Topic: 73 CB750 Rear Hub Help

[754]

Try to lay hub on ground, and hold with your bootsoles inside the spoke flanges, the pull up on reattached sprocket. Failing that use two 1x4s against the flanges and screw down to piece of plywood.
 The sprocket likely is aluminum, and was harder To get off if it was corroded on the interface, between it and the hub.

[Powderman]

I knocked the nipples off the backs of the rubbers and was able to hammer the drive hub out. Now I am still having trouble breaking the bearing retainer loose on both hubs. They weren't meant to come out were they. They should thread the four holes so you can thread some bolts in to get leverage with a bar.

[MCRider]

I knocked the nipples off the backs of the rubbers and was able to hammer the drive hub out. Now I am still having trouble breaking the bearing retainer loose on both hubs. They weren't meant to come out were they. They should thread the four holes so you can thread some bolts in to get leverage with a bar.

Referring back to my post #10. They definitely will come out fairly easily IF you drill out the locking stakes first. The stakes were done by the factory, essentially punch marks at the line where the internal and external threads meet. By deforming the first several threads with the factory punch, the retainer is locked from turning. If you drill them out with a bit sligtly larger dia than the stake, adn drill slightly deeper that the stake, like an 1/8" deep. Then the retainer will break loose with a slight effort and turn.
IF you  need guidance on a pin spaner DIY or otherwise let us know. This bridge has been crossed many times on the forum. In the worst case, where the stakes are not drilled, severe damage can be done to the hub. With drilling, the retainers come out and can often be reused.

[Powderman]

I knocked the nipples off the backs of the rubbers and was able to hammer the drive hub out. Now I am still having trouble breaking the bearing retainer loose on both hubs. They weren't meant to come out were they. They should thread the four holes so you can thread some bolts in to get leverage with a bar.

Referring back to my post #10. They definitely will come out fairly easily IF you drill out the locking stakes first. The stakes were done by the factory, essentially punch marks at the line where the internal and external threads meet. By deforming the first several threads with the factory punch, the retainer is locked from turning. If you drill them out with a bit sligtly larger dia than the stake, adn drill slightly deeper that the stake, like an 1/8" deep. Then the retainer will break loose with a slight effort and turn.
IF you  need guidance on a pin spaner DIY or otherwise let us know. This bridge has been crossed many times on the forum. In the worst case, where the stakes are not drilled, severe damage can be done to the hub. With drilling, the retainers come out and can often be reused.

The stakes have all been drilled and the hub heated with a torch to ease disassembly. All of this would be easier if the hub were not disassemble so there 's no real way to hold everything tight while working on it. I've been using a drift and hammer but it is causing more deformation of the holes than I prefer.
I was considering making my own spanner. Any threads you can direct me to on the subject?

[chewbacca5000]

Can you mount it to a piece of plywood or something?  Maybe a few drywall screws through the spoke holes will stop the hub from spinning.  You may need to drill a little deeper.

I used a star screw driver as a drift and for some reason that worked.  Key is to get the stakes out.

He may need to replace the retainer any how.

[Airborne 82nd]

http://forums.sohc4.net/index.php?topic=132409.msg1479566#msg1479566

http://forums.sohc4.net/index.php?topic=132409.msg1479566#msg1479566

From  MCRider May 18, 2009
Then, my last tool I made was a flat piece of strap aluminum, about 24 inches long. Drill two holes in it the space of the notches in your retainer. Put two small short bolts in each hole with nuts to hold them there. THis tool should easily turn the retainer. Here's mine about a third of the way down page 29: http://forums.sohc4.net/index.php?topic=36459.420

Mine requires no welding or tools other than a drill. Not my idea, stole it from someone here.

[MCRider]

Thanks AB.

Pwdrman: Granted, the bare hub would be harder to work with.

[Powderman]

Chewy, I may not have gone deep enough on the drilling of the stakes. Gonna get back at in awhile.
AB, I have pictured in my mind exactly what you describe.

[754]

As a machinist,  i have not drilled the stakes deep enough, I was embarrassed

[Airborne 82nd]

Thanks AB.

Pwdrman: Granted, the bare hub would be harder to work with.

No sir Thank you I made that tool like you describe and it worked perfect. If I ever need it again I might cut some slots to use it on other jobs.

Powderman if you want to spend money look at this
https://www.davidsilverspares.com/CB750K-FOUR-1978-USA/part_236408/
I don't care for tools that can only do one thing and I only need it every couple of years.
MC has the best bang for the buck.

[Powderman]

Alright, I drilled a bit deeper and was able to get all retainers and bearings removed. I will suggest to the customer that the retainers be replaced as well as all he wheel bearings and seals. Are the retainers usually replaced? I know at least one of these (the cush hub retainer) is in good enough shape to reuse and the others may be as well. I'm being to see first hand how expensive a CB750 restoration can be if done correctly.

[chewbacca5000]

Bearings need to be replaced.  Retainers can be reused if not too messed up.  They are only $20 bucks or so.

[Powderman]

I assume this bike has sat for a number of years. When I pulled the brake backing plate off the shoe pads fell on the floor,not uncommon as I understand.

[MCRider]

Thanks AB.

Pwdrman: Granted, the bare hub would be harder to work with.

No sir Thank you I made that tool like you describe and it worked perfect. If I ever need it again I might cut some slots to use it on other jobs.

Powderman if you want to spend money look at this
https://www.davidsilverspares.com/CB750K-FOUR-1978-USA/part_236408/
I don't care for tools that can only do one thing and I only need it every couple of years.
MC has the best bang for the buck.

   

[Powderman]

After drilling the stakes deeper I was able to get everything apart.

[MCRider]

After drilling the stakes deeper I was able to get everything apart.

Yay!

[chewbacca5000]

After drilling the stakes deeper I was able to get everything apart.

Does this mean you are now offering this as a service? If so got some I will send your way.