MF35 Locked up (z134)

[shaeff]

Ugh.

So here's the scenario-

I was using the flail mower to cut down some tall grass, cut some paths through my field. Was running the machine for maybe 1.5-2hrs. Temp gauge never moved, oil pressure good, radiator full, and clear of debris, oil is full.

I noticed it was starting to feel low on power, like when I'd get into tall grass it would bog down and the governor wouldn't pull the RPM back up. I disengaged the flail and was just going to bring it back up to the house. As I'm moving up a small grade in 3rd low, it started to bog even for that. I shut it off immediately at that location out in my field. The machine sat there overnight. I went out the next morning to fire it up, it turned a tiny bit and just stopped. The starter still works fine, but when it engages the flywheel it binds up tight.

Here's the information to know:
- it's not the starter
- I can normally spin this motor (z134) by hand off the fan when in neutral. I cannot.
- I tried to spin it over by the crank pulley. I cannot
- I tried to bar it over off the flywheel. It's stuck, It won't move.
- I tried a huge adjustable wrench off the PTO shaft on the flail with the PTO engaged, it will not move.
- The plugs look great, it was running beautifully prior to this
- No oil or coolant in the cylinders
- I can't see anything concerning in the cylinders with an inspection camera, but the camera I'm using isn't that great.
- I removed the front mounted hydraulic pump (MF35 Utility with a loader on it), the pump spins freely
- I can spin the PTO by hand when it's disengaged
- The machine tows fine in neutral, rear wheels spin freely.

Is my next step to pull the head? Any other suggestions before I go that route? It *could* use a valve job, so I'm not opposed to pulling the head. I already have the hood and gas tank removed for better access.

The thing that gets me, it was running when I shut it down. Now it's stuck. I'd think that it would at least turn by hand. The motor didn't feel hot either.

Open to suggestions. Hoping it won't need an in-frame kit, but if it does, I'll do it.

Thanks

 

[MTGreen]

I think a key piece of information here is that you can't get the PTO to move which leads me to believe that it may not necessarily be the engine, especially when you know it's not hydrolocked because you looked in the cylinders and chances are low that your pistons rod and crank bearings are seized if the engine didn't get hot and the oil doesn't smell burnt. I'm wondering if there's something to do with the clutch locking up to the engine or something else in the drivetrain. You could try seeing if there's an inspection plate in the clutch housing and have somebody actuate it while you look with your camera to see if the clutch is functioning correctly. You could also pull the tractor in neutral with another piece of equipment and see if the rear tires turn or skid

 

[shaeff]

I think a key piece of information here is that you can't get the PTO to move which leads me to believe that it may not necessarily be the engine, especially when you know it's not hydrolocked because you looked in the cylinders and chances are low that your pistons rod and crank bearings are seized if the engine didn't get hot and the oil doesn't smell burnt. I'm wondering if there's something to do with the clutch locking up to the engine or something else in the drivetrain. You could try seeing if there's an inspection plate in the clutch housing and have somebody actuate it while you look with your camera to see if the clutch is functioning correctly. You could also pull the tractor in neutral with another piece of equipment and see if the rear tires turn or skid

Edited the first post to include more info:

I can get the PTO to move if it's disengaged. It spins freely by hand just like normal. The clutch disengages normally, I did check that under the inspection plate. The machine also tows fine in neutral, I just had a buddy of mine steer it out of the field while I towed it and the rear wheels spin freely with no binding. I'm fairly certain the issue is engine related.

It's been suggested on another forum that maybe it spun a rod bearing and when I shut it down it just stuck.

 

[MTGreen]

Edited the first post to include more info:

I can get the PTO to move if it's disengaged. It spins freely by hand just like normal. The clutch disengages normally, I did check that under the inspection plate. The machine also tows fine in neutral, I just had a buddy of mine steer it out of the field while I towed it and the rear wheels spin freely with no binding. I'm fairly certain the issue is engine related.

It's been suggested on another forum that maybe it spun a rod bearing and when I shut it down it just stuck.

Makes sense. Good luck!

 

[redman135]

hmmm that sounds familier.
Did the engine sound clatter just before you turned it off?
When you tried to start the next day, did the engine screech then sieze?
It sounds like you may have run a bearing shell.

