Apologies in advance for the gigantovision photos. I haven't cracked the code for Macintosh/Photoshop.
I asked this question a couple of weeks ago, and got some good replies. One reply pointed out that, if the hub goes too far onto
the axle, you may bottom the axle nut onto the end of the threads before getting the hub tight. Not good. So I made this
simple check on both axles before installing wheels for good:
First photo showing nut bottomed on end of threads without wheel.
Second photo showing same measurement with wheel installed.
By subtracting one measurement from the other I could determine how close the nut was to bottoming on the threads
with the wheel installed. Turned out one side was very near bottoming and thus needed a shim. Other side was fine.
How close is the hub to the Axle grease seal? You do not want the hub to contact the seal.
John pretty much has the right idea. As long as nothing is rubbing anywhere, you don't need shims. If you simply run out of threads, I would, (and I do), use a washer. Going a step further, if something IS rubbing, you still don't need shims, you need a better hub and/or axle shaft. But... some folks use shims. I get it, it's fast, easy & cheap. Just be sure to regularly check the axle nut for tightness as the slightest movement will wear away at the shim and things will get loose again, fast. Plus, pieces of the shim will migrate up the shaft and cut your axle seal to pieces.
John S, I'm not sure how close the hub is to the grease seal, except to say that there is no evidence of rubbing. Sure would like to know for certain. My X-ray vision is sorta like my hearing -- not what it used to be.
Jerry O, I bought a nice hub from Chaffin's, and then John Semprez gave me one of his extras. In both cases the replacement hubs had a larger radius where the flange meets the body. They wouldn't fit into the bore of my wheel. I'm not sure when Ford increased the hub radius, but my car is a 1912. Assuming the bigger radius began soon after my car was built, that means 99% of the hubs out there won't fit. So I gave up looking and put my old hub back in the wheel.
According to the Encyclopedia, the tapered axle design did not change from itsí introduction in October 1910 thru the end of production. I rather suspect your axles are not correct.
Tony, I believe Dick is talking about the fit of the hub within the spokes, not the fit of the hub on the axle shaft. Dick, the thickness of the hub in relation to the length of threads left exposed when the hub is seated should be measurable to tell how far the hub is seating on the axle.
You can use some modeling clay or something similar to to "see" the clearance between the hub and the seal. You can also use the same technique between the brake drum bolts and the parking brake bits. I was helping John S mount a radiator on a TT this afternoon.
Guess I wasn't clear on the way that late wheel hubs don't fit on early wheels.
Here we go with another gigantovision photo. The hub with yellow primer is a late type with large radius. The dirty hub is out of my '12 wheel.
Here is what the hole in the center of the wheel looks like. Radius cut into spokes fits perfectly to hub radius, so a fat radius hub won't fit in an early wheel.
Dick, When I rebuilt the rear on my late 1911 ( tapered axles ) 25 years ago,the inside of the hub was rubbing the brake shoe a little on the right wheel. I installed the axle shims that lang's sells ( part # 2505SH )They work well. I check and tighten the wheels a couple times a year.I have had to replace the shims twice.