I have original hubs and drums on my Model A rear axle. I have lapped the hubs and axle taper with a bit of valve grind paste to tidy things up a bit, no noticeable visual areas of concern after light lapping. I do need to use some tapered shims on the axle as the edge of the brake shoes are rubbing on the drum and/or the drum is rubbing the backing plate. Does most of the wear occur on the interior taper of the hub or on the exterior of the axle taper? Thanks in advance, Phred
I have owned Model A's since 1968 and found that the axle usually get's beat up the most. That's simply because the drum hub has more "mass" than the axle itself. Tapered axle shims are available from Bratton's, part number 6120 at $1.95 a pair.
In 1955-'60, we always cut our own shims from soda and beer cans. But those were the days that TIN cans lined our shelves, now harder to find...it's mostly aluminum now. Pretty sure some Mexican import beer is canned in steel ('tin'), but Bratton's is probably the source...if you can wait...
YES….. a little ‘clearance’, might help. Depending on how bad is the situation. BTW… IF you use shims, the tricky part is to get them to stay in place while assembly. Squeeky clean and patience assembly is helpful. Ive used them. Dont like to but … if you get them properly in place… without damage, they work ! BTW… you asked… IMO, most of axles ARE damages this way….BY LACK OF PROPER TORQUE on axle nut. I find that a LOT of guys do not believe the torque value that MUST be used to get the interference ( axle to drum) necessary to prevent the wear that you are shimming for. If you get NEW axle, new drum, then proper torque… never have this problem ever.
As for where the material goes missing, "Yes". Shimming will help but consider taking some material off of the edge of the shoe if it is a small interference dimension. Torque up the hub tight and if the drum rotates but is just noisy, then you can probably get away with clearencing taking material off the shoes. If you decide to shim, I make a pattern out of paper, using the axle to pattern off of. I then use shim stock that I have purchased from McMaster Carr, but I have that kind of stuff left over from doing precision millwright work. Good luck
Thanks all for your input. My point of curiosity was where the wear occurs on the tapers. I am assuming the axle is steel, perhaps hardened at the taper and outer threads, and the hub is either cast iron or cast steel (not hardened). If this is true, then most of the wear should occur in the internal taper of the hub rather than on the axle taper. In order to get back on the road sooner, I did choose to use to use a shim on the taper rather than clearance thenedge of the brake shoe. Removing the e-brake backing plate to access the shoes requires dealing with my favorite(not) e-brake arm return springs I do torque the axle nut to 100+ lbs and will recheck after some miles as I suspect the shim can "compress" some after initial installation. Peace, Phred
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