mystery brake drum part #

[dlb]

hi guys. new to this forum and chevy's in general. i have some old GM brake drums that i need to replace and am wondering if any experts here might be able to point me in the right direction.

here's the story. my wife bought a home-built horse trailer that i've been fixing up for her. it's been a headache because the spindles and brake stuff are apparently from WWII military surplus, or that's the best guess of the local antique/classic/vintage gurus. i got the brake shoes and cylinders refurbished with no problem but when i took the drums in to be turned, we found that two of them are bent all to hell. there is a raised part # inside the drums which is

GM 6387631

i've searched that part # all over the place but have found no matches. i'm told it might just be a casting #. the drums measure 11" X 2" and are riveted to the hub, which houses the bearings. i'll try to post a few pics to give a better idea.

if anyone can tell me what these are originally off of, where i can find new ones, or any other pertinent info, i'd really appreciate it. i know i could just toss all these old parts and buy new complete replacement stuff but we've already sunk some $$$ into this so far and would prefer to not have to take a few steps backward before moving forward again.

thanks!

[1project2many]

That looks a lot like '40s or early '50s GM cars. Trucks were six lug. Rivets are fairly typical for that time. Sometimes the car and truck drums and hubs could be interchanged so guys would put a car hub on a truck front end so they could use smaller wheels.

All you really need is the bolt spacing, the shoe size, and the drum depth. A good catalog will list the critical drum dimensions for you to compare. The bolt spacing will often help eliminate certain vehicles if you're having trouble but I'd probably gamble and start with a '52 Chevy car.

[mr48chev]

I think 1project2many hit it pretty close.
Is the bolt pattern 5 on 4-3/4 with 7/16 lug bolts?

Also if you need shoes a photo of the shoes and springs that are on it can let someone see if it has Huck or Bendix style brakes on it.

The Huck style have the adjusters on the wheel cylinder while the Bendix have the adjuster at the bottom. 52 and earlier car have the Huck while 53 and later have the Bendix.

[dlb]

oh man, you guys are slick. thank you! i'll take the aforementioned measurements and start looking. the brake shoe adjusters are on the wheel cylinder so i guess it's '52 or earlier, which helps narrow it down. no need for shoes, i got the originals refurbished. these drums are the last part of the horse trailer puzzle so i'm excited to figure it out and put the thing to use.

thanks again, and i'll report back with what i find.

[OrrieG]

Worst case figure out the bolt pattern and inner diameter and shoe width needed. Go to a suspension and brake jobber (if you live in a place large enough to have one) and the counter guy should be able to give you some options.

[mr48chev]

my info says that 51 through 58 passenger cars take a 11x2 brake drum. You would have to knock the rivets out though.

That is if the bolt pattern is 5 on 4-3/4 If it is 5 on 5 they may be Pontiac or Olds. If they are 5 on 5-1/2 or 5 on 4-1/2 they could be Ford. but since they appear to use ball bearings that isn't really likely.

[dlb]

took the measurements, here they are:

lug studs: 7/16"
stud spacing: 5 x 4-3/4"
drum depth: 2"
drum inner diameter: 11"

i called the local auto place that deals in old stuff with those measurements and the info you guys have given. the guy there had tried looking for me a while back but couldn't find anything so he said he wasn't interested in trying again. i'm on the west coast of canada, can you guys suggest any places out here or even down in WA or OR that may be able to help? or better yet, any online catalogues i could check myself?

[OrrieG]

Maybe someone here can recommend a mid 50 chevy car site like this one and you can post your question over there, and maybe find the right part. If you aren't in a hurry I bet you can find one at next years Portland OR Swap Meet! Hope close are you to Vancouver BC? Might find a tri=five chevy club and see if someone has one you can compare yours to?

[G&R's57GMC]

http://www.chevsofthe40s.com

http://www.fillingstation.com

[dwcsr]

If this were mine I might go to the local trailer parts place and buy a new axle and brake kit. With the axle the brake kit can be had for about $500. Then you have late model parts to deal with next time not to mention the add safety.

It may cost half that much to fix up what you have if you can find the parts and you still have way old brakes.

[dlb]

thanks OrrieG and G&R, i will check those links.

dwcsr, if i could go back i would definitely have gone that route for the reasons you mentioned. unfortunately, i had some 'help' that made a rather large mistake in the cost of the refurbishing for the shoes and wheel cylinders, as well as new brake hoses, etc. with how much $$ is sunk into the route we've gone that i would not be able to recoup, i don't want to take a step backward and spend even more $$ on it. i agree that any future parts replacement would be a costly hassle but the trailer is not going to be seeing a lot of use so there is a good chance that these brakes will last the life of the trailer. but oh boy, it really is a cluster**** that i would handle differently if i could redo it. i've learned a lot.

[dwcsr]

Originally Posted by dlb

thanks OrrieG and G&R, i will check those links.

dwcsr, if i could go back i would definitely have gone that route for the reasons you mentioned. unfortunately, i had some 'help' that made a rather large mistake in the cost of the refurbishing for the shoes and wheel cylinders, as well as new brake hoses, etc. with how much $$ is sunk into the route we've gone that i would not be able to recoup, i don't want to take a step backward and spend even more $$ on it. i agree that any future parts replacement would be a costly hassle but the trailer is not going to be seeing a lot of use so there is a good chance that these brakes will last the life of the trailer. but oh boy, it really is a cluster**** that i would handle differently if i could redo it. i've learned a lot.

I understand. Try these guys, they have been in the brake Biz since the 40's

http://www.alretta.com/

[1project2many]

Bendix catalog still lists some of the old stuff. Many of those parts are obsolete but with a number and application you've got a better chance.
http://www.bendixcatalog.com/PartDet...e=Brake%20Drum

[dlb]

just found a guy who recognized these drums. he says they are 1949-50 chevy car front drums. said he can get good used drums for $150/each, and hubs for $150/each as well. if anyone else is interested, his name is bob and his website is

http://adlersantiqueautos.com/

looks like he primarily deals in old chevy trucks but seems knowledgeable about other stuff too.

i will have to see exactly what i need to replace and if it will be cheaper to just go with new axles at this point like dwcsr mentioned, but many thanks to everyone here for all the help in figuring this puzzle out. you guys make this forum an excellent resource.

david

[OrrieG]

I posted on local CL to see if someone has a couple sitting in his back yard around here. or do you need 4??

[sweet70beast]

Originally Posted by dlb

just found a guy who recognized these drums. he says they are 1949-50 chevy car front drums.

Just saw this post but he is right. 1947-8 and earlier cars and trucks were 6 lug. The grooves around the outside of the drums are huck style brakes, bendix style drums are smooth. Cars and 1\2 ton and maybe 3\4 tons got bendix in 51, 1 tons and bigger kept the huck style a little longer.

[dlb]

just two--thanks very much OrrieG, that's above and beyond of you! i just did the same thing. fingers crossed.

[OrrieG]

I will be going over to Eugene sometime the first couple of weeks of Sept. I will call my gearhead buddy over there and see if he can find something. He lives about 10 minutes from an vintage wrecking yard.

[OrrieG]

Originally Posted by dlb

just two--thanks very much OrrieG, that's above and beyond of you! i just did the same thing. fingers crossed.

you have a PM, good news.

[nvrdone]

Call All American Classic in Vancouver WA - 360-254-8850.
They may be able to identify it & possibly supply new drums. Also consider using Classic Parts roller bearing conversion.
Good luck