Rear Axle moves when I apply brake!

I have a 1976 kz900 ltd. Just got it. I took it for a spin today and every time I applied the rear brake, it felt like the back end was sliding out from under me. So I put it on my stand, started it up and put it in 1st, and appled the brake, When I did, the right side of the axle moves back approx 3/4". I haven't taken anything apart yet, because I wont know if anything is missing or not.( dont have diagram). I tried tightening the castle nut, but it just tightened up the wheel bearings and the wheel wont spin. I also tightened the chain tightener. the tightener seems to keep the shaft from moving ahead, but the shaft moves back when i I apply the brake. So does anyone have suggestions or clues as to what the problem could be?

pauleaston wrote: ... tried tightening the castle nut, but it just tightened up the wheel bearings and the wheel wont spin....

Likely that wheel was incorrectly fitted into the swing arm.

See link in my signature for kawasaki.com which includes a parts diagram for the rear wheel.

Goof Fortune!

are all the pieces there?






sorry for the dirt, these were before pictures

Do not ride it at all until you correct the problem. You are either missing pieces or pieces are installed wrong. Ed

.

pauleaston wrote: I tried tightening the castle nut, but it just tightened up the wheel bearings and the wheel wont spin.

If assembled correctly that should not be physically possible - something is definitely assembled wrong or missing.

Here's a diagram of your rear hub assembly, what you should pay special attention to are the spacers (the parts I marked in red): #3, #12, #20, #25 and #26. Obviously also check the condition of the bearings.

#3 goes between the left side adjuster and the sprocket hub (outside of bearing #11).

#12 goes between the sprocket hub and the wheel (inside of bearing #11 and outside of left bearing #17).

#20 sits inside the hub between left and right bearings #17.

#25 goes between the right bearing #17 and the caliper bracket.

#26 goes between the caliper bracket and the right side adjuster.

Check that all spacers are present and have the correct thickness - they should only touch the inner bearing races, even with the castle nut tightened to the max the wheel should spin freely, provided the bearings are good.

Btw, just a thought, also make sure that the binding isn't the caliper mount moving in when tightening, locking up the rear brake.

Hope this helps you some, a stuck rear wheel at any speed is no fun.

The good part is all those red numbered part's are no longer
available.

I'm doing a 78 KZ1000 disk wheel in an 83 Gpz swingarm and the wheel
I got has missing spacer's so I looked yesterday and Kaw.
say's no go.

.

If you find out you are missing parts, post which numbers in OnkelB's diagram you need and folks on this site can help you find them. Ed

See if part #20 is there the axle spacer that goes inside the wheel between the bearings. I think you could possably be missing a bearing or it came out without the inner spacer. In any case park it & fix it before it dumps you on your rear. If you tell me whats missing I may have it, Ill sure take a look for you.

#12 and #20 are the spacer's that locate
the #17 bearing as it's a floating bearing.

With out #12 or #20 when you tighten the axle
and bottom the bearing you then start to pull the inner race
in till the bearing's trash.

Any one have a #3 for a disk brake spoke KZ wheel?
I like to find a complete wheel.

Bob's Used Motorcycle Parts

Give Bob's a call. I know for a fact they have exactly what you are looking for. Nice thing about AZ, old stuff just gets old, no rust or rot.