Topic: 75 CB550 gear selector drum stuck?

[Emagbnim]

How you guys doing? First some history of the bike.  I bought a 75 CB550 about a year ago.  The previous owner was in the process of restoring/cafe racerizing it.  So it was wasn't running but did turn over with the kick starter ok.  It was in neutral and rolled freely.  Also there was very little oil inside.  So far I've gotten the engine to run after going through the carbs and top end.  I am at the point where I was checking if the clutch and transmission are ok and found that it won't go into any gear.  I opened the clutch cover and removed the clutch basket to take a look at the levers.  It looks like the main lever is grabbing the selector drum and rotating it a little but not enough to go into gear.  It just starts to push the neutral index lever away but not enough to get out of the notch.  I can manually pull the neutral lever away and the drum still won't move further.  Now this bike definitely sat for awhile.  I don't know exactly how long but carb 1 and 2(which is the side that sits low on the stand) were quite rusted inside and the clutch plates had some rust on them.  I think most likely something could be rust welded or gummed up or at least thats what I hope.  I don't want to push on the drum too much as I know I could bend the selector forks or something.  Any ideas of what else I could check or do?  I've been drenching the whole area in WD-40.  I've worked a lot on older cars but never done anything to a transmission beyond changing fluids and replacing clutches so I am very unsure of what to do.  I've been considering trying to find a shop that could take a look at it since I know these kinds of things can be difficult to solve over the internet but figured I should at least give it a try.  I feel like I've come pretty far on my own so I don't want to quit now.     

Thanks,
Alex

[Kevnz]

Have you tried turning the gearbox input shaft as you go? Possibly just a case of gears not lining up; also tried changing up into 2nd as well? Or spinning the rear wheel?

[Emagbnim]

The input shaft is the one the clutch was on right? I have tried spinning that while trying to spin the drum either way.  I did notice a stick point on that shaft where it seems to resist a little but it does spin past it.  I haven't tried spinning the rear wheel though.  I can try that tomorrow.

[Emagbnim]

I made some progress and now have 2nd and 3rd.  I decided that if I have to open the transmission to fix this then what does it matter if I break something forcing the drum.  So very slowly I applied force to the nut on the drum in the tightening direction and it just went in.  I tried applying about the same force to get into 1st and 4th but no go so I'm gonna keep soaking it and working it  through the gears.  I ordered new clutch plates and springs so when they come I can put the clutch back together and get some oil back in there which will maybe help.  I've seen in an exploded diagram of the transmission that there are 3 selector forks so I'm assuming that maybe 2nd and 3rd are on one 4th and 5th are on another and 1st is on the last.  So maybe I just broke loose one.

[dave500]

if the shafts aint spinning its hard to just select gears,if you rock it back n forth it should.

[Emagbnim]

Yeah I figured out thats what the little resistance was when I was sometimes spinning the shaft.  It was almost in gear just had to play with it a little and hit the selector again.  It goes into 2nd and 3rd easy now but 1st ,4th and 5th are still not engaging so I think they are still stuck.

[bryanj]

I doubt it, both shafts need to be turning for most gears

[Emagbnim]

I'm able to get it in gear by just playing with the shaft the clutch sits on.  I was sayin sometimes I'd hit the selector and get some movement on the drum but not enough to get in gear. If I spun the shaft then I'd feel some resistance at some points like the gears weren't lined up like you guys are saying. If I just spin the shaft some and hit the selector again it goes in.  They were definitely stuck though. It took soaking the selector forks through the little window to the left of the drum. Then turn the drum with a wrench while spinning the shaft.  Once they were broken free I could select that set with no problem.  So once I had broken 2nd loose I also got 3rd without having to break it free. Once I had 4th I also got 5th. 1st was the only one by itself and also the toughest to do because its direction on the drum is also the loosing direction for the nut on the drum. 

I do have all the gears now and got the clutch and clutch cover back together.  I haven't put oil back in to run it and test it but I did put it in first then rolled it forward with the clutch depressed and it seemed to be working. Let me tell you though getting the right information for the clutch plates and tighten torque for the four spring bolts drove me nuts. This engine has the clutch basket with a larger outer friction plate. The book I have for the bike said to put the smallest one on last and the kit I got didn't have a larger or smaller friction plate just seven identical friction plates and six metal plates.  I wound up just using the old larger one as it still had a lot of life it just had a little rust on it which I figure will just wear off. Then there was the four bolts that hold the spring plate. My book just says "tighten them fully" with nothing for them in the tightening torque section.  Then I found a video on youtube where this guy says "the tightening torque is 9 pounds but a lot of people break the bolts going to 9 pounds so just tighten them enough" ahhhhh well what's "enough"? I just tightened them down till it felt like it was pressed up against the clutch on all four then just a quarter or so more.