If you have run a bearing shell, then by turning the engine off you may have saved your self a big bill. It is still a major job as you will need to remove the engine (WEDGE the front axle so it does not flop over) and pull the crank (tractor sumps are VERY HEAVY, mind your toes) Best case you only need to polish the crank and replace the bearing shells.

I had this problem on my MF135. The extra metal on the crankshaft came from the bearing and the crankshaft itself was undamaged, just a polish job I was told.
Since you have to split the tractor check the clutch and espesially the pilot bearing as well.

Reassembly tip to mate engine and gearbox, (for 6 and 8 sp gearbox) engage pto and as you bring the 2 halves togather, have an assistant rotate the pto to line up the splines with the clutch, and it goes in easily (does not work with multipower gearbox).

 

[shaeff]

Engine sounded fine before shutting it down. No odd noises or anything. In fact, it was idling perfectly fine too.

When I went to crank it over a good 18hrs later, it sounded like it turned a tiny bit and stopped. Another forum I'm on (YT) one of the guys there suggested the same- spun bearing. I was hoping to avoid all that, but if it needs a rebuild, there's no better time than this winter to tear it down. The key is to get the motor in my basement and on an engine stand before the snow flies. I'm aware of the potential for the front to flop over without the axle wedged, but thanks for the reminder. If I end up having to pull it all apart, I'll be replacing the leaky rear main seal, checking the clutch for oil exposure from that leaky seal, tidying up everything that needs it.

Thanks for the tip on the PTO trick, that'll be helpful.

 

[Jerry/MT]

Ugh.

So here's the scenario-

I was using the flail mower to cut down some tall grass, cut some paths through my field. Was running the machine for maybe 1.5-2hrs. Temp gauge never moved, oil pressure good, radiator full, and clear of debris, oil is full.

I noticed it was starting to feel low on power, like when I'd get into tall grass it would bog down and the governor wouldn't pull the RPM back up. I disengaged the flail and was just going to bring it back up to the house. As I'm moving up a small grade in 3rd low, it started to bog even for that. I shut it off immediately at that location out in my field. The machine sat there overnight. I went out the next morning to fire it up, it turned a tiny bit and just stopped. The starter still works fine, but when it engages the flywheel it binds up tight.

Here's the information to know:
- it's not the starter
- I can normally spin this motor (z134) by hand off the fan when in neutral. I cannot.
- I tried to spin it over by the crank pulley. I cannot
- I tried to bar it over off the flywheel. It's stuck, It won't move.
- I tried a huge adjustable wrench off the PTO shaft on the flail with the PTO engaged, it will not move.
- The plugs look great, it was running beautifully prior to this
- No oil or coolant in the cylinders
- I can't see anything concerning in the cylinders with an inspection camera, but the camera I'm using isn't that great.
- I removed the front mounted hydraulic pump (MF35 Utility with a loader on it), the pump spins freely
- I can spin the PTO by hand when it's disengaged
- The machine tows fine in neutral, rear wheels spin freely.

Is my next step to pull the head? Any other suggestions before I go that route? It *could* use a valve job, so I'm not opposed to pulling the head. I already have the hood and gas tank removed for better access.

The thing that gets me, it was running when I shut it down. Now it's stuck. I'd think that it would at least turn by hand. The motor didn't feel hot either.

Open to suggestions. Hoping it won't need an in-frame kit, but if it does, I'll do it.

Thanks

I had a ring gear come off my TO-30 and wedge between the flywheel and the bell housing and it locked the engine up. The engine was a Z129 and it turned out someone put a flywheel from an early production TO-20/Z120 engine on it. It turns out the early TO20's had the ring gear sweated on from the rear. Every time the starter drive hit the ring gear it was trying to push it off the flywheel and it eventually would.
Ferguson changed the design by sweating it on from the front and machining a ring at the back to prevent the starter from knocking it off the fly wheel. I still have the ring gear and the old flywheel and the ring gear was tack welded on to the flywheel. the tack welds were not strong enough.
The other issue is that the electrical system was converted to 12V and the original 6 V starter was used. The addition torque of the starter contributed to the problem.

The fix was to find a re-designed flywheel (which I did) and install that. No more problems.

That's a long way to tell you to remove the starter and look at the ring gear to make sure it is still on flywheel.

