WR clutch travel issue


14 replies to this topic
  • filfido

Posted July 10, 2011 - 12:51 AM

#1

Hi All

My clutch cable broke about a month ago. I got the replacement cable, fitted it but the push lever travel was excessive and uses up maybe 50% of the total movement before the clutch starts to engage so all the adjustment has to be taken out of the new cable before it will even start to work.

Took out the push lever, pushrod 1 & 2 and pressure plate to check them over (manual just says look for wear) pushrod 1 assembly (mushroom shaped part) looked like there was a very small amount of wear so I replaced the assembly but problems still there with the new assembly. Everything else in the pushrod assembly looks fine, no wear or distortion.

A couple of months before this I rego'd the bike and was told by the mechanic I should check the clutch as there was a noise coming from it and the clutch could be about to detonate.

So I pulled the clutch apart and checked everything. Housings were all fine, no wear or movement that shouldn't be there. Plates were all flat and in tolerance as were the springs.

Unfortunatly as the clutch was fine before this (good movement, not grabbing/slipping etc) so I didn't pay attention to the push lever positioning so have nothing to reference against.

The slack in the system I need to take up is about 2mm. I could shim it to take up the slack but would sooner know if there's something i'm missing first.

If anyone else has had this problem and solved it i'd appreciate any advice.

  • YamRZ350

Posted July 10, 2011 - 05:55 AM

#2

You didn't lose the little ball bearing when you took it all apart, did you?

  • filfido

Posted July 11, 2011 - 01:09 AM

#3

Nope, made very certain everything that came out went back the same way. I've had a couple of shims turned by one of the toolies at work so I can shim between the ball bearing and pushrod pt1. Its the only way I can see to do it...

  • MANIAC998

Posted July 11, 2011 - 03:57 AM

#4

Stock cable? Stock Clutch Lever? Some of the aftermarket stuff is not made very well. Definately sounds like you've got something going on. Maniac

  • jonooffler

Posted July 11, 2011 - 07:33 AM

#5

Hi mate sorry to hear about your clutch, I have the same thing on mine. No free slack on the lever but with it pulled right up to the bar there is still dragging on the clutch. I have fitted new plates and steels and even fitted a new cable but it's still not right. The basket is fine and free of damage.
I find that after a ride of around 20mins the dragging is so bad that the bike stalls. I'm going to have another go at adjusting the cable tonight ,which I hope will make things a bit better .
Can any one tell me how much free play should you have in the lever .
Jono 2004 WR450

  • William1

Posted July 11, 2011 - 08:25 AM

#6

Nope, made very certain everything that came out went back the same way. I've had a couple of shims turned by one of the toolies at work so I can shim between the ball bearing and pushrod pt1. Its the only way I can see to do it...


Do not shim the push rod. You have to figure out what the problem is. Have you ever removed the cllutch actuation arm (the part the inner cable end attaches to on the engine)?

Is the bracket the cable outter unbent?

Is your lever and perch in good condition (a worn pivot can be a pain)?

  • William1

Posted July 11, 2011 - 08:27 AM

#7

Hi mate sorry to hear about your clutch, I have the same thing on mine. No free slack on the lever but with it pulled right up to the bar there is still dragging on the clutch. I have fitted new plates and steels and even fitted a new cable but it's still not right. The basket is fine and free of damage.
I find that after a ride of around 20mins the dragging is so bad that the bike stalls. I'm going to have another go at adjusting the cable tonight ,which I hope will make things a bit better .
Can any one tell me how much free play should you have in the lever .
Jono 2004 WR450

freeplay should be the thickness of a nickel at the perch. Again, a lever and perch must not have any slop.
It is common for the clutch to tighten up when it gets hot and loosen when cooled off. If you slip it less, it will not tighten as much.

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  • filfido

Posted July 12, 2011 - 05:26 AM

#8

Hi William 1

I know shimming isn't really the way to go and I need to find the root cause (call it the last act of a desperate man!).

All the clutch parts, lever, cable are standard and the pivot is in good condition. The problem seems to be in the degree of rotation of the actuator before the pushrod 1 assembly contacts the pressure plate. I removed the actuator arm to check for wear after changing the clutch cable and had too much movement in the system.

I've attached a link to a few images to better illustrate what I mean.
You can see in the images the rest position of the actuator arm and the degree of rotation needed just to bring the pushrod into contact with the clutch pressure plate.
There's a couple of shots to show the freeplay between the pushrod and pressure plate.
Image of pushrod 2, there's a machining mark on the end of the pushrod where I assume the rod has been held during manufacture (its dead centre and too small for the ball bearing to fit inside of).
Image of the actuator arm and a closeup of where it meets the pushrod, there's a small amount of wear on the edge but it doesn't seem significant, there's no grooves or anything apparant just the machining marks.
Image of the inside of the pressure plate, bright mark where the pushrod touches but no steps or apparant wear to cause this.

The only other thing I could think would cause this is if the clutch inner was too far back in the basket but this could only really happen if i'd forgotten to refit the thrust washer when I checked the clutch (which I'm certain I did fit it). Also the clutch plates and pressure plate all align correctly (which wouldn't happen if i'd done that) and the clutch was working nice and smooth before the cable snapped, progressive with no grab or drag.

Any feedback would be much appreciated.

http://s1132.photobu...o/WR450 clutch/

  • miweber929

Posted July 13, 2011 - 02:43 AM

#9

Hi William 1

I know shimming isn't really the way to go and I need to find the root cause (call it the last act of a desperate man!).

