rear hub issue on my U model

[deluxe-styling]

I have a '46 U model and when I ease on the rear brake I get an on-off-on type action. I guess the brake hub is warped out of shape or has a high spot. Sounds possible or am I missing something more obvious?
I have known old cars to have warped hubs along with the same issues. Anyone have experience of this?

[Robert Luland]

Try relining the shoe before ya hang the brake drum. Bob L

[deluxe-styling]

I've just pulled the rear wheel and hub off. Here's what I found. New hub and shoes but don't like the look of the backplate.

[deluxe-styling]

Looks like the hub is out of true. What does anyone think?





I assembled the brake in the wheel and clamped the spindle in a vice. When I spun it you can feel a tight spot just the same as on the bike.
I then applied a dust of matt black spray paint onto the hub surface and when spun again the brake lining took the paint off in the exact area where the marks are.
This I'd say is proof the hub is out of true so I'm going for a new one. Any thoughts?

[diesel55]

Hello could be the rewelded center on the 1st picture /or possibly the repop brake shoes also looks like the wrong brake springs. looks like a coobled together assemby

[Robert Luland]

First off the brake drum and shoes are after market but no big deal. The problem comes in to play with the backing plate. In order for that item to fatigue and crack it had to be moving in and out. By the look of the brake drum it's not tracking straight. Unless the guy that welded it up made sure it was 100% flat you will end up with the problem your having. I have an extra backing plate here if your interested. Bob L

[deluxe-styling]

Thanks diesel.
I'm with you on not liking the re-welded parts. Maybe a whole new rear brake set up wouldn't be a bad thing! Might start with a hub first and see how it goes.
I don't think you could warp one especially when you think of the amount of heat needed. More like it was warped from new. Could just be a poorly made hub? Anyone heard of this before with re-manufactured hubs?

[Rubone]

Tip number one,
Do not confuse a hub with a brake drum. Two different animals, and mixing terminology will get you more confusing info than you need!
The center of the wheel is the hub. The brake outer housing is a drum.
Yours is made up of a bunch of mismatched reworked parts, so getting a good brake action will be difficult at best. Check the drum for roundness, the shoes for concentricity, the backing plate for flatness and parallelism, and you will find your problem!
Robbie

[diesel55]

Sorry to be frank Bob the repo crap has a lot to do with this mans problem.if the rest of the parts involved are any thing at all like the pictures i see hub/drum/ shoes face plate and hardware .he has a major problem

[deluxe-styling]

Sorry for the wrong terminology, that's crossing over with car stuff and I'm British!
Thanks for everyone's input. I'll do those checks.

[Sargehere]

If you want to be technically correct, the brake "drum" is called a "brake shell" in all of the Harley parts catalogs, not "drum" at all. It really is important, in most cases, to own a reprint of a factory "Spare Parts" book for your model of Harley (they're basically "all" available), and refer to it often when writing here; that way, everyone has the same references when delving into problems like this. "Brake drum " is so universally understood that it doesn't matter in this case, but can u name a part, number 4359-29? (66010-29 after the 1951 parts change-over) and compare that with PN 66202-29.

[Robert Luland]

Ok, so the whole thing is a butchered mess. I was trying to be some what kind. You know? Those AMCA family values!

[Sargehere]

It might pay you to check Shop Dope 157A, dated April 13, 1937. That describes a factory "fix" for chattering rear Big Twin brakes. Basically involves grinding the ends of the brake linings a little bit. I tried it, and it worked on my '37. Would at least be a stop-gap for you, until you find new(er) parts.
It's in the Antique Cycle Supply reprint of, "Shop Dopes, Volume Two."

It basically tells you to grind the top ends of your brake linings, after installation on the shoes, to 5/64ths-inch thickness for the first 5/8ths of an inch from the ends- that's the shoes' pivot stud ends. On the operating camshaft ends, grind both linings down to 5/64ths-inch thickness for 1 3/4-inches.
Says, "Apply this change to any brake that develops chattering and grabbing, also when servicing with new liners." Honest Injun!

[deluxe-styling]

Thanks for that Gerry.
Can't find a replacement rear brake drum in the UK or Europe at the moment. If anyone knows a good spares shop that could help I'd appreciate the tip.

[knuckleheadtim]

I'm a little mystified by the pictures of the brake operating lever. In the 1st picture the lever appears to be on correctly by the curvature, yet in the 3rd shot it looks to be offset away from the backing plate. Is it an optical illusion, or does the lever have the wrong bends in it? This can raise havoc with the operation because the lever can cock the actuator cam if the offset is facing out instead of in.