 

[shaeff]

I had a ring gear come off my TO-30 and wedge between the flywheel and the bell housing and it locked the engine up. The engine was a Z129 and it turned out someone put a flywheel from an early production TO-20/Z120 engine on it. It turns out the early TO20's had the ring gear sweated on from the rear. Every time the starter drive hit the ring gear it was trying to push it off the flywheel and it eventually would.
Ferguson changed the design by sweating it on from the front and machining a ring at the back to prevent the starter from knocking it off the fly wheel. I still have the ring gear and the old flywheel and the ring gear was tack welded on to the flywheel. the tack welds were not strong enough.
The other issue is that the electrical system was converted to 12V and the original 6 V starter was used. The addition torque of the starter contributed to the problem.

The fix was to find a re-designed flywheel (which I did) and install that. No more problems.

That's a long way to tell you to remove the starter and look at the ring gear to make sure it is still on flywheel.

That’s pretty wild! I did get around to pulling the clutch inspection plate. The ring gear is still on the flywheel. Can’t spin it from there either.

 

[Jerry/MT]

That’s pretty wild! I did get around to pulling the clutch inspection plate. The ring gear is still on the flywheel. Can’t spin it from there either.

You might want to look from the starter end. As I recall I had to look pretty hard to find that the ring gear was "out of plane".

 

[5030]

Sounds like a dropped valve to me.

 

[shaeff]

You might want to look from the starter end. As I recall I had to look pretty hard to find that the ring gear was "out of plane".

Will do, certainly easier than dropping the pan.

Sounds like a dropped valve to me.

That would be ideal, easy fix as long as it didn't really screw anything up. I didn't see anything out of the ordinary when I looked in the cylinders, but the inspection camera I used left a lot to be desired.

 

[5030]

Easy to ascertain without removing anything but the valve cover. Remove it and visually inspect the overhead. If there is a dropped valve, you'll see the stem will be higher than the rest and it will be an exhaust valve, not an intake.

 

[shaeff]

Easy to ascertain without removing anything but the valve cover. Remove it and visually inspect the overhead. If there is a dropped valve, you'll see the stem will be higher than the rest and it will be an exhaust valve, not an intake.

Hoping to pull the cover this weekend. I’ll post some pics if I get around to it. Thanks!

 

[rScotty]

That's one of my favorite old tractors. A friend had one for 40 years or more. Gasser. Needed nothing - except he perpetually wished for Power Steering. Like a lot of machinery from that era, they were designed to be worth keeping forever.

Returning to that rebuildable philosophy of mechanical design would solve a lot of climate and economic problems.

Anyway, getting off my soapbox.. I hope to follow along as you take a look in the engine, and hope you will post some photos.. One thing I wondered is it locked against rotation in both directions?
Also, I suppose you have lifted the rear tires and rotated them by hand to make sure that the lock is in the engine and not the clutch/transmission.
rScotty

 

[shaeff]

That's one of my favorite old tractors. A friend had one for 40 years or more. Gasser. Needed nothing - except he perpetually wished for Power Steering. Like a lot of machinery from that era, they were designed to be worth keeping forever.

Returning to that rebuildable philosophy of mechanical design would solve a lot of climate and economic problems.

Anyway, getting off my soapbox.. I hope to follow along as you take a look in the engine, and hope you will post some photos.. One thing I wondered is it locked against rotation in both directions?
Also, I suppose you have lifted the rear tires and rotated them by hand to make sure that the lock is in the engine and not the clutch/transmission.
rScotty

This one has been great, I’ve owned it since 2015 and put hardly anything into it except rebuilding the hydraulic system in the rear and a solid tune up with electronic ignition.

It’s definitely in the motor, the transmission/rear is all free.

I pulled the valve cover today, I don’t have much for free time.

 

[shaeff]

Had more, not sure if I accidentally deleted.

 

[rScotty]

Nice pictures, the first thing that leaps out at me there is do I see green grass? In NY in November?

On the rocker shaft & valves I don't see anything obviously amiss. Do you?
A couple of little things:

I do see a little bit of carbon crust on the what I think are the exhaust valve springs. That's a sign of a some blow-by past the valve guides and valve stems. Pretty common in engines with lots of hours. In fact I've seen much heavier carbon buildup on old low compression engines that ran just fine. So that's expected and not the problem.

