Topic: CB750 K0 shift drum doesn't seat

[jebon]

I tried with the upper case on to fix the upper shaft at the bearings. Still very unstable shifting. I took it apart again to try and show you what I'm seeing. I took a drill on the upper shaft on the clutch side and started shifting. I don't know if you can make anything of this and I'm sorry it's painful to watch. The scraping noise at 1.07 is just two of the cogs rubbing slightly because the upper shaft is not fixed at the bearings. It behaved completely the same with the shaft fixed by the upper case.

Video:

I saw that two holes in cogs in the lower shaft were not aligned but aligning them did not make any difference. I just want to say that before I took it apart there were no gear issues like this so I'm guessing either I've done something wrong or it will fix itself when there's load on the transmission. I hope to be able to find a bug though

[jebon]

I can't seem to find anything wrong or any documentation on if the holes should be in line on the lower shaft.
I'm guessing when there's load on the shafts and the final drive and continuous pressure on the lever the dogs will find their way easier.
So unless someone has some light to shine on this I'll proceed and button up.
Thanks for your comments 

[69cb750]

I can't seem to find anything wrong or any documentation on if the holes should be in line on the lower shaft.
I'm guessing when there's load on the shafts and the final drive and continuous pressure on the lever the dogs will find their way easier.
So unless someone has some light to shine on this I'll proceed and button up.

When the bike is rolling down the road the engine is spinning the clutch and the shaft even with clutch released.
The rear wheel is spinning the other shaft.
So both shafts are spinning and the dogs fly by the holes.
When you press the shift lever the dogs enter the holes and you are in gear.
You can test all of this on the bench, the goal is to shift through all the gears.

[jebon]

I can't seem to find anything wrong or any documentation on if the holes should be in line on the lower shaft.
I'm guessing when there's load on the shafts and the final drive and continuous pressure on the lever the dogs will find their way easier.
So unless someone has some light to shine on this I'll proceed and button up.

When the bike is rolling down the road the engine is spinning the clutch and the shaft even with clutch released.
The rear wheel is spinning the other shaft.
So both shafts are spinning and the dogs fly by the holes.
When you press the shift lever the dogs enter the holes and you are in gear.
You can test all of this on the bench, the goal is to shift through all the gears.

Thanks. I'll just double check that the big inner cog is flipped right and that's it then.
Thanks for all your comments

[HondaMan]

Yeah, now that I think back (WAY back, like 2006 or so) on it: I once assembled one of these from several boxes and put the inner gear on the countershaft on backward (it turns the oil pump). I only discovered my error when I had the case lying on its side and turned the crank to check shifting (no pistons in yet) and heard a scraping sound. The gear that operates the pump off that one gear biased the gear sideways just enough to make noise against the one next to it. I remember being happy that I had not yet assembled it into the frame...I forgot about that episode, sort of like one forggets about a snakebite. At least it wasn't a poisonous snake (black snake).