442ric

Rear differential and axles that is. I am attempting to sort out the various rear diffs used in the 442 over the years. What I have deduced so far:
1964 442--Pontiac/(Buick?)-sourced 8 1/8" ring, 10-bolt cover (notched at 3-o'clock and 9-0'clock)
1965 442--Pontiac/Buick-sourced 8 1/8" ring, 10-bolt cover (notched at 3-o'clock and 9-0'clock)
1966 442 and W30--Pontiac/Buick-sourced 8 1/8" ring, 10-bolt cover (notched at 3-o'clock and 9-0'clock); Olds-sourced 8 1/2" ring, 12-bolt cover (late)
1967 442 and W30--Pontiac/Buick-sourced 8 1/8" ring, 10-bolt cover (notched at 3-o'clock and 9-0'clock); Olds-sourced 8 1/2" ring, 12-bolt cover
1968 442--Olds-sourced 8 1/2" ring, 12-bolt cover; 442, W30, H/O-- H.D. Olds, 12-bolt cover (no notches); Chevy Canada (McKinnon)-sourced, 8 7/8" ring, 12-bolt cover, with Oshawa-built units only - no W Machines or H/Os
1969 442--Olds-sourced 8 1/2" ring, 12-bolt cover; 442, W30, H/O-- H.D. Olds, 12-bolt cover (no notches); Chevy Canada (McKinnon)-sourced, 8 7/8" ring, 12-bolt cover, with Oshawa-built units only - no W machines or H/Os
1970 442, W30--Olds-sourced 8 1/2" ring, 12-bolt cover; 442, W30 w/W27 12-bolt cast Al cover w/ Al center section
1971 442, W30--Olds-sourced 8 1/2" ring, 10-bolt stamped steel cover or 10-bolt cast Al cover (with W27 only)
1972 442, W30, H/O--Olds-sourced 8 1/2" ring, 10-bolt cover
1973 442, H/O--Olds-sourced 8 1/2"ring, 10-bolt cover; Buick-sourced 8 1/2" ring, 10-bolt cover; Chevy-sourced 8 1/2" ring, 10-bolt cover
1974 442, H/O--Olds-sourced 8 1/2" ring, 10-bolt cover; Buick-sourced 8 1/2" ring, 10-bolt cover; Chevy-sourced 8 1/2" ring, 10-bolt cover
1975 442, H/O--Olds-sourced 8 1/2" ring, 10-bolt cover; Buick-sourced 8 1/2" ring, 10-bolt cover; Chevy-sourced 8 1/2" ring, 10-bolt cover
1976 442--Olds-sourced 8 1/2" ring, 10-bolt cover; Buick-sourced 8 1/2" ring, 10-bolt cover; Chevy-sourced 8 1/2" ring, 10-bolt cover
1977 442--Olds-sourced 8 1/2" ring, 10-bolt cover; Buick-sourced 8 1/2" ring, 10-bolt cover; Chevy-sourced 8 1/2" ring, 10-bolt cover
1978 442-- Chevy-sourced 7 1/2" ring, 10-bolt cover
1979 442, H/O-- Chevy-sourced 7 1/2" ring, 10-bolt cover
1980 442-- Chevy-sourced 7 1/2" ring, 10-bolt cover
1983 H/O-- Chevy-sourced 7 1/2" ring, 10-bolt cover
1984 H/O-- Chevy-sourced 8 1/2" ring, 10-bolt cover
1985 442-- Chevy-sourced 8 1/2" ring, 10-bolt cover
1986 442-- Chevy-sourced 8 1/2" ring, 10-bolt cover
1987 442-- Chevy-sourced 8 1/2" ring, 10-bolt cover

If any of you can supply pics of the various rear ends and their covers, that would help greatly.
Please correct me if I am wrong in any of the above entries.

mmurphy77

I could be wrong but I always thought the BOP rears (10 or 12 bolt cover) had an 8.2" ring gear until '71 when they went to the "Corporate" 10-bolt that had the 8.5" ring gear. Also I think only the '83 H/O had the 7.5' gear then in '84 they went to the 8.5". I'm sorry if I'm WAY off with all this. It's just what I've been told.

joe_padavano

The Type O was used on the 1967 cars also. I have one that I personally pulled from an original 1967 Cutlass convertible.

442ric

Thanks, Mike. I made changes to the chart. Checked my '87 Buick manual and found the turbo V6 did use the 8.5 rear. I know that the Olds 442 and Buick GN both used the same rears in the late '80s. I also ukpdated the Pontiac rears to the 8.125" ring gear.

442ric

Thanks for that Joe. There was probably some cross-over late in the model year as Olds was transitioning to their own diff for '68.

Was that a 12-bolt cover?

joe_padavano

Yes, in fact it is exactly the same housing, by part number, as the one used in 1968, despite the 1.5" difference in track width normally between the 64-67 cars and the 68-72 cars.

442ric

What was the history of the donor car? Is it possible that the rear was swapped into that car before you came into its possession?

TK-65

Nope, father has a 67 and parted a 67 with a 12 bolt cover 10 bolt.

67442nut

Good thread.
After all these years I still have a time getting rear ends straight.
I had a '67 Cutlass 3-speed floor shift car that had a 12-bolt (cover)
10 bolt rear with a 3.08 gear.

Oldsmobility.com has a really good section on Olds rear ends:
http://www.oldsmobility.com/old/reardiffs.htm

http://www.oldsmobility.com/old/10bolt-tech.htm

joe_padavano

The factoryparts book documents the use of the Type O axle in the 1967 cars. It also shows that the 67 and 68 housings are the same part number and thus the same width.

oldsguybry

which rear end do I have ? lol... its a 72 CS 350 4barrel single exhaust originally

Run to Rund

The Olds Service Guild Bulletin (May 66 iirc) documented that some late 66s had the Type O. High numerical ratios weren't available until later, so the Type P continued in 66-7 for performance ratios like 3.91, 4.11, etc.

BIGJERR

Whoops..........Broke my Olds rearend many years ago and went 12 bolt Chevy and never looked back........The Olds rearend broke when I was running 14s.........Jerr

442ric

Thanks guys, I've updated the listing.

I've also added Buick-sourced axle ***'ys to the mix for at least '65-'67. Can anyone confirm the use of Buick rears for '64?

Still looking for pics for all O, C and K type rears.

mmurphy77

If it's the rear it was 'born' with then it should be the 'Corporate' 10-bolt which had the 8.5" ring gear. Strong rear for a 10-bolt.

67442nut

Does what your calling the "Corporate" 10-bolt have tapered axle bearings?

Aceshigh

+1

mmurphy77

Yes, it should be the type 'O' rear and should have the open tapered, pressed on bearing with no 'C' clips to retain the axles.

joe_padavano

Just to be clear, "Type O" refers to the axles used on late 1966 through 1970 cars that have the 12 bolt cover but 10 bolt ring gear. A 1972 Cutlass has a" corporate" 10 bolt axle, but it does have the Olds-unique bolt-in axles. Differential and gears do interchange with other 10 bolt axles.

mmurphy77

Thanks Joe. I meant the type 'O' style axle in the 'Corporate' rear and was not clear in conveying that. Thanks for clarification.