Payner44

I just got this '70 Cutlass Supreme convertible and put new front shoes on it. However, in doing so I discovered that the drums have the hub and bolts integrated in them. When looking to buy correct replacement drums I cannot find this configuration, but have seen it on Pontiacs and Buicks. Are they interchangeable with Oldsmobiles of the same years??

tru-blue 442

Pretty sure they are all the same from 64-72 on the a bodies. More penetrating oil and a bfh should help. The drums will rust onto the hub somewhat after so many years. Spin and soak, spin and soak at the lug bolts. The drum will come loose eventually.

Payner44

I think you misinterpreted my post. The drums came off very easily. What surprised me was the hub is actually part of the drum (not rust to it) and the bolts are pressed into the drum. No drum that I found online for this model/year was like that. It's just the drum that would go over the hub/bolts that is listed. This made me wonder if these drums are from another GM make of the same year, because Pontiac and Buicks are found to be configured this way.

tru-blue 442

Unfortunately the 70 CSM is a little vague on this point. But, if they are 70 Oldsmobile Cutlass/442, the drum and the hub should separate as I see it from this pic of the front drum. All of the ones I have ever worked on did. Of course, my eyes, memory and comprehension aren't what they used to be, ha.

svnt442

You have to knock the wheel studs out to separate the drum from the hub. I had to do this on a 70 post I had years ago due to the inner race being gouged into the hub and I needed to replace it.
Once you get the studs out it's not that difficult to replace the drum.

svnt442

Oh, and depending on how you do it you might have to replace the studs if you damage them.

Payner44

Again, in my case the hub is part of the drum...they are one piece of metal. You cannot separate them. The bolts/studs are pressed into the drum and can be knocked out if needed.

svnt442

No it's not. The drum is attached to the hub via the studs.

Payner44

Look, I posted here for clarification, not to get into a stupid, "I'm right, your wrong" string of posts. I know what I have, but am not going to spend the time posting pictures to prove it.

Sorry I f****ing asked!!

svnt442

This is straight out of the 1970 service manual. You can clearly see the step between the hub and the drum.
They didn't do one piece drum/hubs like they did with rotors.

svnt442

I wasn't talking down to you, and I'm sorry you took it that way.

coppercutlass

They usually get seized up. I got some hubs if you happen to need em. I demolished mine trying to seprate them but they came out. then i started picking them up at junkyards. i got 2 sets left.

rustyroger

Possibly someone has put another all in one assembly on previously?.
Do the drums need replacing?. If not and the bearings are in good shape then this might be something to worry about at a later date.
I have known drums that have been a herculean struggle to get off the hub, and British Ford Anglias from 1959-1967 had drums spot welded to the hub. I have seen mechanics smash the drums off because it appears the drum should come off, ending up needing to replace the assembly unnecessarily.


Roger.

joe_padavano

There is no version of the A-body front drums where the hub is an integral part of the drum, period. They are two separate parts. The 67-69 F-body, 68-74 X-body, and 64-66 Jetstar 88 also use these same drums and hubs. In NO CASE is the hub part of the drum. Press the studs out, then push the hub out. There is no other option.

tru-blue 442

It would be nice to see a pic or 2, F/B.

rustyroger

That's not surprising really. I just threw the integral drum/hub out there as a possibility.
Did the different makes under the GM umbrella have unique braking systems like their engines?. It would make a lot of sense, but then so would having a range of GM engines common to all makes.

Roger.

joe_padavano

In the early 1960s, yes, but brake design was consolidated as the years went on. For example, the 61-63 Y-body cars had different brakes (though Buick and Olds were the same). The full size cars through 1970 also had different brakes among the division, both drums and disks. For example, Olds switched to the single piston floating calipers on the full size cars in 1969, but Buick kept the four piston design until 1970. Impala/Caprice used completely different (and smaller) brakes.

Of course, as pointed out above, the 64-72 A-body, 67-69 F-body, and 68-74 X-body cars all used the same brakes and spindles.