Brake camshaft shim and wave washer???

[Royboy]

Most of my bikes have disc brakes front and rear. I should have looked more carefully when I disassembled the rear drum on my restomod project 77D. Below the actuating cam there is a part called the camshaft shim. Neither my Haynes or Clymer manual shows how the shim should be oriented on the shaft. The underside of the shim has obviously been machined to accomplish a task I haven't been able to determine

Secondly, Haynes shows a wave washer between the shim and the brake plate, Clymer does not. There was no washer there when I disassembled it. Should one be there?

Any advice will be appreciated, good advice will really be appreciated.

roy

 

[5twins]

I don't ever recall seeing a wave washer on any I took apart. That shim/washer you have is a throw back from earlier models that had a brake shoe wear indicator. It was eliminated by your model but the casting is still evident on the brake plate .....

On earlier models, the casting had a threaded hole through it and a plunger type switch screwed in. That machined ramp on one side of your spacer washer would activate it if the shoes wore too much allowing the cam to rotate too much.

 

[Royboy]

Thanks 5T, I needed that!

roy

 

[5twins]

I should add that even though you no longer have that brake wear switch, you still need to keep the shim/washer. It spaces the brake shaft/cam out correctly to contact and work the brake shoes.

 

[ryamatt]

Is there any info on the orientation of that camshaft shim? I am in the same situation with a disassembled drum brake.

 

[Royboy]

I think what 5 twins is telling us is that unless your bike has the wear indicator the orientation of the shim doesn't matter, it just needs to be in there. If your bike does have the wear indicator the orientation should be apparent (I think).

roy

 

[5twins]

The washer only fits on correctly one way. In Roy's 1st pic, you can see that side of the washer is cut out to fit onto the cam.

 

[dirtyfuerty]

I'm having same problem now any updates on the cam wave washer inclusion or exclusion

 

[650Skull]

Have my doubts about these new 1st poster guys who drag up a 7 year old thread and ask a question when the thread has the answer not once but twice.........mmmmm..........kinda feels a something 77 or 77 something ring to it......

 

[5twins]

I just took another '77 brake plate apart today for renovation and again, no thin wave washer, just the thick beveled spacer washer like in Roy's pic above. That wave washer is only shown in the '74-'79 diagrams but as I said, I've never run across one. Makes me think the diagram could be a mistake.

In 1980, Yamaha did away with that funky beveled washer and just stuck 2 plain washers in it's place. Obviously cheaper than making that special washer whose beveled notch was no longer needed anyway.