Late model 8N clutch won't disengage

bergmanj

New User
Folks,

I've gone through about 3 hrs worth of past posts today on this very subject; but, I've taken the steering box off to view the mechanics of the linkage, fork, and throw-out bearing: Nothing seems to be lose or cracked; yet, the throw-out bearing pressure-plate fingers-contact surface is spaced between 3/4 & 1" to the fingers when fully retracted. And, it just "touches" the fingers with the clutch "fully disengaged" and adjustment to it's shortest spacing. What is that "normal" fully retracted/clutch engaged spacing with the TO/carrier & fork all the way back?

Have any of you needed to put a spacer behind or "over" (in front of) the TO bearing to get the mechanism to work correctly?

What is the original thickness of the throwout bearing? Measurements I've seen are 0.840" (original), 0.796", 0.780", etc., from various manufacturers. The only "common" measurement seems to be the inside diameter to properly fit onto the bearing carrier. Seems to me that these various bearing thickness variations would make a big difference in clutch adjustment/operation. I have not yet been able to actually measure MY TO bearing thickness; so, I don't know what's really in there. I'm working outside and can't look now due to rain/snow. Comments??

And, in just moving things around by hand in there yesterday, I noticed that near all the way back (retracted) the TO bearing carrier seemed to have a slight "hang-up" (~1/8") if rotated slightly. Which brings me to another question: Is there any kind of keying on the transmission "snout" and bearing carrier to prevent rotation of the carrier; or, is it just a smooth bore?

Yes, I know that I may need to split it and actually measure for the 2" finger to flywheel height; just trying to avoid the split, if possible; as, I've never done a split before; and, I do not have any concrete pad to do the split on. Suggestions for splitting on earth ground??

Any comments / questions / concerns very welcome.

Thanks, JLB
 
Give us a little history. What happened between last working & not working? Changes? etc.
 
With the wheels blocked, engine OFF, transmission in neutral...clamp the clutch down to the footboard and
then crawl under the tractor. Look up at the external linkage as it is attached to the clutch shaft.
There is a pin through the link to the shaft. See if there is a crack in the link passing across the pin
hole visible from the bottom. The crack can close when the clutch is released. I broke my tractor open
3 times before being told about this concern 40+ years ago.
 

No history from me - bought it 1-1/2 yrs ago from a reputable (personally known) used dealer (he's died since). Clutch was always very "tight" & JUST able to disengage; now won't.

I [i:6b26deee4f]can[/i:6b26deee4f] tell you that the pressure plate has no visible surface rust - so, I don't expect "sticking" from moisture. And there is no sign of it having been split before - I think that the pressure plate is "original"; though, not known for sure.

My main questions are still as to what "normal" spacing is between throw-out bearing and PP fingers; what is/was original TO bearing thickness; whether anyone has used spacers behind TO bearing (I know that there are shims available to space flywheel from crankshaft flange - which would do the same thing); and, any suggestions as to how to "split" on earth/ground surface.

Thanks, JLB
 
Splitting on the ground can work. I would suggest at least one 4x8 sheet of 1/2, preferably 5/8 plywood to do this on. Level is needed.
Once you pull it apart, the only thing keeping the motor from spinning on the front axle pivot is centered gravity and some wedges you can
stuff it to keep it from spinning on the axle pivot.
Got that?
I used a bottle jack under the engine to keep it level and a rolling floor jack under the trans to pull it back about a foot once the sheet
metal and bolts are pulled.
To align it again for reassembly, a few 3/8 x 16 thread bolts, (your's might be different) about 6 inches long (overkill) helped to bring the
trans back straight. If it gets close but no cigar, engage the PTO and give it a spin.
 

Thanks, Bruce, that's helpful. And, yes, I'm well aware of clutch alignment issues from having done many manual car/truck transmission/clutch replacements over a lifetime. Actually "eyeballing" usually works IF you're very careful to get it accurately centered.

Any specific answers as to my questions from anyone else regarding TO bearing thickness, shimming of TO bearing and/or flywheel, engaged spacing between PP & TO bearing, etc?

Thanks, JLB
 
(quoted from post at 18:39:06 04/27/18)
No history from me - bought it 1-1/2 yrs ago from a reputable (personally known) used dealer (he's died since). Clutch was always very "tight" & JUST able to disengage; now won't.

