Rear Brake Drum Dilemma

[roger55]

Originally Posted by jtrichard

any numbers on your old drums? besides the max od? pic maybe?

[slorio]

Roger55:
A few things. These drums have been on my GMC for about 8 years now with no problems. Rock Auto has them for $64 if you want to order from them, I am sure they could be returned to Rock with the only out of pocket for the shipping. Here are the specs:

http://www.rockauto.com/catalog/moreinfo.php?pk=427143

The lip on the back of the drums actually extends past the backing plate. The drums are for a 11X2" brakes which is what you have. Also, the application that they are for is the later model Chevy/GMC's 4X4's that, you guessed it, used Dana 44's on their front axles.

Don't know if that convinced you, but that is all I can offer.
Regards,
Steve

[66customcamper]

Might try this place:

http://www.allamericanclassics.com/

That's where I found rear drums for my '66, though it's been years ago. They've got quite the collection.

[roger55]

Originally Posted by slorio

Roger55:
The lip on the back of the drums actually extends past the backing plate. The drums are for a 11X2" brakes which is what you have. Also, the application that they are for is the later model Chevy/GMC's 4X4's that, you guessed it, used Dana 44's on their front axles.

Thanks Steve, I appreciate your help.

I think I can get my O'Reilly's to order a set of those same drums and I can inspect them. That way I'm not out a dime if they don't fit.
Plus they are $50.99. Strange, usually Rock Auto is cheapest.

Since the lip extends over the backing plate, it wouldn't allow you to actually see if the brake shoe extended past the friction surface. Are you absolutely sure yours doesn't do this? Have you pulled those drums off since installing them 8 years ago?

I don't mean to be doubting you while you're helping me like this but I'm just trying to cover all the bases with the conflicting info.

Roger

[gimmy 64]

ihave a 64 gmc I went through this same thing. found out the drums for 72 chevy blazer 4 wheel drive works. these have been on my truck for about 2 years. $50 bucks at autozone. I did not have to drill the lug holes either?

[roger55]

Originally Posted by gimmy 64

ihave a 64 gmc I went through this same thing. found out the drums for 72 chevy blazer 4 wheel drive works. these have been on my truck for about 2 years. $50 bucks at autozone. I did not have to drill the lug holes either?

Leaf or coil springs?

[gimmy 64]

leaf springs

[roger55]

Originally Posted by gimmy 64

leaf springs

The '72 Blazer is also the 2067 drum. So add you to the list of success with that one.
Confused why yours didn't need the lug holes made bigger though. Maybe your lug studs where changed out with slightly different ones.
The factory lug studs shoulders extend out the holes just a tad.

[63burban]

Did you try a front drum ?

http://www.napaonline.com/Catalog/Ca...071_0325246619


http://www.autozone.com/autozone/par...=21774_0_9519_

[roger55]

Originally Posted by 63burban

Did you try a front drum ?
http://www.napaonline.com/Catalog/Ca...071_0325246619
http://www.autozone.com/autozone/par...=21774_0_9519_

That's the drum that fits the coil spring version and is also a Raybestos 2005

Yes, I tried one and it is too narrow and doesn't fit.

[gimmy 64]

I believe that they were original drums. they were original to the dana 44 ?

[roger55]

Originally Posted by gimmy 64

I believe that they were original drums. they were original to the dana 44 ?

Not sure I understand your question here.
Post #26 shows one of my original Dana 44 drums.

[roger55]

I'm getting ready to order drums and talk to the machine shop.

I want to look at the 2067DGS later model 4WD drum and the '74 Wagoneer drum.

After more studying and measuring, I found there is one measurement that is crucial. The distance from the inside face of the drum that contacts the axle flange to the outer edge of the friction surface cannot be less than 3 1/16".

If anyone wants to measure the 2067DGS they have for that measurement, it would save me a little time and trouble. If anyone is running that drum and that measurement is less than 3 1/16", I suspect the shoe is hanging out the back of the drum some.

[jtrichard]

roger the measurement you have pictured the height is about 3.250 the ones you say it takes are 3.45 almost 1/4" higher .....the jeep ones with the smaller center hole are 3.35 high you need to check how far back from the axle flange face to the brake shoes and then how deep the inside of the jeep drums are and how deep the braking surface is ..if the shoes will not hit the inside of the drum web they should work for you ... if you need to the machine shop could whack off that extra .100 for clearance on the backing plate ... i hope you can follow what i am trying to say

[roger55]

Originally Posted by jtrichard

roger the measurement you have pictured the height is about 3.250 the ones you say it takes are 3.45 almost 1/4" higher .....the jeep ones with the smaller center hole are 3.35 high you need to check how far back from the axle flange face to the brake shoes and then how deep the inside of the jeep drums are and how deep the braking surface is ..if the shoes will not hit the inside of the drum web they should work for you ... if you need to the machine shop could whack off that extra .100 for clearance on the backing plate ... i hope you can follow what i am trying to say

I got you.

