of the housing in addition to the bolt on plate. It's not a repair that easily could be done on the side of the road no matter what rear end you're running.

 

[GM man]

No such thing as a Pontiac 12 bolt.
There is Chevy 12 bolts and Oldsmobile 12 bolts.
Pontiac starting using the 12 bolt Chevy rearends in 1970 in 455 HO powered GTO's and Grand Prix

FYI:
http://cgi.ebay.com/ebaymotors/1970...ryZ34208QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The part number listed on the ring gear in the auction is 3862689 which is for a Chevy 12 bolt


http://cgi.ebay.com/ebaymotors/Pont...oryZ6422QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Never knew that . Now I gotta look at the 66 Pontiac rear end I've got

 

[GM man]

Some of the old GTOs had the Chevy 12 bolt.

From the factory?

 

[oldcutlass]

From the factory?

No GTO's had 12 bolts, but Candian Oldsmobiles did.