Clutch failure (AGAIN!) Ford 1100 4WD

[tosii2]

I've been getting lots of 'good stuff' from the forums on lots of topics, but am finally admitting bafflement on the clutch on my Ford 1100.

I am facing replacing the clutch assembly in my 1100 for the third time because it will no longer disengage. The failures have all been the same; starting with proper free play, the clutch pressure plate doesn't disengage from the clutch disk adequately and I get grinding when shifting. Even adjusting the free play to nothing doesn't give enough 'push' to disengage the disk. I have even tried adjusting it so that the throw-out bearing guide bottoms out on its travel and it still won't fully disengage. Definite symptoms of the clutch spring fingers having lost temper and are flexing too much. Measuring the lift of the pressure plate during the last clutch replacement job showed a dramatic difference in lift between the old and new pressure plates.

What I have read is that this failure is usually due to riding the clutch, slipping the clutch, etc. That could have been the case on the first failure since I was doing a lot of excavating with it (dug a basement in rocky clay soil), but no way on the second one and certainly not the last one!

Since I put the latest clutch in this past spring (and probably less than 50 hrs on it), I was regularly checking free play and paying attention to how I was using the clutch. I really think I was treating it right!

The first clutch lasted for something like 25 years, which was just fine and I had been using it hard, so that was ok. The second one lasted maybe 1 1/2 years, and the current one is starting to go after 6-7 months. The last time I replaced the clutch, there was essentially no thickness loss to the clutch disk; that says to me it wasn't slipping and that wasn't causing heat which would kill the temper of the fingers.

With a new clutch, there seems to be plenty of margin when it is disengaged (eg, pedal not down all the way). This margin just keeps getting smaller and the free play doesn't seem to change.

Some details on the free-play adjustment; since there is more play in the clutch pedal-linkage to the throw-out cross-shaft lever than I really like, I always check at the cross-shaft lever when I adjust free play to make sure that the throw-out bearing isn't quite touching the clutch plate with the clutch pedal up.

So, any thoughts on what I can do differently when I again split the poor thing again and replace the clutch? Somewhere I have to be doing something wrong!

Thanks for any thoughts or pointers to a thread I may have missed !

Terry
-------
Ford 1100; Koyker FEL with massive self-built subframe; dedicated hydraulic pump for FEL driven from crank pulley end.

 

[beenthere]

:welcome:

A bit puzzled here, when you say the clutch will not disengage as being the problem.

You surmise from

What I have read is that this failure is usually due to riding the clutch, slipping the clutch, etc.

Seems to me if/when the clutch plates are worn from slipping the clutch that it would not engage, rather than will not disengage.

So to me, the 2nd and 3rd clutch problem seems to be more about a linkage adjustment, linkage wear, throwout bearing, or something other than clutch facings. You have been in there, so know better than I what might be the problem. But something is keeping the clutch plates from moving away from the driving face.
Do you have a schematic of the clutch and linkage?

 

[JC-jetro]

Welcome to TBN Blue,

on previous repairs, have you replaced the disk only? have you changed the pressure plate with your last replacement?

JC,

 

[svcguy]

Sounds as though the pressure plate fingers are being punched in or bent inward. It's not your clutch plate that is failing, it's your pressure plate - so trying to adjust your clutch to just clear your throw out bearing isn't critical. I would adjust the free play with the pedal, don't worry about linkage. You may be adjusting it with so little free play that you are damaging the pressure plate. I purchased a Kubota that had a stoved in pressure plate from too little free play. I took a hydraulic press and bent all the fingers back out to patch it until a new one arrived that was back ordered. I finally sold the machine with the new pressure plate in a box years ago and the new owner still hasn't needed to replace it. I simply added a bit of extra free play to the clutch pedal and all was well. You don't want to have so much extra free play that the clutch is dragging, but better a bit more than not enough. Remanufactured pressure plates are wishful thinking (regardless of my success), make sure to purchase new replacement parts from your dealer. Always replace a throwout bearing if you split the tractor and be sure to clean and polish the shaft.

 

[Jbrink64]

When you split the tractor, check the engine plate. It's the plate bolted to the rear of the block, and the bell housing bolts to the plate. With a FEL, the plate bends slightly, and puts the engine and transmission out of alignment.

