just installed new wheel seals, brake cyl, brake shoes, axle bearings. When I assembled I found the Left rear brake drum stands off the backing plate further than it should. The right side is fine. The brake shoes are riding right on the edge of the drum on the left side.

The brakes were all disassembled and in boxes when we bought the truck. I can tell that it was like this before by the wear pattern of the brake drum.

I have pulled it back apart and double checked my assy. I have checked the axle length, bearing position on the axle, compared old vs new brg and retainers, compared brake shoes, I even removed the new wheel seal to be certain the brg retainer was not hitting the seal although measurements verified it was not.

I have put a glob of heavy wheel brg grease on the end of the axle shaft and installed it in the rear end, pulled it out to see if the grease was compressed or stuck to something inside the rear end. When I pulled it back out the grease was still there. And yes I did try changing the right to left axle and drum. I pulled the left rear backing plate laid it on the floor and measured from the floor to the outside edge of the plate at different places around the circumference. These measurements were very close all the around the plate.

When the axle is in position the bearing protrudes from the housing about an 1/8". The backing plate rests on the edge of the brg to center it in position while you tighten it to the axle hsg.

Everything looks correct to me but the position of the drum.

After spending all this time checking and rechecking this occurred to me, what if someone installed a front drum on the rear axle stuck the wheel on and torqued it down, would this force the backing plate in and bend it evenly around the circumference of the plate. I would think the cast drum would break first before this would happen however it is the only solution I can come up with.

Anybody seen this problem before! I would appreciate your input. Thanks Jim

NOTE:
The first brake drum pic is the right side, the second is the left side. The rusted groove should be about to the backing plate.

 

OK, just a shot in the dark here... when you removed the drums, did they still have the small bolts holding then to the axle? If so, could you have put those bolts back in the axle?

 

No I did not even know they used them. I noticed the smaller set of holes but paid no attention to them. When we bought the truck all of the brake stuff was removed and in individual boxes e.g. LR,RR, RF, LF. They just had the wheels and drums stuck on and a couple of lugs to roll it upon the trailer. I am not sure if those bolts would be in the way of the aftermarket wheels I will have to ck that out.

 

OK, well did you check to see if the bolts may have been left in the axle by the PO? We've discussed this item before and concluded that they are not really necessary and yes they would interfere with a lot of the aftermarket wheels.

 

when the drums go on they all the way against the axle Pic included

Note one axle missing wheel stud, will get that on our next order
local auto stores do not have the correct stud.

 

It sounds like one of the new bearings isn't seated all the way, either onto the axle or into the housing. When you switched axles side-to-side, did the problem follow the axle, or stay on the same side? If it followed, then it's the bearing on the axle, if it didn't, then it's the bearing to housing.

 

Jim, that drum does not look like it's all the way on. If you compare your pictures with mine, you can see that my drum is in further than yours. Yours is even with the slot in the axle, and mine goes past that.

 

yes I see that, That's is odd?? But this I know the inside of the drum is right against the face of the axle. I just went out and looked again. Also the right side and the left side look the same.
It sure has me puzzled. I swear the only thing I can think of is that someone forced a "deeper " front brake drum onto the rear and bent the plate inward.

 

also note for comparison of my pics that show the face of the drums and the axle slots that my right drum has 5 studs and the Left has 4 studs.

 

Check this page on Rock Auto, there are height specs for the front and rear drum that may help.
https://www.rockauto.com/

 

Could you lay a straight edge across the back of each backing plate and measure to the center, close to where it bolts to the axle housing, to see if one of them is bent?

 

I don't think you could bend a backing plate, they are stout.

 

thanks guys for your input.
I will take both backing plates off Monday and lay them down where I have no interference and lay a straight edge across them and get a comparison.

The problem has to be the backing plate. on the left side, it has to be bent or the wrong one. I do agree with ross It would take tons to bend one but I don't know what else it could be. I could see a novice installing the front drum which is wider sticking a tire on it and running it. It would shove the backing plate inward I think. I am going out to the garage now ad see if it would be possible. I will report my findings.

 

Could you have a different year backing plate? According to the Ford Truck Parts Catalogs I have the 48-56 rear brakes on F-1 and F-100 pickups are 11 in diameter by 2 inch width. The 57-63 F-100 rear brakes are 11 inch diameter by 1.75 inch width.

Edit: I originally stated the 1.75 width brakes were 57-53 as noticed by Albuq F-1. I corrected it to 57-63. I apologize for any confusion this may have caused.

 

I think you mean, 57 -63? My recollection is they were still 2", then in '64 they went to 2-1/4".