how does the clutch work?

[david]

i've got a 81 GS1000G that the clutch is not doing a thing. I took the cover off and haven't quite figured out how the thing should work and move inside.

I do have the Clymer, and it shows the parts, but not how they move and what they do. Does anyone know of any literature that might explain it, so that i can identify my problem? thanks

[rkubik]

clutch operation

1. The big disc in the middle (pressure plate) presses all the plates together. It has to move outward to disengage the clutch - springs resist the movement.
2. The vertical shaft to which the clutch cable is attached has a gear on the bottom. That gear engages with teeth on a horizontal shaft which goes into the middle of the pressure plate.
3. The horizontal shaft has a flange on its end which bears against the inside of the pressure plate via a bearing.
4. As the vertical shaft rotates, it should pull the horizontal shaft outward, which also pulls the pressure plate outward, letting the clutch disengage.

Things to check:
Is your clutch cable free play adjusted as per the manual?
Is the vertical shaft rotating when you pull the clutch lever?
Is rotation of the vertical shaft making the horizontal shaft move?
Is the pressure plate moving out and in as the horizontal shaft moves?

[Jethro]

I'll try to do the trick for you. Boy, I sure hope the G models have a similar clutch as the E's...

The clutch is basically a component that connects and disconnects the crankshaft to/from the transmission jackshaft. Basically there is a large drum called the "basket" that is fixed to the crank via a large helical cut gear. This is the very outside of the clutch, and always moves at the same rate as the crankshaft. Whatever the engine rpms are, the clutch basket has the same rpms. The basket has a large bearing that surrounds the tranmission jackshaft. The only thing the basket is permenantly attached to is the crank.

The next component to discuss is the clutch hub. The clutch hub is the inner portion of the clutch, and is permanently attached to the tranmission jackshaft. It fits nicely inside the basket.

Now the basket has teeth on the inside surface of it, and the hub has teeth on the outside surface of it. Think of the basket and hub as gears of a sort.

The next component to discuss is the clutch pack. This is basically two kinds of flat plates, one that is made of steel and grips to the teeth on the outside surface of the clutch hub called a driven plate, one that is made with a grippy surface called a friction plate that grips to the teeth on the inside surface of the basket. My bike has 11 driven plates and 10 fiber plates. These plates can float laterally on the teeth of either the hub or the basket.

The final part of the picture is the pressure plate. The pressure plate is attached to the hub with 5 springs in the middle. It has a pushrod gear in the center of it that is basically attached to the clutch cable and obviously the clutch lever on the bar. At rest, the springs pull the pressure plate firm and hold the entire clutch pack tightly together, basically joining the inner hub to the outer basket. In this position the crank is basically fixed to the transmission jackshaft. When you pull on the clutch lever, you fight the springs in the center of the clutch hub, pulling the pressure plate away from the clutch pack. This reduces friction between the two type of plates and allows the hub and basket to move independantly of each other.

That's it in a nutshell. Hope this helps you understand how it works a little better.

[david]

This is all exactly the info i was needing! thanks!

So, when putting the 6 big springs back in,,, should i screw the bolts holding them in, in all the way and make them tight? Or would they be backed out a bit to allow less tension on the springs?

[Jethro]

This is all exactly the info i was needing! thanks!

So, when putting the 6 big springs back in,,, should i screw the bolts holding them in, in all the way and make them tight? Or would they be backed out a bit to allow less tension on the springs?

That's right, 6 springs. Yes, tighten them secure. They shouldn't have any slack.

[SqDancerLynn1]

THEY SHOULD ONLY be torqued to about 8-10 ft lbs. DOn't overtighten or they will break. CHeck them for any thread streatch

[david]

good info for me. thanks guys.
i'm still trying to figure out why pulling the clutch on the handle bar wasn't doing a thing... could it have been as simple as adjustment on the cable?
i'd like to have an idea before i put it all back together.

a little info...
*pulling the clutch handle did nothing for releasing the clutch.
*twisting the clutch release pinion by hand with clutch cable off was "click, click" back and forth 1/2".
*clutch box apart appears in good condition.
*plates seem fine, but haven't taken them ALL out.

[ihalterman]

Make sure you put the plates back in the exact same order and faceing. I sounds like the Vertical shaft is slipping on the horizontal shaft. I have put clutches back in in the wrong order/faceing and they burn out quickly.

If disk 1 side A faces out when you dissasemble it it has to face out when you put it back together. The disks and plates will where on each other in a specific way.

Hope this was a little help.

BJ

[Jethro]

Is the bike running? Has it not been running for a long time? Sometimes the plates seize a little to each other and the plates don't spin independently of each other.

[david]

Is the bike running? Has it not been running for a long time? Sometimes the plates seize a little to each other and the plates don't spin independently of each other.

yes, i just recently got it running again. But not rolling, obviously without the clutch.
I got the bike in peices and have put it together while learning. With a little help from friends.
It sat for years in a backyard, then sat (in pieces) for another while the man who was going to rebuild it lost his spare time. It's been a great project!! My first.

I do know now that pulling the clutch cable wasn't moving the pressure plate.
Don't know if it would make THAT big of a difference,,, but i doubt the cable was adjusted exactly according to the Clymer.