I [i:29d39e2433]can[/i:29d39e2433] tell you that the pressure plate has no visible surface rust - so, I don't expect "sticking" from moisture. And there is no sign of it having been split before - I think that the pressure plate is "original"; though, not known for sure.

My main questions are still as to what "normal" spacing is between throw-out bearing and PP fingers; what is/was original TO bearing thickness; whether anyone has used spacers behind TO bearing (I know that there are shims available to space flywheel from crankshaft flange - which would do the same thing); and, any suggestions as to how to "split" on earth/ground surface.

Thanks, JLB

Don't try to compensate for a problem, fix the problem. Have you checked the rivets on outside of housing and check for cracks , check for broken rivet in fork inside that moves the throw out bearing. Splittin is not that hard and Bruce gave you some good tips. HAve you check and or adjusted free travel of clutch pedal? sounds like all you got is free travel tho.
 
(quoted from post at 22:39:19 04/27/18)
Thanks, Bruce, that's helpful. And, yes, I'm well aware of clutch alignment issues from having done many manual car/truck transmission/clutch replacements over a lifetime. Actually "eyeballing" usually works IF you're very careful to get it accurately centered.

Any specific answers as to my questions from anyone else regarding TO bearing thickness, shimming of TO bearing and/or flywheel, engaged spacing between PP & TO bearing, etc?

Thanks, JLB
/4 to 1 inch is probably about 15 times too much space. I feel almost certain that you will ultimately find a linkage problem.
 
(quoted from post at 08:08:21 04/28/18)
(quoted from post at 22:39:19 04/27/18)
Thanks, Bruce, that's helpful. And, yes, I'm well aware of clutch alignment issues from having done many manual car/truck transmission/clutch replacements over a lifetime. Actually "eyeballing" usually works IF you're very careful to get it accurately centered.

Any specific answers as to my questions from anyone else regarding TO bearing thickness, shimming of TO bearing and/or flywheel, engaged spacing between PP & TO bearing, etc?

Thanks, JLB
/4 to 1 inch is probably about 15 times too much space. I feel almost certain that you will ultimately find a linkage problem.

Plus one on JMOR's advice. I will add that based on my personal search for the cause of a similar problem it may be impossible to "eyeball" the defect without the aid of an assistant who can operate the clutch while you do the eyeballing of the moving components [b:a9f0f6b325][u:a9f0f6b325]UNDER LOAD[/u:a9f0f6b325][/b:a9f0f6b325] and up close and personal.

TOH
 
Many thanks Folks,

I wasn't talking about "eyeballing" broken or loose linkage: I was talking about having been many times successful about centering the clutch plate by "eyeball" in the past without the need of a centering tool.

I also wasn't asking whether 3/4 to 1" was too far back for the TO bearing (I already know that it is way too wide): I was asking what the measurement actually IS under "normal" adjustment conditions (e.g., 1/8", 1/4", 0.100", etc?); does anybody know? If so, what is it (or, what is the "acceptable" or "typical" range)?

And, I asked about TO bearing thickness (replacements vary from 0.840" (original???), down to 0.750" from what I have found available under the same O. E. part number, as stated previously; and, the up-to 0.090" differences must make for some difficulty in clutch adjustment; any specific comments with actual measurements in this regard?

How about the question about flywheel and/or TO bearing shims; especially because of the various thinner TO bearings available as compared to the (apparent) original measurement of 0.840" as above? And flywheel shims are also available to adjust for re-surfaced/out-of-spec. flywheels & crankshaft flanges. Comments from anyone who's actually used either?

I [i:893d3edf3b]know[/i:893d3edf3b] that there may very well be issues with fork and/or clutch lever cracking and/or loose/sheared pins from my hours of research here on many previous posts; I've not asked about those issues because of my previous research - I'm really [i:893d3edf3b]not[/i:893d3edf3b] wanting to try and "reinvent the wheel" here, as a lot's already been covered multiple times in previous posts; only need answers (if anyone knows) to the previous very specific questions.

I really [i:893d3edf3b]do appreciate[/i:893d3edf3b] the interest and offered help; but, I've still not gotten actual answers of measurements, which is what I'm [i:893d3edf3b]really[/i:893d3edf3b] needing here.

