My f-250/350 frankentruck needed new brake cylinders and as it turned out, new shoes and drum on the passenger side. It was all siezed up and after a few shots with the sledge the drum fractured clean in 2. It was fun. I thought getting a new drum would be no big deal but it seems I was wrong. My old drum measures 12 & 1/8" diameter by 5 1/4" tall and the area for shoe contact seems to be 3 1/2". The shoes that were on there were 3". It is a 1 ton dually - but originally was a 3/4 ton single. I tried the 12 X 3" and it wouldn't go over the shoes even with the spacer nut backed all the way down and the parking brake disconnected. I got a 12 1/8" (not sure if they may have given me the one for 3 1/2" shoes) which is supposed to be for dual rear wheels but its several inches too tall and rides on the backer plate.
Anyone run up against this before? I think I'm looking for a 12 1/8" by 3" with a total height of 5 1/4" for a dually. But I'm not sure since the area of the old drum for shoe contact measures 3 1/2". Then I thought maybe I need a 12 1/8" by 3 1/2" for single rear wheel but so far I've been led to believe that doesn't exist.
As you may have picked up, I'm not sure what rear end I have in this truck since the previous owner did the rear end swap. The truck is titled f-250, 1993 but those are just words on paper.
Anyone have any tips for me on how to figure out what drum I need? I'm completely stuck.

 

First off, I think you need to figure out for sure which axle you have. I know that a 93 F250 is supposed to have a Sterling 10.25 full float axle, and I believe an F350 DRW should also use a Sterling 10.25. However, IIRC, Dana 80 axles were also used in F350s during some model years (I don't know off of the top of my head which years), so I could be that you're looking for drums from a different year/model of truck.

A quick search of Google tells me that a Sterling 10.25 is going to have a 12 bolt cover, while the Dana 80 is going to be a 10 bolt cover.

 

Dana = filler plug on rear cover
Sterling = filler plug on drivers front side of pumpkin casting.

What's to keep you from taking the drivers side drum in to the parts place and matching it up?

 

Best idea I've heard...

 

I followed ArdWrknTrk's advice and brought the "good" drum into my parts shop and they measured it which led a lot of head scratching. Turns out these are custom drums. And when I say custom, think duct tape. I'm not sure why the previous owner choose to go this route but seems that he took the drums for a single wheel rear end (12" diameter) and had them turned out to accommodate the 12 1/8" diameter of the shoes on this axle.
We only concluded this after we had run through each and every resource for locating a 12 1/8" X 5.25" drum - and realized they don't exist.
The solution? Take a brand new 12" X 5.25" and turn it till it is 12 1/8". I may have lost tens of thousands of miles of life on the new drum but I prefer to think of having lightened it for racing. At least I'm back on the road.
I'm guessing a different wheel carrier would allow the correct drums for a dually to fit, and at some point I'd like to put the correct drums on, will I need new wheel carriers or something else?

 

ya different backing plates and then go from there, new is the only way to go there

 

you may also wanna take a look a a drum for a f350 or e350 cab and chassis they are are a little different than pickup stuff specially if it looks like spring perches have been messed with