Rear caliper bracket rubbing

[tommystinson]

My caliper bracket is rubbing against the rear rotor on my '79 SF. It appears to have been going on a little while, as you can see slight wear in the bracket. I have had it apart the past week, replacing tires and wheel bearings, etc. I thought it was the pads dragging before I took it apart, but neglected to investigate further during the tear-down. I've been through my service manual 10 times looking for a washer or spacer I may have missed during re-assembly, but I don't think that is the case. It looks like I would need 2 mm or so on the axle to center the rotor on the bracket slot. If the slide on the caliper seized at some point, could that have bent the bracket just enough to make it rub? I put a .030 shim in the axle assy next to the metal dust seal, and it keeps it from rubbing. It still isn't centered, though. Any ideas?

[tommystinson]

Another thought- It certainly feels like the splines are engaged well between the wheel and the drive unit, but is there a dimension I can check, like between the plastic guard and the drive unit itself?

[tommystinson]

Okay, I guess this thread just isn't that interesting, but please, please, PLEASE... I need help. Could someone send me a digital pic of their plastic gear shield on their rear wheel where it meets the final drive? I really need to rule out the gears not "meshing" completely before I stick a washer on the axle to center the caliper bracket. If someone would consider a phone conversation, shoot me an e-mail and I'll give you my number, or I'll call you. Thanks!!!

[randy]

Tommy, if you've got the axle nut torqued down to 107 ft/lbs, then don't worry about the splines not meshing. Take a look at the axle seal just behind the brake bracket. There should be a metal collar that extends about 1/2" into the wheel. I'll bet that it's missing or misplaced on the axle.

HTH

randy

[tommystinson]

Randy, thanks for the reply! I think I've got it right, I'm working out of the Haynes manual. Does the piece you are referring to have 2 diameters, with one of them going into the oil seal, and the other one having a thin metal dust cover on it? If so, I should be good in that regard. It's hard, the guy that owned the bike before me was a total hack. An example: He apparently lost one of the acorn nuts holding the cover on the rear master cylinder. So he then forced on a 10-32 nut with a lockwasher. I don't mind improvising, but that type of stuff makes me ill. I want to do this right, but it's a lot easier if it was put together the right way to begin with!

[Geezer]

That sounds like the right spacer. I've seen caliper brackets bend when the caliper slider pins are seized. This effectively gives braking only one side and the bracket was never meant to take that kind of side loading.

It's possible that some time your bike had this problem and the caliper was repaired or replaced but the bracket was not.

I'm not sure how you would go about straightening the bracket but I'd certainly make sure the caliper has smooth side ways motion on the pins. If it's stiff or seized, take it apart, clean and lube it. You'll still have to deal with the bent bracket but a soft faced hammer might fix it but do get over zelous when pounding on it.

Geezer