Ford 8N Clutch Problem

[k1000]

I just got my new to me 8N back together after installing new gears and other parts along with a new clutch. I adjusted the clutch pedal per the 3/4" free play rule and after getting the tractor running it seemed fine for the first few clutch engagements but then all of a sudden it snapped free and the pedal went to the floorboard with no resistance and the clutch engaged. I could not get it to disengage until I shut off the tractor, removed the clevis pin at the pedal linkage at which point the clutch rod rotates fully clockwise and seems to "reset" once I reinsert the linkage pin. But then it will just randomly break free. It almost got me when I had it in gear and the clutch snapped and took me on a wild ride out of the garage and almost into my neighbors shed before I got the key off. Could this be a release fork pin that has sheared? That's what I am suspecting at this point.

 

[ZANE]

See if the lever( yoke) that is pinned to the clutch throwout bearing shaft is turning the shaft. It may be that the pin is broken that retains the lever to the shaft.

If not then the pin or set screw in the throwout bearing retainer / fingers may be loose or broken.

 

[k1000]

I marked the yoke position relative with the shaft using a black marker and it seem to be rotating with no slippage, yoke to shaft. It feels like there is a pin or bolt that is sheared but still has just enough of a nub left that it finds the hole and holds for a little while until it gives and slips free. It looks like I am going to have to split for the third time in the last Month. I also noticed when I pulled the pin from the yoke, I was able to slide the whole shaft out by about 3/4". I didn't pull too hard because I was thinking I could possibly pull the whole shaft out if the release fork is partially loose from the shaft.

 

[lastcamp2]

I hope you post your progress on this. I have a similar problem and haven"t figured out how to get the shaft the yoke is on out of the tractor. Let me know how you go about this.

 

[cbradio]

I know that if you have any oil coming out of the engine, it can gum up the clutch and it will stick and not come out of engagement when hot/warm.

Quick 'maybe it works, maybe it doesnt' solution is to spray a solvent into the sight window on the clutch to try and degrease it. not sure if it works, never tried it.

Second, best but significantly more work, solution is to split the tractor and clean it as well as possible replacing the oil sump seals.

Guru's feel free to correct my noob knowledge where needed.

As others have indicated, it could be a mechanical issue too and not a leak issue.

 

[k1000]

I just replaced the rear crank rope seal
so I doubt its leaking. At least I haven"t
seen any oil dripping around the rattler
hole. Besides that, it disengages fine
once I pull the pedal yoke pin and let it
rotate back with the throwout bearing
release fork springs. It just won"t stay
disengaged with the clutch pedal
depressed.It just snaps loose through the
pedal and engages the clutch and the pedal
looses all force against the clutch
pressure plate.

 

[k1000]

The way I figure is that it seems like it
could be only one of two things. 1. The
throwout bearing release fork is slipping
on the clutch shaft under load or 2. The
throwout bearing somehow is slipping past
the pressure plate fingers. 2 seems
unlikely because if the bearing did slip
past I wouldn't think it would reset so
easy by disconnecting the pedal linkage
outside the tranny case and letting it
rotate under its own return spring force.
Is there some other potential cause that I
am missing? These tractors are really
simple but I have only owned this for a
couple of Months so I may be missing
something. I am trying to decide whether
to tackle it by going down through the
steering box hole or splitting again. I've
already rebuilt the steering box so I know
what to expect but I hate the idea of
pulling the dash, brand new wiring
harness,etc. I'm thinking the front split
is the lesser of two evils since I am
getting pretty good at it.Had both front
and back crank seals replaced in one day a
couple of weeks ago.

 

[k1000]

I've pretty much convinced myself to do surgery from the top through the steering box access hole. I will try to get pictures as I go. I am thinking I'll try and tackle it in the next week if the temps here in Iowa don't get too low where my kerosene heater can't keep up. I am hoping that I can get access to the internal fork release pin or bolt from the top side and repair/replace as needed.

