Topic: Washers for rear disk brake bracket and axle?

[crp_iii]

How many washers should there be on the rear axle?  I have a 77 CB750F that is screwed up.  The axle was not aligned and the rear brake was rubbing and caught fire on my way home.  I am waiting for the Clymers and Hayes manuals I ordered to arrive so I do not have a diagram.

The bracket  is rubbing by the green arrow. It generated enough heat when I was trailering for the disk to be glowing red and light the rubber dust boot on the bracket on fire.  I am pretty certain there should be a washer by the castle (nut red arrow).  Should there also be one by the blue arrow?

If there isn't supposed to be a spacer there how can I straighten out the bracket so it won't rub?

Thanks in advance,
Chuck

[OldSchool_IsCool]

CRP,

Check out the fiche links on this thread for diagrams and part numbers:

http://www.sohc4.us/forums/index.php?topic=12339.0

[750goes]

Not a related question,
BUT
are there any brake pads in the rear caliper ?

If it was smoking on the way home, it could well be seized pistons in the caliper....

good photo too

[scondon]

How many washers should there be on the rear axle?  I have a 77 CB750F that is screwed up.  The axle was not aligned and the rear brake was rubbing and caught fire on my way home.  I am waiting for the Clymers and Hayes manuals I ordered to arrive so I do not have a diagram.

The bracket  is rubbing by the green arrow. It generated enough heat when I was trailering for the disk to be glowing red and light the rubber dust boot on the bracket on fire.  I am pretty certain there should be a washer by the castle (nut red arrow).  Should there also be one by the blue arrow?

If there isn't supposed to be a spacer there how can I straighten out the bracket so it won't rub?

Thanks in advance,
Chuck

   There aren't any washers on the axle/brake assembly. The only "spacers" are the two that insert into the wheel hub, one on each side. I've taken a couple pics of the spacer that fits on the brake arm side.

[crp_iii]

The pads and caliper were on and the wheel spun ok, but it was rubbing.  The friction made the metal expand more heat more expansion more rubbing poof a nice flame it was buring when a guy honked and yelled YOUR BIKE IS ON FIRE !!  The piston seal and dust boot covers caught fire and melted. I am happy the break fluid did not ignite.  

I have a rack that plugs into my trailer hitch.  I had the front wheel secured in the rack and was trailing the rear wheel.  When the guy said it was on fire I thought the wheel blew and there were sparks.  I didn't make sense to me, aluminum rim and all.  The tire looked good and had air.  So I pull into a lot and hop out and see a nice flame and melting plastic.  I took the caliper off to finish towing it home. The disk was warm but not glowing red like it was with the caliper on.

Now I am just trying to straighten things out. I am sending out the calipers to get the sheared off screws removed and Speed bleeders installed.  I am going to try and pull the carbs and clean them.  Then I will try and get the parts to rebuild the breaks. If I get the motor running I have to be able to stop because a cruise around the block is mandatory.
 

[crp_iii]

Hmmmmmm.

Thanks SCONDON, the spacer is there.  I bought a couple different sized washers to try and space things right figuring there should at least be one under the axle castle nut.

[scondon]

There hasn't been a washer on any of the three 77-78 750F's I've had, but that doesn't mean anything since they were all previously owned.

   If the rear wheel isn't mounted straight (same # of alignment marks on each side) then you can end up with a disk that rubs. The marks would have to be off by quite a bit but if the rear wheel wasn't tightened down well or the chain tension adjusters were slacked off then I could see this causing a problem while towing.

   

[crp_iii]

The axle was off several ticks on the spacer marks.  It is straight now with correct tension on the chain but the backet is not centered on the disk.  With the axle loose I pushed the bracket  a few times with a hammer handle from the other side thru the wheel.  It is not rubbing now but the gap is like a 1/4 inch on the wheel side and a sheet of paper thick on the caliper side.

[Gabus]

I just looked at my F2..there are no washers. I have approximately .090 at the top of the disk/mounting bracket on the caliper side and .070 on the wheel side.