Clutch Adjustment

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RBW
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Clutch Adjustment

Post by RBW » Thu Nov 25, 2021 8:27 pm

Hello

I found this thread on clutch adjustment. I still have a few questions if anyone can help.

viewtopic.php?t=272380

Pedal is near vertical when at rest against up stop. Pedal has about 45 degrees of travel before hitting foot basket. About 2/3 of travel is light spring tension, and last 1/3 of travel is heavy spring tension, where clutch actually appears to mostly disengage. I have the short cable clevis adjusted pretty much all the way in. Near the end of travel, the guide ball on the long clutch cable exits the front of the guide tube in the frame crossmember. This causes me to believe the cable is stretched, as I would expect the guide ball to remain within the tube. There is no adjustment at the release fork end of the cable, correct? The manuals (both depot and field maintenance) are frankly not very helpful on this issue. All I could find in the field maintenance manual regarding clutch adjustment was to adjust the yoke to allow "3/4" of clutch pedal free play". I assume this is light spring tension from the release spring? In that case, I have probably 2" of free play, leading me to think the cable is stretched. Also doesn't help that I don't have the original quick disconnects and am using Dorman parking brake cable couplers, so I'm not sure how this is affecting the total length of the cable, since I don't have an original quick disconnect to compare the distance between the ball ends. Thanks for any help.

Curtis


Chuck W.
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Re: Clutch Adjustment

Post by Chuck W. » Fri Nov 26, 2021 8:09 am

There is no adjustment at the release fork end of the cable, correct?
Correct. On stretched clutch cables, I have had luck adding a Dorman parking brake cable adjuster to the clutch cable to give me a little more adjustment.
Image
It's not unusual to find a knot or two tied in the clutch cable in an attempt to take up the slack!

RBW
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Re: Clutch Adjustment

Post by RBW » Sat Nov 27, 2021 5:27 am

Chuck,

Thanks for the reply. I saw the parking brake adjuster in another thread also, and that may be the way to fix it (for now, until I get the machine running and put some time on her). I also saw in another thread the method of heating and twisting the clutch pedal shaft to index the clutch lever key more forward to get more clutch travel. That might also fix it for now, though I think the clutch and brake pedal alignment is mostly correct based on the pictures I can find (mostly from the internet and manuals, since I don’t actually have a correct working Mule). Hour meter says 53 and engine and drivetrain seem to be in good shape, so not sure how cable would have gotten stretched so much if that is remotely true, but it’s impossible to know how much the machine was actually driven.

Chuck W.
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Re: Clutch Adjustment

Post by Chuck W. » Sun Nov 28, 2021 12:36 pm

I also saw in another thread the method of heating and twisting the clutch pedal shaft to index the clutch lever key more forward to get more clutch travel.
I'd think twice about doing that, I did it once and, boy, was that a deep rabbit hole! If the guide ball on the clutch cable is beyond the guide tube, then the cable is too long. It's my opinion that the clutch cables were either manufactured incorrectly or they stretch too easily. I have seen so many mules with the same clutch problem for it to be a coincidence. So, I'm doubtful that even a new clutch cable will fix your problem, and if it does, it may not last long. There needs to be some type of turnbuckle in the cable to allow more adjustment, in my opinion. The parking brake cable adjuster is an easy way to shorten the cable. In the words of Watch Wes Work, it's only temporary unless it works!

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Re: Clutch Adjustment

Post by RBW » Sun Nov 28, 2021 1:15 pm

Chuck,

All good points, I think. Since the brake and clutch levers (not the pedals, but where the clevises attach) are pretty well aligned, as shown in all the pictures I can find, I don't think it best to go about re-indexing these. I'll give the cable adjuster a shot. Thanks for the recommendations.


Curtis

RBW
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Re: Clutch Adjustment

Post by RBW » Sun Dec 12, 2021 5:28 am

Update on this issue - I am using the parking brake cable adjuster mentioned and the clutch is working well. I placed it just aft of the guide tube near the front of the cable. The top of the pedal has 3/4" travel under the return spring tension (light spring around cable on inside of bellhousing), and about 2" of travel with heavy pressure against the pressure plate spring. The cable strands due distort a bit around the cable adjuster hook, but I can't think of a better method right now. Considering the cable can't be unstretched, this makes the most sense. Will be interested to see if the wire rope place in town can shorten and splice it. Non-issue until I take the engine off, which it appears I will have to do as a result of either a transmission input shaft leak or an inner left rear drive shaft outlet seal leak. Thanks for the help with this.


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