1980 GS450E - Empty spot between 5th and 6th

[Lee]

Hello everyone,

I am brand new here and created this account after not finding anything about what I am having an issue with. My transmission will hit a spot between 5th and 6th that acts basically like neutral(no power). I have torn the entire bike apart as a project and to correct this, however now that I am looking at the transmission I can't see any obvious signs of bent forks or anything that might cause this issue.

Any ideas or methods for checking in more detail to ensure nothing is bent? Or ideas as to what else might cause this issue?

I don't have any real experience in mechanical repairs, just the basic change my own oil level of experience.

Thanks,

Lee

[pete]

Hey Lee, welcome! Good choice in bikes...

Believe it or not I rebuilt my motor for almost exactly the same reason... but mine was slightly different. When I changed from 5th to 6th if I didn't really kick it hard into gear and accelerated, it would drop back to 5th.

Turns out there is no issue with my gearbox, but the heim joints on the gear shift linkage were flogged out from years of use and in addition the lever pivot is also flogged out, meaning too much slop in the change lever setup.

I replaced the heim joints with ones from a hobby shop and it was an immediate improvement.

I haven't done anything with the pivot yet but eventually I will get a new pivot bolt (available from Suzuki) and if that doesn't solve the issue I will also drill the pivot on the lever out and sleeve it down to the correct diameter.

That should sort it all out...

[Mekanix]

The forks or the gears could be worn just enough to not allow them to catch.

Like pete says, If you don't get enough positive force on the lever you won't get the transmission to want to get to the next gear.

You could turn the shift drum by hand and get to that spot between 5 and six and then look at the gears that are supposed to go together. Either the gears are worn or the end of the shift forks are worn, or even the two of them are worn together, It could be the shift drum is worn in that spot.

On the right side of the case there is an idler wheel that helps to center the drum in each gear, There is a spring that pulls the wheel between the notches on the gear of the shift drum. Most of the time when you shift into a gear and don't quite get all the way into the gear, this wheel helps the drum keep rotating until its all the way in gear.

In between 5 and 6 you could be balancing the wheel on the tip of the star and it doesn't know which way to go.

I've tried replacing the spring with another one and that does make it a bit harder to shift but it will definitely be more willing to go into gear. It will either not go to the next gear and fall back to the previous one or if you get over the tip it will force itself into the next gear.