One thing though. Take a close look at the jeep drum again and you can see a very slight raised edge at the center hole. When the hole is machined out, that raised edge will come off. That might make it closer to the 3.25" of my original.
I'm thinking these Jeep drums will work at this point.

I'm still confused about the 2067DGS ones though.

In any case, I'm going to need to get the lug holes drilled out to .58". I don't have a bit that size but I assume the machine shop will have that.

[jtrichard]

the 71 to 75 chevy/gmc 4x4s are 4" high that's what NAPA shows,,... homo depot has 9/16 drill bit $15 that's .5625" im sure that would work if the machine shop don't have one but i bet they do

[roger55]

Originally Posted by jtrichard

the 71 to 75 chevy/gmc 4x4s are 4" high thats what NAPA shows

Yes but the 4" includes the fin overhang.

Again, the crucial measurement is the distance from the inside of the drum where It mates to the axle flange to the end of the friction surface. That has to be at least 3 1/16" but not wide enough to hit the backing plate.

A couple of guys here are saying the 2067DGS does work. But a guy from another site said they don't because the friction surface is too short.

I have a pretty good relationship with my local O'Reilly's. Maybe I'll see if they will order in both a set of the Jeep drums and a set of the 2067DGS and not have them charge me for what I don't buy. I think I'll try to do that Monday or Tuesday but I want to call the machine shop first and make sure he can do what I'll need done.

[jtrichard]

you have to watch out if it goes over 3-1/6" that not only will it hit the backing plate (that can be trimmed) but you could start hitting the shoes on the web... the ones that say it works probably have some shoe outside the drum

[roger55]

Originally Posted by jtrichard

you have to watch out if it goes over 3-1/6" that not only will it hit the backing plate (that can be trimmed) but you could start hitting the shoes on the web... the ones that say it works probably have some shoe outside the drum

Agree.
Unless there is some friction surface width variance in the different manufacturers of the 2067DGS.

[jtrichard]

i still think the jeep is your best bet just look at that extra ring that goes around the backing plate you may have to take some of that off to clear the plate as your old drums have.... just don't take any more than you have to to get clearance Clarance lol... that extra ring keeps the drum from expanding the more meat the merrier

[roger55]

Like I said, I had O'Reilly's order me in a pair of the 2067DGS and a pair of the Wagonneer drums. On the 2067DGS the distance from the axle flange surface to the edge of the friction surface was 2 15/16". That's just a little short. Using that drum, the brake shoe would extend 1/16" to 1/8" past the edge of the friction surface.
I expect those that are using this drum have that situation.

The Wagonneer drum is 3 3/16" from the axle flange surface to the edge of the friction surface. This is 1/8" more than my stock drum has but appears it will not hit the backing plate.

So, I bought the Wagonneer drums and will take them to the machine shop and have the center holes and lug holes enlarged. I did call him last week and he said he could do this no problem.

[jtrichard]

did you check to see what the measurement is from the inside mounting surface of the drum to the inter braking surface is compared to you ORG. ones? since you have 1/8 in. diff. to the outer if it tries to hit the shoes on the inside you could have the machine shop make a shim/spacer out of your old drums that would make up about 1/8"

[roger55]

Originally Posted by jtrichard

did you check to see what the measurement is from the inside mounting surface of the drum to the inter braking surface is compared to you ORG. ones? since you have 1/8 in. diff. to the outer if it tries to hit the shoes on the inside you could have the machine shop make a shim/spacer out of your old drums that would make up about 1/8"

Not a problem there at all. The total friction surface width is well over 2 1/2" and the brake shoes are 2".

[NEWFISHER]

sometimes I get so focused on getting something done, the simple things slip through.

Is this a 100% restoration rig? If not why not change the backing plates, hardware ,shoes and available drums?

Rear disc?

I hope you figure it out, its been awhile and your missing some good drive time

[roger55]

Originally Posted by NEWFISHER

sometimes I get so focused on getting something done, the simple things slip through.
Is this a 100% restoration rig? If not why not change the backing plates, hardware ,shoes and available drums? Rear disc?
I hope you figure it out, its been awhile and your missing some good drive time

I addressed the backing plate idea on the first page.
I've pretty much got this issue licked now. It just took me some time searching forums fishing for ideas. The Wagoneer drum looks like it's going to work out fine and with a minimal cost too. I got those drums today at O'Rielly's for $28.99 a piece and I'm guessing the machine work will cost me $50 to $60. The last time the drums were available for this GMC rear, they cost over $100 a piece. And btw, I've got this '65 GMC rear under my '57 Chevy 3200 pickup.

I'm not losing any time driving. I've got the cab off the frame right now and won't be ready for paint until later this year.