Rear brake drums for 1966

[Rob Dale]

Hi,

I am Rob from OKC. I am working on my 1966 GMC 1000 and I am having a hard time finding the correct 6 lug rear brake drums. I keep getting ones from the local parts stores that are for Chevy's which are flat in the center like the front hubs, but the ones from my truck have a rise in the center. Anyone know where I can locate these drums?

Thanks

[sclor]

I have two part numbers you can try for rear 6 lug brake drums. The first is a Wagner BD 60089. The second is Allsafe 2067 DGS.

I used the Allsafe from Autozone. It is for a later model (I think 67-72) truck with 4 wheel drive. It has fins on the outside unlike the original that is smooth. The only modification that I had to make was to drill the 6 lug holes from 1/2" to 9/16" so that the drum would fit on the shoulders on the rear lugs like the original. This drum had the right offset unlike the Chivy drums.

The Wagner was a number that I got from another member of the 6066gmcguy.org site. I haven't used that one, but was told it was a direct match to the original (a bit pricey, though is what I remember).

I hope this helps with those looking for rear 6 lug drums.

Regards,

Steve
New Orleans

[Jeannie]

Welcome to the 60-66 GMC Club Rob.

I have replied to your PM but I will post the information here as well for other members.

For brake drums you can try the brand Raybestos part number 2067 from Autozone. They come drilled at 1/2" instead of 9/16". You will need to drill the lug holes out to 9/16".

Duralast part number 8821 is also reported to work if you are unable to find Raybestos drums.

Have a great day,

-Jeannie

6066 GMC Club

[Rob Dale]

Thanks for info, will bee hitting the parts store tonight

[Pops]

I'd like to hop in with a question if you don't mind. I have a 66 half ton light duty (I1000) with dana 44/354. The rear brake pads measure about 1 7/8 inches. There is about 1/4 inch of outer edge of drum that has no contact with pad. Is this normal? I haven't dealt with d-brakes in decades. Brakes work ok.

[sclor]

Pops:
No, that is not normal. That happens when someone installs the drums meant for a Chevy on a GMC. Those drums would fit the front of your GMC as well, but they are not appropriate for the rear. Check the part numbers listed above and you will find that they have an additional quarter inch of depth (I think they measure 3.54") that would correct what you are seeing in the rear.
Regards,
Steve
New Orleans

[Pops]

just to make sure I'm clear, my brake pads are about 2 inches wide, the inner surface of my drums are about two and a half inches wide. the drum fits nicely against the hub. Therefore, if I got a wider drum, it would look even more inappropriate. I think. My drum extends about a half inch wider than the shoe. I believe normal but just checking.

[Pops]

Could my axle be chevy? Its a Dana 44 with leaf springs so I never thought anything other than gmc. I have read that 373 were more of a chevy rear. One last point, I could be riding on a 70's suspension. Not the original frame.

[sclor]

Pops:
Why not post a picture of your issue and we can take it from there?
Regards,
Steve
New Orleans

[Pops]

Dear sclor when I figure out how to post pictures I will be post a lot. Im a picture dependent mechanic lol. I pulled rear wheel and did some measuring. For openers, my drum is approximately 3 1/2" tall when placed on floor. The center of drum raises higher than sides. It looks old school; not finned. Even has groves from shoe rivets. Finally, it does not look or measure as front drum.
Ive taken pics from every angle to show others. Two bolt wheel cylinder, emergency brake hook up, etc.