Topic: Rear wheel bearing help

[mic-57]

I have a 73 CB750 when I tried replacing my rear wheel bearings this weekend I could only find two, everything I've read says that there are three. The axle spacer goes from bearing to bearing and is snug. Could I have a different hub? Also I wanted to check the condition of the wheel dampers could anyone tell me how the drive flange comes off?
Thanks

[Steve F]

Not sure about the "K" model, but on the "F", there's the third bearing on the cush-drive assembly attached to the sprocket.  Once you get apart, you'll see it.  It (the cush drive) should just pull off.

[750duo]

mic-57

I also have a 1973 CB750

For the last few days I have been trying to replace the 3 rear wheel bearings. I have not had a great deal of success - but

From what those on the forum have been saying - the "cush" drive should just come apart- some have suggested by hand. This has not been my experience - no amount of gentle persuasion has moved it at all. Some beating on it has not caused any movement.            


The 1st bearing is located on the brake drum side with the spacer between it and bearing #2. They are both 6304 bearings and are in the hub itself. The third bearing is in the final drive flange (the part the sprocket is bolted to) and is a 6305 bearing.

The #3 bearing is in the final drive flange and is held in by a bearing retainer that has 4 holes for a spanner wrench and is probably staked in at least 4 places. You have to drill out the stakes (a small drill and probably not more than 1/4 or less depth) If you do not do this you will certainly strip out the aluminum threads. As it is, 33 years of no maintenance makes it quite stiff. Flood it with WD-40 or PB Blaster before you do it. I made up a tool from scrap I had around- 1" x 3" x 28" steel tube and tacked 2 pieces of 3/16 unthreaded rod to the 1" side. I got it out but was not easy - bent the rod somewhat but it did the job. Point is - Don't expect it to be easy. Then you are supposed to be able to drive it out after you remove the "cush drive".

#1 bearing on the brake drum side can be removed by forcing the spacer slightly sideways to reveal the edge of the bearing. You can then take a drift from the other side and pop it out. The spacer will just fall out of the hub revealing the full side of #2 bearing.

The preferred method of removing #2 bearing is, I'm told, by removing the final drive flange (cush drive) and then removing the #2 bearing retainer(screwed into the hub on top of the #2 bearing) and then driving out with a drift from the brake drum side. Since I have not been able to get the "cush drive" off, I have not been able to get either #2 or #3 bearing out.

If you can access my post "rear wheel bearing removal and rubber baby buggy bumpers" there is a diagram of the rear wheel from the Honda CB750 Shop Manual Fig. 13-14

I am very interested in any progress or lack thereof you may have

Keep me posted   Tom

[mic-57]

Well I definatly do not have a 750 wheel it is possibily from a 550. I was able to get the drive plate off by using a rod and driving it off from the brake drum side (mine has four access holes drilled behind the drive gear studs). The bearings were pretty straight forward once I made a tool to remove the retainer. Looks like I will be looking for a new rear wheel at my next tire change

[750duo]

mic-57

I got the final drive flange off tonight. I had previously tried to drive it off from the brake drum side but was afraid that I might damage the flange with the drift.

I got mine out by fastening the wheel to the floor and using an engine hoist to pull the drive flange  off the hub. I estimate that it must have taken about 150 lbs of (gentle) force to break it loose from the rubber dampers. 

I still have to remove the #2 bearing retainer and remove the #2 bearing but the other two are now history - boy were they worn out. Glad I decided to remove them.

Thanks, Tom