From 6th gear to 5th

[stu78]

Hey guys and gals,

I was out for a ride last night and as I was entering the freeway on the "on ramp", I accelerated fairly hard and the gearbox popped out of 6th and into 5th all by itself.

It was interesting because I just picked up a little speed in 5th and put it back into 6th and didn't have a problem for the rest of the night. As I was on the "on ramp", in 6th gear, I would guess I was doing about 80 or 90 km/h and running at about 6,000 rpm. I basically opened the throttle wide and it slowly picked up for a bit then just went down a gear. I assume that I didn't click the shifter hard enough up into 6th when this happened. Maybe the gear barrel wasn't seated enough to stay in there. Is it by design, if the bike's gearbox pops out, it finds its way into the next closest gear?

Like I mentioned, no harm done. The bike rode very well for the rest of my ride.

[stu78]

Sorry....please move this to the 2 Cylinder Engine/Drivetrain/Clutch forum. Thanks.


Alex

[Steve]

Sorry, can't help you with your problem, but YOU are the one that can move the thread.
Actually, you can copy the text in your first post, then delete the first post, the whole thread will disappear.
Then put it in the forum you want.

.

[stu78]

Thanks for the help on moving the thread. You helped with one of the issues.

[Guest]

There are two types of engagement systems in these gearboxes. One I refer to as 'pin in hole' and the other is dog to dog. Sixth is pin in hole where some prongs slide into holes on the gear to be engaged. Unlike dogs which can be under cut to draw the gears into engagement, the pins can hang up partially engaged and spit themselves out later. Suzuki tried to keep gear lash to a minimum in sixth so the pins are large and the holes are somewhat tight.

There's a spring loaded roller gizmo on the shift drum that in theory completes the engagement, but it doesn't always work every time. The fix is to keep pressure on the shift lever until the gears are in and loaded with the clutch out, if you are using it. Otherwise it can pop out and the spring gizmo flips it back into 5th. Once you realize that it isn't the same as the other five, you can just accept that 'overdrive' take a bit more care and attention. At least you get a sixth….

I got a bike from an 80 plus guy who must have either never gone that fast or never knew there was more than five. Sixth was seriously hard to engage for a long time. Using synthetic oil helps a lot on this particular gearbox, and if you are using the usual Rotella type diesel oil it may be a sign that you need to freshen up.

[sam000lee]

That's happened to me a few times on my GS450. I'll upshift to 6, and about 10 seconds later it will drop out of gear into a false neutral (causing revs to shoot up) or drop immediately into 5th. It's happened maybe 4 times in the past 3 years seemingly randomly... I never thought too much about it and it hasn't become a frequent occurrence so haven't worried.
The first time it was a little nerve racking since I was going 70mph up hill on the highway and I thought my engine was blowing up haha.

[kerrfunk]

I've found a neutral between 3rd and 4th occasionally...

[stu78]

There are two types of engagement systems in these gearboxes. One I refer to as 'pin in hole' and the other is dog to dog. Sixth is pin in hole where some prongs slide into holes on the gear to be engaged. Unlike dogs which can be under cut to draw the gears into engagement, the pins can hang up partially engaged and spit themselves out later. Suzuki tried to keep gear lash to a minimum in sixth so the pins are large and the holes are somewhat tight.

There's a spring loaded roller gizmo on the shift drum that in theory completes the engagement, but it doesn't always work every time. The fix is to keep pressure on the shift lever until the gears are in and loaded with the clutch out, if you are using it. Otherwise it can pop out and the spring gizmo flips it back into 5th. Once you realize that it isn't the same as the other five, you can just accept that 'overdrive' take a bit more care and attention. At least you get a sixth….

I got a bike from an 80 plus guy who must have either never gone that fast or never knew there was more than five. Sixth was seriously hard to engage for a long time. Using synthetic oil helps a lot on this particular gearbox, and if you are using the usual Rotella type diesel oil it may be a sign that you need to freshen up.

Excellent explanation. Now that I can visualize it...it makes way more sense.

[stu78]

That's happened to me a few times on my GS450. I'll upshift to 6, and about 10 seconds later it will drop out of gear into a false neutral (causing revs to shoot up) or drop immediately into 5th. It's happened maybe 4 times in the past 3 years seemingly randomly... I never thought too much about it and it hasn't become a frequent occurrence so haven't worried.
The first time it was a little nerve racking since I was going 70mph up hill on the highway and I thought my engine was blowing up haha.

It happened again this weekend on a 3 hour trip. I looked down and realize that my toe of my shoe was resting on the gear shifter without me realizing it. I think I may be bumping the gear back down with the weight of my boot. I don't know for sure but after moving my foot back so the ball of my foot rests on the peg, it didn't happen again.