Gear change shaft not catching any gears???

[Bladerunner]

Hey Fellas,

I just finished installing a new set of sprockets (both) and drive chain. All was going well until I went to replace the sprocket cover on my '78 GS750 only with a mild amount of horror noticed that the input shaft that your left foot uses to change gears up/down now rotates about 45 degrees counter-clockwise and will not catch a single gear. WTF........??

The countershaft/front sprocket spins freely as the bike was in nuetral while installing the new chain/sprockets, and the (gearchange) shaft now moves in and out about 3/8 - 1/2 inch if pulled or pushed?

Is this unfixable? I have no idea what I did wrong or how to make the bike shift again? HELP......

Thanks,

Trent

[SqDancerLynn1]

Just a guess. Since there is a lot of play ? The C clip is probably missing from the shifter shaft and the shifting ratchet popped out of place. SO it may require a clutch removal

[Nessism]

Just a guess. Since there is a lot of play ? The C clip is probably missing from the shifter shaft and the shifting ratchet popped out of place. SO it may require a clutch removal

Sound like a good guess on Lynn's part. You will have to remove the clutch cover on the other side of the engine, and pull off the clutch hub in order to put the shift shaft properly in place. Sounds more difficult than it is, although you will need to get your hands on a tool to get the clutch hub nut off.

Good luck

[Bladerunner]

Thanks for the help guys. I already have the clutch cover off as its being polished by another forum member. I have access to the hub holder and impact gun required to take the clutch out. I'll be working on it this afternoon to see if I can fix this problem. Damn, and all just to change the sprockets..........!

Anyone care to volunteer a phone number for some advice if I get stuck on one part of the procedure?


Trent
641.344.9254

[tkent02]

It's a good idea to pull the clutch anyway to inspect the basket, springs, rivets, etc. Easy stuff to do.

[Ross]

Yea until you go to your 3/4 inch drive set assuming you will have a socket big enough...................nope not in my set.. I think it is 80mm on my oil cooled.

[koolaid_kid]

80mm ~= 3.15"
Wow, that is huge!

[Bladerunner]

Yea until you go to your 3/4 inch drive set assuming you will have a socket big enough...................nope not in my set.. I think it is 80mm on my oil cooled.

Nope,...the nut holding the clutch basket to the output shaft is ONLY 32mm. And I had one of those in my "Ducati" toolbox.

I was finally able to tear into the bike today, and the problem has been fixed. The problem was the gear drive on the end of the gearshift rod that extends through the motor to engage the transmission. It had slipped out of place while the clutch cover was off, which holds it in proper position. The splined input to the transmission had also been engaged (in gear) which would not let the shift-shaft (also meshed) re-engage.

Once the clutch basket was removed, I could get everything lined back up and re-engaged. Everything is now buttoned back up and working perfectly.

When removing the clutch basket, it was easy to get the 32mm nut off the input shaft by placing a 2"x4" between the spokes of the rear wheel and the bottom/top of th swingarm for removal and re-tightening. The drive chain off the rear wheel kept the input shaft stationary so the nut holding the clutch basket assembly could easily be removed and retightened. The SERVICE MANUAL was invaluable!!

[gearhead13]

There is normally a clip on the shifter side that keeps the shaft from sliding too far in with the shifter removed. At least the ones I have seen have the clip.
# 30 for the washer and 31 for the clip in the pic