Thanks, JLB
 
(quoted from post at 19:04:44 04/28/18) Many thanks Folks,

I wasn't talking about "eyeballing" broken or loose linkage: I was talking about having been many times successful about centering the clutch plate by "eyeball" in the past without the need of a centering tool.

I also wasn't asking whether 3/4 to 1" was too far back for the TO bearing (I already know that it is way too wide): I was asking what the measurement actually IS under "normal" adjustment conditions (e.g., 1/8", 1/4", 0.100", etc?); does anybody know? If so, what is it (or, what is the "acceptable" or "typical" range)?

And, I asked about TO bearing thickness (replacements vary from 0.840" (original???), down to 0.750" from what I have found available under the same O. E. part number, as stated previously; and, the up-to 0.090" differences must make for some difficulty in clutch adjustment; any specific comments with actual measurements in this regard?

How about the question about flywheel and/or TO bearing shims; especially because of the various thinner TO bearings available as compared to the (apparent) original measurement of 0.840" as above? And flywheel shims are also available to adjust for re-surfaced/out-of-spec. flywheels & crankshaft flanges. Comments from anyone who's actually used either?

I [i:d2b4a9f24d]know[/i:d2b4a9f24d] that there may very well be issues with fork and/or clutch lever cracking and/or loose/sheared pins from my hours of research here on many previous posts; I've not asked about those issues because of my previous research - I'm really [i:d2b4a9f24d]not[/i:d2b4a9f24d] wanting to try and "reinvent the wheel" here, as a lot's already been covered multiple times in previous posts; only need answers (if anyone knows) to the previous very specific questions.

I really [i:d2b4a9f24d]do appreciate[/i:d2b4a9f24d] the interest and offered help; but, I've still not gotten actual answers of measurements, which is what I'm [i:d2b4a9f24d]really[/i:d2b4a9f24d] needing here.

Thanks, JLB

Why do you think there is such a measurement? What would it tell you that you don't already know?
 
(quoted from post at 23:11:10 04/28/18)
(quoted from post at 19:04:44 04/28/18) Many thanks Folks,

I wasn't talking about "eyeballing" broken or loose linkage: I was talking about having been many times successful about centering the clutch plate by "eyeball" in the past without the need of a centering tool.

I also wasn't asking whether 3/4 to 1" was too far back for the TO bearing (I already know that it is way too wide): I was asking what the measurement actually IS under "normal" adjustment conditions (e.g., 1/8", 1/4", 0.100", etc?); does anybody know? If so, what is it (or, what is the "acceptable" or "typical" range)?

And, I asked about TO bearing thickness (replacements vary from 0.840" (original???), down to 0.750" from what I have found available under the same O. E. part number, as stated previously; and, the up-to 0.090" differences must make for some difficulty in clutch adjustment; any specific comments with actual measurements in this regard?

How about the question about flywheel and/or TO bearing shims; especially because of the various thinner TO bearings available as compared to the (apparent) original measurement of 0.840" as above? And flywheel shims are also available to adjust for re-surfaced/out-of-spec. flywheels & crankshaft flanges. Comments from anyone who's actually used either?

I [i:4254c628f4]know[/i:4254c628f4] that there may very well be issues with fork and/or clutch lever cracking and/or loose/sheared pins from my hours of research here on many previous posts; I've not asked about those issues because of my previous research - I'm really [i:4254c628f4]not[/i:4254c628f4] wanting to try and "reinvent the wheel" here, as a lot's already been covered multiple times in previous posts; only need answers (if anyone knows) to the previous very specific questions.

I really [i:4254c628f4]do appreciate[/i:4254c628f4] the interest and offered help; but, I've still not gotten actual answers of measurements, which is what I'm [i:4254c628f4]really[/i:4254c628f4] needing here.

Thanks, JLB

Why do you think there is such a measurement? What would it tell you that you don't already know?
S!
 
no need to be a smart a$$ dude you and us all know the thing is worn out just fix it right and go on about your happy tractoring JS
 
Never was trying to be a S. A. (but there is a retort, saying "better than being a dumb ___!", which I won't say here).

Just wanted actual specification information to very specific questions. From my viewpoint, if folks don't know an answer, they should say so rather than keep repeating what is known from previous research originally stated to having already been done.