 

[tosii2]

Thanks for the thoughts, folks,
(and I apologize that I left this thread hang; took me a bit to find it again....)
To go through questions, etc
1. when I said that the failure mode was often cited as from riding the clutch, etc I meant that doing so (presumably) had a continual stress on the fingers, thus losing their temper and allowing them to flex too much when the clutch pedal was depressed.
To clarify a bit more relative to linkage, when the clutch plate is new, the throw-out guide is near the end of its travel toward the clutch (it has a 'stop' that won't allow it to go much further than is adequate for a new clutch). If the plate was worn, the fingers would be higher off the clutch plate, giving more margin for the travel of the throw out to disengage the clutch. What is happening right now is that that stop is what limits how far the throw out can depress the fingers, and that isn't enough to fully disengage the clutch.
2. In each replacement, I have replaced the works, plate, disk, throw-out bearing, and the pilot bearing.
3.I checked the new plates against the old; even measured how far the fingers are above the mounting plane of the clutch to the flywheel... The are very nearly identical.
I did an experiment on the last replacement where I rigged up a jig while the tractor was split which which I could depress the fingers. Doing that with the old plate, there was very little movement of the plate away from the disk, I couldn't get a .005 feeler in there. With the new plate, it was very visibly off the disk and I didn't have a feeler big enough to fill the gap. As far as I could tell, I was depressing the fingers about the same in both cases.
4. When I check free play, I do check at the cross shaft to be sure I can feel some play there in addition to setting it by the pedal travel. When I adjust the free play, I can always still feel some play at the cross shaft lever and can hear the internal linkage to the throw out guide touching.
5. all my parts have been new from NH.
6. The thought about the engine plate is a good one; in fact, I did see that happening on the first clutch; I have a FEL mounted, and that was stressing that plate (I have since massively reinforced the whole FEL frame). I straightened the plate during the first clutch job and am reasonably sure it is again flat.
I had wondered if I had an alignment problem causing the disk to hang up on the input shaft, but the experiment with the new vs old plate pretty much says to me that I am somehow stressing the plate itself.

I had also wondered about putting a shim behind the throw out bearing to give more 'throw' to the throwout bearing guide for a new disk, but, darn it, it should work as it is! and I do think I am somehow damaging the plate fingers... unless I got two from a bad batch or something...

I may try to take off the plate underneath the cross shaft to make sure that I am right that the throwout bearing guide is bottoming out, but that entails pulling the front axle out to get the front driveshaft clear of that area. Might be worth it to just confirm that aspect. I DO know I can't get the clutch any more disengaged no matter what I do with the freeplay adjustment; there is a hard stop in there somewhere.

 

[tosii2]

I was just reading through my last post and noticed I wasn't consistent about clutch plate vs clutch disk.
The sentence about '...when the clutch plate is new...' should have been '...when the clutch disk is new....'
The sentence ' ...if the plate was worn..' in that same paragraph should have been '...if the disk was worn...'

In my #6 paragraph. I am talking both about the engine plate and the clutch plate, I am talking about the clutch plate in the last sentence.

One more comment; When I did the first clutch job, there was well over 1/2 the wear left on the original disk (comparing the new vs old height about the rivets). I replaced this clutch because of the 'won't disengage' problem, not because the disk was worn out.

 

[Eagleview]

I don't think you have any problem with the clutch plate or pressure plate at all . They don't behave as you described . As a clutch plate wears , the fingers on the pressure plate move rearward and take up the free play between them and the throwout bearing so the clutch disengages earlier not later .

I think you will find that one or two other things have happened .

1/ The spline in the clutch plate is not free on the input shaft and is preventing the plate from moving away from the flywheel . This causes the plate , input shaft and gearbox to keep spinning with the engine causing grinding of the gears .

2/ The input shaft pilot bearing/bush is tight or seizing which will also keep the input shaft rotating .

If you can get to the input shaft through an inspection hole , try carefully to give it a squirt with penetrating oil using a long nozzle to free it up . Don't get enough on there to get on the clutch . I think you will find that the clutch will now work . This is only a test , it is up to you if you want to leave it be and keep working it or to split the tractor and use Never Seize on the splines .

 

[banjodunn]

G'day have you checked the thrust bearing carrier and fork for wear or movement may not be allowing enough movement to throw the clutch??


Jon

 

[Hooked_on_HP]

I just looked at the parts breakdown on Messicks site and see that the clutch fork is pined on the shaft with a spring pin. Could the pin be worn and the fork isn't moving as far as the shaft is. The clutch disc isn't in backwards is it.
Bill