The Stovebolt Site Forums The Shop Area Driveline 52 1/2 ton max drum diameter

Does anyone have the max allowable diameter for the front brake drums on a 1952 1/2 ton. The only thing I show in my 1951 manual is that when machining the drums to oversize, the shoes must be over sized. There are no max diameter tolerances stamped on the drums themselves.

Should be discarded past 11.094~11.095 as I recall. It was stamped on most drums...except for some aftermarket drums.
Jon

If someone could scan and email this info from a publication this would be a big help. I'm needing it for a safety inspection and the mechanic doing the inspection won't sign off on it until he is assured that the drums have not been machined past the limits. The drums on the truck do not have the max limit stamped into them. I also have a 1951 1/2 ton parts truck and it's drums are not stamped as well.

I do not know the answer, but here are some specs (that may or may not be helpful):

standard diameter: 11"
allowable over-bore: 0.060"

That does not seem like a lot of allowable over-bore?

0.060" is pretty much the standard max overbore on drums on cars and most light truck, with around 0.090" being the discard.

I checked again to be certain. One drum is hard to read and looks like 11.09?. The most legible drum says discard pt. 11.080. Here is an image:
http://s1154.photobucket.com/user/JonGoodman/media/MVC-764F.jpg.html
Hope it is helpful. I have some new ones, but I'd have to get in the attic and am too tired for that tonight.
Jon

Thanks Jon, that's along the lines of what I'm looking for. Ideally though I need something in print that I can take to the mechanic.
Jon if you could take a pic of the entire drum showing the bolt pattern giving a possible and plausible reference that this is a drum from a similar truck I may be able to use this.
I'm getting lots of grief from the mechanic for proper authentication that things meet spec and have the proper markings or documentation.
Another point of grief was that the door glass had no markings stating that it was safety glass. I contacted GM and received a letter that safety glass wasn't even a requirement till 1955 though they did install safety glass prior to that. That wasn't good enough so then asked a local glass shop to check the glass and provide a letter as to what was indeed in the truck.
It's been a bit of a gong show.

I think I would looking for a different mechanic, as it sounds like this one is giving you the runaround. If he was any sort of real mechanic, he should have the specs on hand, or at least know where to source them without you having to provide them.

Oh that I could go backwards. Problem is I have to pay the gov't so that I have their permission to get an out of province inspection. I then take this piece of paper to an authorized shop enabled to do these inspections. They then take this paper, note the authorization, throw the authorization away, do an inspection noting all deficiencies and send to the DOT. So now I have to complete all deficiencies, and have reinspected. The mechanic will then fill out a form that the DOT and I receive. If the DOT does not release the truck via the registry system the truck will not be able to be licensed.
As to me supplying all the specs, that has me in a foul mood. Truck has to meet standards of the time yet they don't have them and want me to. Grrrrrr.
So this is why I need some form of documentation. If I'm unable I'm going to be looking for some front brake drums and actually started looking today just in case.
Thanks for the help thus far guys, much appreciated.

Well, okay...here is an image of the brake drum I mentioned:
http://s1154.photobucket.com/user/JonGoodman/media/MVC-766F.jpg.html

And here is an image of the 1952 pickup from which that exact brake drum came:
http://s1154.photobucket.com/user/JonGoodman/media/truck%20March.jpg.html

One way to tell if unlabeled glass is safety laminated is to look at a reflection of your wristwatch at an angle in the glass. If you see two images close together...it is a very good likelihood you have laminated glass. You can occasionally see two images in a thick piece of tempered glass, but it isn't too common.

Hope this is helpful.
Jon

I agree with Longbox. What a bunch of nonsense!

Oh I meant to mention that if this is a 1/2 Ton, new drums can be bought easily.

All good guys, found a set of new ones and I'll just put those on. Should make all needy depts happy and I can stick Alberta plates on it.