My question is probably beyond most of you asking why I would possibly be interested in doing this with so many early banjo rear ends available, but hear me out.... I bought a nice factory 46-48 open drive 3:78 rear to possibly use in a 1930 A' coupe - yes, I knew it was too wide but there's always the challenge. The 40 rear is close to the width of a model A and the 46 is too wide. I could use 40 length axles and narrow the bells of the 46, which have already had the parallel spring pads removed and they are VERY nice condition. How would you approach mounting the bells in the lathe, and how would you cut the ends off - remove the excess - and then reweld the ends back onto the housings at the length of a 40 style axle bell. It had all new bearings and was set up very well, and the only thing missing was the seal for the open drive cover on the pinions shaft. Interested in your approach to my questions. Thanks
When I was going to use the Banjo in my '28 Tudor it was set up to real close to the stock A width. It has '36 bells, a open '47 truck center and '41 axles. Are you going to use the transverse stock A style spring?
Hot Rod Works in Boise does that but that's a long way from you and buying a pair outright would cost a fortune not to mention shipping cost. '34 -'36 rears are a good fit for the Model A.
Don't know about shortening but I used a '39 rear (and juice brakes) on my '29 roadster. The fit was excellent.
I can't understand why you would want to spend hundreds to narrow a 48 rear to 40 width, when you could buy the parts for the swap and do it in a weekend. If you had to hire the machine work, it would probably cost hundreds. The 40 rearend would probably cost $100 complete.
I once cut the tube up where it meets the bell, on a 35 axle, and welded on model A tubes to get the A spring hangers, and later diff center. Since I could do it at home, and had the parts in stock it was not a big deal. But, what did I gain? not much
I have done this on '36 bells and at the same time installed 9" Ford bearing housings. You would need a boring bar (to keep the housing true when welding) and bearing slugs. Since I wasn't going to do alot of these I made the slugs out of Aluminum. I never used the lathe except to make the bearing slugs for the bearing housings and the banjoe rear. Having an extra center section helps.
While I'm not a big fan of the tapered/keyed axles, it can be done. You can cut the tube on a lathe with a parting tool. If you turn them round where you will reweld them, before cutting them off, you can use that to pilot the housing end. If you try to simply butt weld them on, you need a fixture to hold the alignment. The axle tubes (trumpets) are not round!
Steve to do any work on the banjo housings its obviously not a simple task. I use my Southbend lath to modify housings its a 16 inch swing by 6 foot long bed. The fixtures to hold the banjo housing and spindle end are custom made. The spring mount is a big issue since it sticks out a lot. For the effort involved its a much better idea to get the 40 axle housings and axles. The carrier assembly and new bearings from the 46 rear are the same as the 40 so only the carrier races from the 46 housing need to be removed and installed in the 40 housings if they are new. The spider gears from the 46 will work with the 40 axles as long as the 40 axle tooth count is the same as the 46 simple change of gears and axles no set up required. Setting the rear up is extremely easy measure the thickness of the axle housing gaskets from the 46 and set up the new housings with that thickness gasket from there check back lash and how much drag the carrier bearigns have its oveall easy stuff to do. . Its a lot less money and lots less hassle using the 40 parts. Check on the Ford barn post what your looking for I bet you will find good stuff without much trouble. Ronnieroadster