Also, I've only recently posted this one set of questions; but, have been a member for many years now. Even though some folks may see "newbie" here, I'm well experienced in various mechanical issues: Which is why the above specific questions were asked. Please remember that we are [i:c256a1f4d2]all[/i:c256a1f4d2] (self included) very ignorant in very much more than we are knowledgeable about.

One other thing: Few posts may indicate "newbie" status on many different forums; but, from my experience on several of a wide variety of other forums the only difference between some "gurus" an some "newbies" is the number of posts, NOT the [i:c256a1f4d2]quality[/i:c256a1f4d2] of information proffered; this seems to be the case here from a couple of late comments. Basically Jr. High bullying attempts: Where "NS" means "No $h!t", without offering any further actually helpful information.

JLB
 
(quoted from post at 13:28:08 04/30/18) Never was trying to be a S. A. (but there is a retort, saying "better than being a dumb ___!", which I won't say here).

:lol: my mom and i used to have that same exchange pretty regularly :)

as for your frustration, i understand. i've experienced similar on occasion here.
 
OK, how experienced are you with a calculator, as I gave you the clearance info very early on. 3/4 divided by 15 = 0.050"
An even better answer is, just enough that the throughout bearing isn't spinning when foot off of the clutch. You should know that the dimension you asked for is not specified...the manual says that you should adjust for 'free petal travel of 3/4".
I'm sure it will wrinkle your feathers, but people have given you good solid info, but you continue to 'look for pizz ants to stomp while being trampled by the elephants'. Stop with the minutiae and get on with solving the problem as has been advised. People will help if you focus on the problem and not run off into the ditch.
 
Never was trying to be a S. A. (but there is a retort, saying "better than being a dumb ___!", which I won't say here).[/quote]

HJF - Thank You!

In the meantime, since no one here had the actual answers, I did the engineering calculations (see physics - levers and fulcrums, and trigonometry); which I hope may be helpful to others here in the future.

Turns out that the calculated [i:333a7881d8]total[/i:333a7881d8] linkage ratio (from center of clutch pedal to TO fork contact fingers center is about 3.75:1; i.e., 3/4" pedal movement is equal to ~ 0.200" with the adjustable linkage adjusted to mid-point (about 45 degrees- and, of course, varies a bit [very little - really] with change of angles at adjustment extremes; not the 15:1 as JMOR estimated - off by about 4:1.

For those who [i:333a7881d8]want[/i:333a7881d8] to be "finicky" (perhaps me), this presents an alternate way to verify "free-play" at 0.200" through the opening after removing the steering gear.

I have since verified those calculations by actual measurement after splitting the tractor yesterday (our first nice day in quite a while for working outside). [i:333a7881d8]Nothing[/i:333a7881d8] was found wrong with any of the linkage; the (very original) pressure plate finger points of rotation (hinge points) were all worn a lot - which explains the (in)operation. And, I verified that [i:333a7881d8]my[/i:333a7881d8] original TO bearing measures 0.796" thickness.

Most measurements were made with a tape measure and "eyeball" as accurately as can be made that way, not with machinist gauges; therefore the reason that they are stated as "about". The TO measurement was made with a machinist caliper - so, should be reasonably accurate.

I can see where TO's of other thicknesses and/or crank and/or TO bearing shims could be of good use to someone trying to [i:333a7881d8]adjust[/i:333a7881d8] for a certain amount of wear and tear and/or PP/Clutch plate manufacturing differences from original design specs.

This is actual real measurable information: hope it's helpful to others here in the future.

Regards, JLB
 
(quoted from post at 15:48:35 04/30/18) Never was trying to be a S. A. (but there is a retort, saying "better than being a dumb ___!", which I won't say here).

:lol: my mom and i used to have that same exchange pretty regularly :)

as for your frustration, i understand. i've experienced similar on occasion here.[/quote]otal[/i:d53acffdb0] linkage ratio (from center of clutch pedal to TO fork contact fingers center is about 3.75:1; i.e., 3/4" pedal movement is equal to ~ 0.200" with the adjustable linkage adjusted to mid-point (about 45 degrees- and, of course, varies a bit [very little - really] with change of angles at adjustment extremes; not the 15:1 as JMOR estimated - off by about 4:1.

For those who [i:d53acffdb0]want[/i:d53acffdb0] to be "finicky" (perhaps me), this presents an alternate way to verify "free-play" at 0.200" through the opening after removing the steering gear.

