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Does anyone know if the hub styles changed from 1931/1932 on the rear?

Yes, If you measure from the area where the wheel seats to the end of
the hub the AA is about 2" and the BB is about 3 9/16"

Are the hubs interchangeable

How about the early 1930 to the later 30/31? I found some Hubs that appear to be similar to the 1930 style hubs but seem to have additional flange surface where the wheel mounts.

Pages 418 and 529 of the Service Bulletins have information on the difference in hubs.

Bob

I am sorry but I do not own a copy of the ford service bulletins. I bought two rear hubs today and when I got them home I found that the hub was a little different than the hubs I pulled off my early thirty. The gentleman I bought them from believed they came from a 1931 AA truck. Hubs are in extremely good shape and complete with bearings, new brakes (including emergency), backing plates and all brake hardware. The drums had heavy grease wiped around the inside to keep the surface from rusting. I measured everything between the two hubs and all measurements were almost identical (within a 1/16 of an inch. The two hubs had identical hub caps like my early thirty. The only two differences that I found was the hub I pulled off my truck had the outside of the bearing seal casting machined up about 1/2 inch from the end. They only took about 1/4 in off almost like they were going to put a seal around the bearing holder in the back vs. inside. The two new hubs are cast all the way to the end and have not been machined. The second difference is that my hub I took off has only a small area around each lug and is open between the lugs. The two new hubs have a flat flange all the way around with a grove in the middle that holds the lug flange. The actual brake drum on the two new ones seams to be forged steel and my old one looks to be Cast. I am hoping I can use these new hubs on my early 30 as I may need to cut one of the rear of as I have been unsuccessful in removing it. I have not given up yet but if new hubs work I may cut off this weekend. I needed to get new brakes for back including emergency brakes and was able to buy the complete sets for about what relining the brake drums would have cost. I will post some pictures tomorrow when I can resize them at work. Thanks

The Service Bulletins say "On a few of the early 1930 single rear wheel AA trucks, a scalloped design
hub was used". Sounds like what you may have.

Bob

The Service Bulletins are invaluable. I have a complete original set as well as the reprints. Every Model A-AA er should at least have the reprinted version.

here is some pictures of the rear passenger side hub from my early thirty. Notice the machining on the bearing holder end.

Here is some pictures of the hubs I bought. Are they OK to use on my early 30?

The first picture looks like the scalloped hub with removeable bearing race and a cast
iron brake drum. The last pictures look like later hub but the picture is not clear enough
to tell if it is a cast iron drum. Measure the distance between where the drum mounts
and where the wheel mounts, it should be either 7/8" or 1 5/8". Take care of those cast
iron drums they are hard to come by.

Bob

I believe the ones coming off my truck are cast and the ones I bought are not ( they looked stamped). Did you notice the machined section on back of first hub? This is the one with bearing removed. Why would this have been done? Can I use the later hub on same truck?

The later hub and drum assembly (with the disk for the wheel backup) is AA-1113-F RH and AA-1114-F LH. These hub/drum assemblies can be used on any 1930-1931 AA.

The scallop design hubs/drum assemblies were AA-1113-D RH and AA-1114-D LH. These were replaced in production with the "F" assemblies.

Original drums were steel.

Thanks Neil. If original drums were steel - are the cast drums after market?

s147881 wrote:Thanks Neil. If original drums were steel - are the cast drums after market?

As far as I know, cast iron drums were made by Ford for some period of time after 1931. I don't know when this started or for how long. I would think one would want all steel or all cast iron for a given AA.