Paaro

Has there been any positraction rears for full size Oldsmobiles? If not, what others would fit? Have a 1970 98, for which there is none.

joe_padavano

Your car came from the factory with a 9.3" Type O axle. This was not used in any other vehicle, only the 1966-1970 full size Oldsmobiles. No one makes aftermarket parts for it. Nothing interchanges. Your only option is to find a used factory anti-spin center section, or change the entire rear axle.

Paaro

Thank you for your swift answer! I was slowly coming tgo the same understanding, but it feels great to get some information. Now I'm going to look into the search for 'a used factory anti-spin center section' or an entire rear axle..
On page 4B-20 in Chassis service manual they say 'Anti-spin conersion information', which reads: The case assembly (less ring gear and side bearings) is available for converting a conventional differential to Anti-Spin. The ring gear and side bearings, if in good condition, can be used with the Anti-Spin case assembly.
One way or another I would like my old (named 'Goldie') to get Anti-Spin.
Best regards,
Paaro

Kennybill

Both of my 1967 98's have 3:08 anti-spin rearends. Both rearends car out of field cars from Pennsylvania. Because of the hills and winter weather a lot of buyers ordered the anti-spin back in the day. It was the "hot" setup with snow tires and or tire chains.

joe_padavano

Here is a service bulletin that covers procedures for the Type O axle. Note that this covers both the 8.5" version used in the A-body cars and the 9.3" version used in the full size cars.

Paaro

Thanks! I'll keep an eye on Pensylvania. Might find something there.
Paaro

Paaro

Thanks! Looks ery interesting, as I'm in the 'search' mode.
Paaro

SmirchIs#1

I have a dozen or so fullsize car Eaton posi units from 60's and early seventies.Unfortunatly I never labeled them,because I have always concentrated on muscle cars.If someone can supply posi case #'s I probably have what you need.

joe_padavano

That's good to know. I don't suppose you have any 3.23 or even 3.42 gear sets for the Type O 9.3, do you? (Hey, I have to try)

Be aware that the Olds full size cars from that period used both the Type O 9.3" and the Pontiac 8.875" axles, and the carriers obviously do not interchange. The Pontiac axles actually have decent aftermarket support.

Paaro

SmirchIs#1; Thank you! I'll keep it in mind!

SmirchIs#1

I did look at the gear sets and as you expected,nothing but prairie gears.Wish I could ID the posi units.