GS1150 - Clutch SHIM - not valve shim

[londonboards]

We've all had problem noises from our clutches. Loose springs on the back plate has always been cited as a cause but I never got that the rumble was associated with a few loose springs of little weight. Often it's said the the clutch hub nut is loose. But what happens when you tighten this up and the noise is still there?

The drag racing brigade will say it has to do with the helical cut primary gears pushing sideways on the clutch and over time wearing some component that keeps the whole sha-bang nice and tight.

I discovered another reason today and it is the steel insert in the inner clutch hub which has come loose:







And this is what the movement looked like:

So I am swopping that hub out for another that I have.

Now going through the manual for the re-assembly, I see there is a little section on the clutch hub shim, which comes in 4 sizes. I have always thought (on my other GS1100Gs) that the rumbling rattle was caused by movement of one or other or both of the hubs moving laterally along the shaft and not being retained snugly but the clutch hub nut because the underlying spacers where slightly proud and allowing movement. Its seems in these later GS1150/GSX1100 models they introduced shims of different sizes to eliminate this.

This is how it is depicted in the service manual:





I have searched this forum and I can find no mention of these shims.

Does anyone have any experience of eliminating clutch rattle with the judicious use of these shims?

And how exactly do you measure this 0.03-0.08 gap when it is only visible from inside the clutch basket?

Greetings

[tirebiter]

I'm no expert on these bikes but it seems that you need to stack up the appropriate pieces stated in the test from the manual : From bottom to top - oil pump drive gear and spacer, primary driven gear and spacer, washer. The text specifies using a flat surface plate but a countertop of other smooth surface would probably suffice. I've used the anvil surface on the backside of my bench vice for things similar to this.

Apparently you need to do the measurement with the peices removed from the bike. The gap as shown - underneath the washer will be there if the shim is thick enough to push the washer up. If the shim is too large the gap will be excessive. Without seeing it in person (not sure if the 850 clutch and related parts are identical) I would guess that you have to measure the gap with the feeler gauge blade put into place by feel rather than by eyeing where it goes. Maybe the feeler gauge can go in from the side, between two clutch basket prongs.

Reason I'm interested is because I have a 1980 GS850LT that has clutch drag issues and in my bike I realize there seems to be excessive lateral play. The clutch basket seems to move along the shaft by a LOT more than several thou of an inch. More like 1/16" or more, on my bike.

I'll be interested in seeing how you fare.

[Steve]

And how exactly do you measure this 0.03-0.08 gap when it is only visible from inside the clutch basket?

There is a product called Plasti-Gage that is used to measure clearance in crankshaft and rod bearings. Not sure how accurate it would be in your case, but it might work.

It is a soft plastic rod of a specific thickness and works on the principle that when it is flattened, the resulting width will depend on how far it was compressed, You simply compare the width of the squished piece to the chart to see what the clearance is.

It comes in different sizes for the expected clearances, so shop carefully.

.

[rapidray]

Building GS dragbike engines I run into this issue once in awhile. I have a picture somewhere of the shim kit you can buy to shim it correctly. It is a machine shimming kit, NOT a Suzuki part. I have helped a few others with this before but don't remember who. I will try to find the picture & get it up later today.
Ray.

[blowerbike]

the 83 1100 and all 1150's use a shim because the sleeve hub bearing(spacer) is thinner on these model's.
80-82 1100' have a "normal" thickness spacer and no shim from the factory.
the only issue i have had was needing to add a thicker shim is when the back of the inner hub rubs(slams) into the clutch basket and sheers the back off of it.(only happened when beating the hell out of it).
a little bit of rub marks is some what normal under severe use.
99% of the time changing the factory shim was a non issue.
remember with helical gears the clutch basket is always trying to push itself out the clutch cover from the side load.

in the US the 1150 is the only model with the steel sleeve cast into the hub.
from my experience they loosen over time/miles and need replaced.

[blowerbike]

just watched your video on this topic...
the machined look on the basket edge is from a long(wrong) bolt in a through hole on the clutch cover/engine case.
i heard you mention this so i thought i'd pass it along.