All the clutch parts, lever, cable are standard and the pivot is in good condition. The problem seems to be in the degree of rotation of the actuator before the pushrod 1 assembly contacts the pressure plate. I removed the actuator arm to check for wear after changing the clutch cable and had too much movement in the system.

I've attached a link to a few images to better illustrate what I mean.
You can see in the images the rest position of the actuator arm and the degree of rotation needed just to bring the pushrod into contact with the clutch pressure plate.
There's a couple of shots to show the freeplay between the pushrod and pressure plate.
Image of pushrod 2, there's a machining mark on the end of the pushrod where I assume the rod has been held during manufacture (its dead centre and too small for the ball bearing to fit inside of).
Image of the actuator arm and a closeup of where it meets the pushrod, there's a small amount of wear on the edge but it doesn't seem significant, there's no grooves or anything apparant just the machining marks.
Image of the inside of the pressure plate, bright mark where the pushrod touches but no steps or apparant wear to cause this.

The only other thing I could think would cause this is if the clutch inner was too far back in the basket but this could only really happen if i'd forgotten to refit the thrust washer when I checked the clutch (which I'm certain I did fit it). Also the clutch plates and pressure plate all align correctly (which wouldn't happen if i'd done that) and the clutch was working nice and smooth before the cable snapped, progressive with no grab or drag.

Any feedback would be much appreciated.

http://s1132.photobu...o/WR450 clutch/

This was asked before, but OEM plates, cable, lever and perch? Anything not OEM needs to be replaced with OEM or you could be chasing a non-issue.

I purchased a clutch cable from Motion Pro years ago that was supposed to fit my 84 XR250R and, well, didn't 100%. It worked but had too much freeplay, etc. Bought an OEM one, $5 more and fit perfect.

Not knocking MP, as I have purchased more since then, they are just not always 100% right fit.

Mike

  • MANIAC998

Posted July 13, 2011 - 03:55 AM

#10

You just said everything was working perfectly before the cable snapped? So the only thing that changed was the cable? Then there's got to be something wrong with that cable! Did you install the cable, find that it didn't work properly, and THENtear into the system? Does your clutch have one of those smaller clutch plates that uses an inner spring washer in conjunction with it? We need more info. Maniac

  • filfido

Posted July 13, 2011 - 04:12 AM

#11

Hi All

Its a 2006 WR450, Clutch is as shown here: http://www.boats.net...UTCH/parts.html

As I didn't really pay attention to the actuator position when the old cable was fitted as it worked fine (only adjusted it from the bars until it snapped) I don't have a point of reference but I don't think the clutch cable is the issue.
If you refer to the images I posted the rotation of the actuator before the pushrod engages with the pressure plate is excessive, its prob half way between the install position and the bracket that locates the clutch cable which indicates too much freeplay (or my screw up) in the clutch system itself rather than a problem with the cable.

I'm off work tomorrow so I think I might take another look at the clutch itself rather than the pushrods and see if there's anything I missed....

  • MANIAC998

Posted July 14, 2011 - 04:34 AM

#12

Part #7 has my interest. It's half of the steel plate configuration. I've never noticed that on my U.S. model. Do you have any means of accurately measuring your plates? Maniac

  • filfido

Posted July 24, 2011 - 06:57 AM

#13

Hi All

Well I did a bit of investigating and fettling over the last week and came up with some interesting results.
I took a look at a couple of friends WR's (both running OEM cables) and as I kind of suspected the amount of available cable coming out of the outer sheath is less on the OEM cable compared to the aftermarket replacement I have and the actuator arm is engaging in a similar position to what I was experiencing.
So I drew up a little spacer part and had it turned up at work, trimmed back the rubber gator on the end of the cable to stop it bunching up and put it all together. Worked a treat and back on the road. I've uploaded a couple of images here: http://s1132.photobu...lutch solution/
So before I put everything back together I got out the vernier & micrometer and measured all the clutchplates and compared this against the tolerance ranges in the manual. Then I worked out the distance travelled by the pushrod for the angular rotation in the actuator and how much movement was used when the lever was pulled back to the bars. Then I cruched the numbers and worked out that before my clutch actually needs replacing there won't be enough rotation left in the actuator to engage it fully!!
I suspect that the difference between the OEM and aftermarket cables may be because Mr Yamaha is accounting for a bit of an oversight during the design of the system. Rather than change the parts in the clutch its easier (and cheaper) just to change the length of the cable.
I suppose the lesson here has been only use OEM parts (even cables) and if you don't then expect to have to do some tinkering to make things work..

Thanks to all for the comments and suggestions

  • filfido

Posted July 24, 2011 - 07:10 AM

#14

Hi Maniac
I hadn't noticed that. My workshop manual only makes note of one steel plate rather than the two shown in the parts list, would be interesting to know what the difference is as this may be part of the problem if they're different thicknesses?
I always keep the plates in order so they go back in the same sequence they came out.
I measured mine with a micrometer and took them into work to use the surface plate in the toolroom to check they weren't warped.

  • MANIAC998

Posted July 25, 2011 - 03:59 AM

#15

Glad to hear you've got it figured out finally! That's exactly why I stay away from the aftermarket stuff! Sometimes there "quality control" leaves a little too much to be desired!!! Maniac




 
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