I have since verified those calculations by actual measurement after splitting the tractor yesterday (our first nice day in quite a while for working outside). [i:d53acffdb0]Nothing[/i:d53acffdb0] was found wrong with any of the linkage; the (very original) pressure plate finger points of rotation (hinge points) were all worn a lot - which explains the (in)operation. And, I verified that [i:d53acffdb0]my[/i:d53acffdb0] original TO bearing measures 0.796" thickness.

Most measurements were made with a tape measure and "eyeball" as accurately as can be made that way, not with machinist gauges; therefore the reason that they are stated as "about". The TO measurement was made with a machinist caliper - so, should be reasonably accurate.

I can see where TO's of other thicknesses and/or crank and/or TO bearing shims could be of good use to someone trying to [i:d53acffdb0]adjust[/i:d53acffdb0] for a certain amount of wear and tear and/or PP/Clutch plate manufacturing differences from original design specs.

This is actual real measurable information: hope it's helpful to others here in the future.

Regards, JLB[/quote]k, so much for the tangents, ....where is your initially stated 3/4 to one inch problem? Any progress on that?
 
Where am I at? Re-read my last post above - mid-paragraph already explained what I found.

JLB
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p.s. Pressure plate very worn "finger" pivot points - for those who can't, won't, or don't comprehend the re-read.

New clutch kit on way for installation.

And I will be posting more actual measurements when new PP is installed.
 
(quoted from post at 20:43:22 04/30/18) Where am I at? Re-read my last post above - mid-paragraph already explained what I found.

JLB
.

.

.

.

.

.

.

.

.

.

p.s. Pressure plate very worn "finger" pivot points - for those who can't, won't, or don't comprehend the re-read.

New clutch kit on way for installation.

And I will be posting more actual measurements when new PP is installed.
o, if I did in fact read you correctly, the PP finger pivot points were found to be worn enough to yield an additional one inch of movement/clearance. Is that correct?
 
.

.

p.s. Pressure plate very worn "finger" pivot points - for those who can't, won't, or don't comprehend the re-read.

New clutch kit on way for installation.

See how easy that was
 
I initially posted for good information for some very specifics - and, I stated that I had already done 3 hrs. of research in hopes of not having to "re-invent the wheel".

It would have been a lot easier for all had my original questions actually been answered with real specifications - or, simply said "I don't know": I could have determined immediately what the problem actually was and had the parts coming for my split yesterday and I would have had it fixed and running right now.

The "Guestimate" offered was off by a factor of 4 - how useful was that?

Instead I now have to wait for parts; the wait for good weather, again - not forecast until next Monday - with tractor work waiting now.

Some of you are so very frustrating in not giving the information asked-for. This, and past, "lectures" and "No S___'s" in these posts were totally unnecessary and unappreciated!

So, [i:708d761d1e]no[/i:708d761d1e] thanks,

JLB
 
Keep your shirt on! Nobody here made it that way, and blaming someone else for all your maladies says alot about you. It's a simple tractor with simple fixes. The clutch was flat wore.out from the get go and you knew that. Your excessive and useless analysis of the problem blinded you to correct fix for some time. And now you feel the need to n lay that off on others. If I had a son acting like you I would give them a hell.of a kick in the rear end for starters.. Loose the hubris pal.
 
(quoted from post at 19:47:12 04/30/18) I initially posted for good information for some very specifics - and, I stated that I had already done 3 hrs. of research in hopes of not having to "re-invent the wheel".

It would have been a lot easier for all had my original questions actually been answered with real specifications - or, simply said "I don't know": I could have determined immediately what the problem actually was and had the parts coming for my split yesterday and I would have had it fixed and running right now.

The "Guestimate" offered was off by a factor of 4 - how useful was that?

Instead I now have to wait for parts; the wait for good weather, again - not forecast until next Monday - with tractor work waiting now.

Some of you are so very frustrating in not giving the information asked-for. This, and past, "lectures" and "No S___'s" in these posts were totally unnecessary and unappreciated!

So, [i:d64209b61a]no[/i:d64209b61a] thanks,

JLB
You can be pretty sure that going forward you will be on your own, I for one will not attempt to help you in any way.
 
(quoted from post at 23:16:17 04/30/18) Fine, quit baiting - you're not worth it!

fin.
oesn't pass the 'smell test', but that is OK Junior, in time all passes. :roll:
 

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