Clutch woes.

[Red_Phil]

Hi All,

My project bikes clutch is still goosed. It's a 1980 GSX400 E.

Originally the plates were stuck so that even with the pushrod pushing the
plates open they still gripped. I managed to persuade them to loosen up though.

Now the clutch operates fine in neutral, but as soon as I shift into a gear
the clutch doesn't want to go out. The lever is slack.
If I go back to neutral and pull the lever lots then eventually the clutch
springs do their job and the clutch grips.
Then it works pretty much fine until I go back into gear.

Sometimes it will go out and grip when in gear but rarely and jerkilly.
I discovered I can wheelie whilst trying this out.

As the bike warms up, the clutch gets worse if anything.

Tonight I opened up the case and took the plates out of the clutch.
I cleaned them of any crap that was on them and oiled them.
I lightly filed off any burrs I could find on the plates and the clutch basket.
Put it all back together and got pretty much the same response.
The basket, the springs and the plates all looked fine.

What is wrong with my clutch? please? anybody?
are the springs that push the clutch closed knackered?
is something else jamming it?
so I need a new set of clutch plates?

help, before I snap and try to fix the bike with a sledgehammer.

[duaneage]

I would start with a look at a repair manual and see that you have the plates properly aligned. There is a pattern to how the dog ears and discs go together. I don't know if you have Clymers manuals in Scotland but maybe another forum member could scan you the pages for a look.

When you put the cover back on, did you have the clutch lever arm connected to the clutch cover? This should be removed so the small gear oin the cover can rotate onto the teeth of the clutch push rod. Again, a manual shows this process better than I can describe it.

Lastly, have you tried to remove the small lever from the clutch rod and reposition it so that you have a different range of motion?

If anything is wrong with it I would guess the puchord is either inserted incorrectly or damaged. Relaxe, take a breath, and try and get a look at the manual first.

[Red_Phil]

Hi duaneage.

I have a haynes manual for this bike.

I put the plates back in the right order.
As far as I could see both sides of the plates were the same so hopefully
it doesn't matter that I may have some of them back to front.

The order of the plates is an odd one.
The manual shows 7 'outside' plates with the fiber pads and dog ears on them. I have 7.
It also shows 7 'inside' all metal plates. I have 6.

This means that one of the plates at the end that should be a metal plate is actually a fiber plate. I suppose this could be the problem.

I believe you may be describing a different clutch.
The pushrod on the 1980 GSX400 E is smooth at both ends.
The clutch actuation lever is attached to the inside of the left side sprocket cover and sits over the end of the push rod when the cover is in place.

The range of motion on the clutch actuation lever seems to have the full range of motion as it is. it uses a setup that allows 4 positions at 90 degrees to each other. I cannot see how the cable could operate it in any of the other positions.

When I had the clutch off, the push rod moved freely with very little resistance, I believe it is probably fine. The plates push apart without problem, the problem comes when the push rod is no longer being pushed and the clutch springs fail to close the clutch.

Thanks for your Ideas, I know remote diagnosis is hard.

[Red_Phil]

Just a thought.

As most of the lower end and transmission is common between the GSX400 and the modern GS500, I was wondering if a GS500 clutch could be swapped into the GS400?

I could probably get a reasonable GS500 clutch from a breakers yard.
A GSX400 clutch is probably like hens' teeth.

[drewshotrodding]

on your bike you should have a fiber plate at each end inside and outside the metal plate with sharp edge facing you when you put them in take your thumb and run it on edge not to hard it may cut you put that all back together loosen the cables on the bike completely start on the bottom on the motor tighten the cables from there than go to the top and make sure that you have about 1/8in play at the lever

[Red_Phil]

Well I've bitten the bullet and ordered new clutch plates and springs.

drewshotrodding :
Tell me more of this sharp edge to identify which way round to have the plates facing.

Do the metal plates attachin to the transmition side of the clutch have an inside and an outside face, or is it just the fiber discs that have a facing?

I take it this sharp edge you mention is on the edges of the dog ears on the fibre plates?

Hopefully this info will help me get the plates back into the basket in the correct orientation.

[duaneage]

Well I've bitten the bullet and ordered new clutch plates and springs.

drewshotrodding :
Tell me more of this sharp edge to identify which way round to have the plates facing.

Do the metal plates attachin to the transmition side of the clutch have an inside and an outside face, or is it just the fiber discs that have a facing?

I take it this sharp edge you mention is on the edges of the dog ears on the fibre plates?

Hopefully this info will help me get the plates back into the basket in the correct orientation.

The clutch metals go one way only, absolutely. I have a 650 four so my clutch IS different, sorry for leading you astray. Tolerances are REAL TIGHT in there, it does not take much to cause a problem either with too loose a clutch or one that won't release.

The metals have a sharp edge if I recall. The clutch plate fibres should be soaked in oil prior to installation.

Break teh clutch in a bit by putting the front wheel to a wall and allowing the engine to work on the plates a little. THis ( I am told) helps to get the adjustment right