 

[TheOldHokie]

(quoted from post at 18:57:49 12/19/13) I've pretty much convinced myself to do surgery from the top through the steering box access hole. I will try to get pictures as I go. I am thinking I'll try and tackle it in the next week if the temps here in Iowa don't get too low where my kerosene heater can't keep up. I am hoping that I can get access to the internal fork release pin or bolt from the top side and repair/replace as needed.

There is no access from the top - the fork is inside the bell housing. Split the tractor - it is not a huge job although working in the cold is never fun. If the pin is sheared, and it sounds like it is, it won''t come out without a fight....

TOH

 

[k1000]

When I had the tractor apart the first time, I
removed the dash and steering box and the fork,
clutch and throw-out bearing was clearly visible
from the top. Underneith the steering box is open to the inside of the trasmission and bell housing.In fact, I had split the tractor as
well and once I joined the engine back to the
tranny, I was sticking my hand through the top
access to line up the splines on the shaft to the
clutch. The front part of the transmission housing
,(where a Sherman would go) is wide open. The
first time I adjusted the clutch, the steering box
was off and I was looking down from the top
watching when the throw-out bearing make contact
with the pressure plate. At least that's what I
remember. Am I missing something here?

 

[carlntexas]

To me it's easier to split it than to take steering box off. It wont be easy working on the yoke through the top.

 

[k1000]

Yea, I think you're right. A split it is. The only
real reason I don't like splitting is because I keep
having to remove the two head bolts that hold the
spark plug wire tube. I have to do this to pull back
that part of the harness to move the engine away.
Maybe I should just pull the wiring out and re-feed
it on re-assembly. All the heavy work doesn't bother
me but I cringe each time I remove those two bolts.
The thought of snapping head bolts scares the crap
out of me.

 

[TheOldHokie]

(quoted from post at 20:26:01 12/19/13) When I had the tractor apart the first time, I
removed the dash and steering box and the fork,
clutch and throw-out bearing was clearly visible
from the top. Underneith the steering box is open to the inside of the trasmission and bell housing.In fact, I had split the tractor as
well and once I joined the engine back to the
tranny, I was sticking my hand through the top
access to line up the splines on the shaft to the
clutch. The front part of the transmission housing
,(where a Sherman would go) is wide open. The
first time I adjusted the clutch, the steering box
was off and I was looking down from the top
watching when the throw-out bearing make contact
with the pressure plate. At least that's what I
remember. Am I missing something here?

Nope - I just never had an 8N apart and while it's been quite a while I don't think that is true of the 9N's. I assumed the transmission housings were the same in that regard so my bad.

But I have removed a sheared release fork pin and it was not something you could easily do through a little hole in the top. Hard enough with full access from the front....

TOH

 

[k1000]

There is one good reason I had for splitting the
first time in that I was able to convince the wife
it would be wise to purchase a cherry picker to be
on the safe side. Maybe this time, I cam convince her
I need a better floor jack to help with maneuvering
this time. Yea.. I'll give that a shot...
A few years ago I got a new welder when her front yard flower holder broke and somehow I talked her into a welder to fix it. I can't believe she went for that, but what the hey! Must have been a weak moment. Eventually she is going to figure out my game. hehe

 

[carlntexas]

(quoted from post at 21:19:39 12/19/13) There is one good reason I had for splitting the
first time in that I was able to convince the wife
it would be wise to purchase a cherry picker to be
on the safe side. Maybe this time, I cam convince her
I need a better floor jack to help with maneuvering
this time. Yea.. I'll give that a shot...
A few years ago I got a new welder when her front yard flower holder broke and somehow I talked her into a welder to fix it. I can't believe she went for that, but what the hey! Must have been a weak moment. Eventually she is going to figure out my game. hehe

ou don' have to unhook all those wires if you take the 4 bolts out that hold the SB on and leave it on the front end. The box needs to be raise a couple of inchs to clear the bell-housing, but you have a cheery picker. You could probable use a new floor jack though. I split mine like this to put a clutch in you can do a search on here and find out more.

Here is a picture with mine split.

 

[k1000]

Thanks for the tip. I'll try it that way this time.
Looks like less work especially not having to lift
the hood off and all.