Clutch Pressure Plate

[mack]

So I've been working on my spare motor lately and was checking out the clutch and this is what I found. Note that the galling is only present on three of the towers but two of the three are just surface abrassions. The one in the center of this picture however is deeper. I've checked out the center assembly and the holes the pressure plate towers fit through show no signs of contact. All the lands and grooves are pristine. I dry fitted it to gether to look for any play and couldn't find anything.The spider/star is pristine.
I'm having a tuff time getting my ears around what caused this. If the springs weren't properly seated, the spider shouldn't have gone down and seated properly. I confess I didn't pay much attention when taking it apart so I didn't notice anything out of alignment. But because only three are affected, something was a miss.
Any idea's?

[BA80]

That's a mystery mack. There's nothing there but the springs.

The only thing I could say it MIGHT be is someone tried to put spacers under the springs and it didn't work out well. They came apart or slipped out of place and rattled around in there.

[mack]

Investigating

Been thinking about this and have a hypothesis I’m going to try to check out. The only movement for that plate is in and out. The thickness of the galling is about the depth of the movement the throw out bearing would apply when the clutch lever is engaged. That would put the affected area right in the circular holes in the center assembly. But in order for it to make contact with the walls to cause the galling, there would need to be an oscillation. So …… I’m thinking that either the main shaft has runout, or one or both bearings are defective, despite rolling freely by hand. Not sure if I have the ability to check the shaft for runout. I do have a dial indicator but no V-blocks and I’m not sure I can attach the indicator to the case half and use that for a seat to rotate and watch the indicator. I’ll see, but these are what I’ll be checking. I’ll also inspect all the gear surfaces to look for evidence of a similar oscillation. If I’m right that might be why the bike was taken off the road in 88 and declared unroad worthy. It only has about 11K miles on it according to the DMV records. But, if that was the case, it would have had a very bad shake to it at higher rpm.

[mack]

Still investigating

Well I was right about the depth of the plunge on the pressure plate but it isn't enough to have the plate ride out of the lands and groves of the center piece. Your right Greg, it's a mystery.

[James England]

How about weak springs which, instead of compressing evenly when the clutch is pulled in, bend to one side like a banana (if you see what I mean)?

[mack]

Hi James

I measured the springs today and they were all around 41.36mm so the length was ok and they all still had the blue dye on them. But your point is well taken. I'll replace them at the same time as the friction disc's. Which brings me to another point. i measured those disc's today,( at every tab) and they all have more wear in one quadrant( three tabs). I find that weird as well. You would think that the wear would be uniform, but it wasn't.

[TopCatGr58]

Hey Mack,

James' comment got me thinking! Okay, it's surprising that it only has 11K miles but this much wear. You would think that the clutch case cover would not have been taken off. But what I'm thinking is that 1 of the 3 balls in the throwout lever/rod assembly was out of position, and so when the clutch is activated/level pulled, it would push against the throwout bearing/star plate assembly at an angle instead of evenly all around. This could also contribute to the clutch plates not being able to be separated evenly which could also lead to the uneven wear on the frictions. JAT!

T.C.

[mack]

Looking

at the inside of the motor so far, leads me to believe it was used for a lot of quarter mile drags. So it may have had several sets of friction plates and springs put into it. So what I'm seeing now could very well be old damage. It's a really nice motor though, everything cleaned up very well and who ever was shifting the gears knew what he was doing.
Originally it was plugged with crud, road oil, asphalt chips, and stones throughout all the cooling fins and the inside had alot of sludge in the nooks and crannies in the cases and oil pan.
No real damage other than the pressure plate.
I've got lots of plasti gauge, new set of rings, new con rod shells, new main shells if it needs them, and I'll do the washer swap for sure.
Tried to make contact with the guy I bought it off five years ago, but he's moved so no luck there. But the people at the DMV gave me a form to fill out to get title for it. I didn't worry about a bill of sale at the time, because I was only going to use it as parts. But with so few miles on it, and my other bikes all in new condition, I will never need parts so ......once done I may sell it.

Excellent point TC, I'll certainly check out the whole mechanism.

[trbig]

If that shows wear there, be sure to check where the manual says to.. the other half of that where all the clutch plate tabs go. If those slots aren't smooth, but instead look notchy, it can cause clutch problems.

As for the part pictured, it looks to me that it's obviously wear pattern from the springs just by looking at the spacing of the marks. Spring steel is tough stuff, but if the manual doesn't address this, I wouldn't sweat it. If you do, I've got several here.

[mack]

Thanx Big

Thanx big. It in iitself is no big deal. I'm just making sure a more serious problem wasn't present before I closed up the cases.

[trbig]

I think that the way the star plate that you compress the springs with, it's a weird design. The little arms on the outside edge don't really center up the springs. Worst case scenario is a clutch problem later. Although it's a bit of a pain to go back in there, and I understand your wanting to get it right before buttoning up, you can do it on the sidestand and don't even have to drain the oil to get in there to fix it later if need be.

[BA80]

If it was used for drags it's very possible that a spring or 2 broke under the stress. It might be that the plate you have is part of a clutch pack that grenaded and it survived and was reused.

At any rate, I don't think it is part of a current or ongoing issue.

[XS1100_OEM4ME]

Something happened

So I've been working on my spare motor lately and was checking out the clutch and this is what I found. Note that the galling is only present on three of the towers but two of the three are just surface abrassions. The one in the center of this picture however is deeper. I've checked out the center assembly and the holes the pressure plate towers fit through show no signs of contact. All the lands and grooves are pristine. I dry fitted it to gether to look for any play and couldn't find anything.The spider/star is pristine.
I'm having a tuff time getting my ears around what caused this. If the springs weren't properly seated, the spider shouldn't have gone down and seated properly. I confess I didn't pay much attention when taking it apart so I didn't notice anything out of alignment. But because only three are affected, something was a miss.
Any idea's?

Something happened to cause the marks. I am guessing a clutch failure some where in the past. It might work fine and then again it might be out of whack due to the damage. I see these come up on flebay cheep from time to time, or a member may have one cheep. If you do close up and find a vibration, then you will need to start over and fix it again. If you fix it now, you will sleep like a baby JIMHO