Hmm.....Is that wear on ends of the rockers where they push on the valves?? I can't tell if I am looking at wear or shadowing.....looks like wear. Again, consistent with lots of hours. Or they could have been made that way. If wear, one of them has a lot of it though I'm not familiar with that particular engine and that style of forked rocker to say for sure from photos.
But I don't see signs of anything that would lock it up. I didn't expect to.

On one of what I think is an exhaust (last photo, center) has excessive tappet clearance - but not as much as I'd expect if it would have if had struck the piston hard enough to lock up the engine.

Next move it it were mine would be to pull the plugs and look inside the cylinders. That might even be worth getting a borescope to look around. Price on some of those has come way down on Amazon. Some USB type are less than a head gasket. not I don't know much about them & not used one on an engine yet, but it seems better than pulling a head for no reason.
And that tool would give you a better view in the bell housing to see if anything came loose - like one side of the ring gear that several mentioned.

It's looking more and more like you will be dropping the pan.

rScotty

 

[shaeff]

Nice pictures, the first thing that leaps out at me there is do I see green grass? In NY in November?

On the rocker shaft & valves I don't see anything obviously amiss. Do you?
A couple of little things:

I do see a little bit of carbon crust on the what I think are the exhaust valve springs. That's a sign of a some blow-by past the valve guides and valve stems. Pretty common in engines with lots of hours. In fact I've seen much heavier carbon buildup on old low compression engines that ran just fine. So that's expected and not the problem.

Hmm.....Is that wear on ends of the rockers where they push on the valves?? I can't tell if I am looking at wear or shadowing.....looks like wear. Again, consistent with lots of hours. Or they could have been made that way. If wear, one of them has a lot of it though I'm not familiar with that particular engine and that style of forked rocker to say for sure from photos.
But I don't see signs of anything that would lock it up. I didn't expect to.

On one of what I think is an exhaust (last photo, center) has excessive tappet clearance - but not as much as I'd expect if it would have if had struck the piston hard enough to lock up the engine.

Next move it it were mine would be to pull the plugs and look inside the cylinders. That might even be worth getting a borescope to look around. Price on some of those has come way down on Amazon. Some USB type are less than a head gasket. not I don't know much about them & not used one on an engine yet, but it seems better than pulling a head for no reason.
And that tool would give you a better view in the bell housing to see if anything came loose - like one side of the ring gear that several mentioned.

It's looking more and more like you will be dropping the pan.

rScotty

Yeah, it's been pretty mild here. I'll take it, although the ticks are out in full force when the weather is this mild.

I don't notice anything glaring, however it does seem that almost all of the rockers are nearly on the same plane. Tough to tell, I'll have to put a straight edge on it. The loader frame is pretty in the way at this point, but I'm only pulling the loader if I need to.

From what I know about this machine, it's never been apart. I was quite happy when I pulled the valve cover and it was as clean as it is, but yes, there's definitely some blow-by.

The rockers are definitely a bit worn, too. Again, I'm with you, don't see anything that would cause the machine to lock up. The head is coming off regardless, it needs to be redone. I get lots of oil leakage into cylinder 4, I'd like to get that taken care of.

Glad you noticed that last pic as well. There's also a small piece of maybe a shim or something that broke off and was sitting on the other side of the head. You can see it in the second to last pic on the right side.

I tried to look into the cylinders, the inspection scope I used wasn't small enough to really see what's going on. Again, with the oil leakage on #4, the head is coming off regardless. I'll put some bolts and washers in the block to hold the sleeves in, then see if it turns over. Worth a shot, but I doubt it at this point.

I still don't know if it could be a dislodged ring gear- the machine was down on power (not overheating, still full of oil) before I shut it off. There were no odd sounds or anything. It ran when I shut it off, turned maybe 1/8-1/4 of a turn with the starter the next morning and that was it. Locked.

 

[shaeff]

Easy to ascertain without removing anything but the valve cover. Remove it and visually inspect the overhead. If there is a dropped valve, you'll see the stem will be higher than the rest and it will be an exhaust valve, not an intake.

See anything in the pics I posted above that looks concerning to you? I'll be pulling the head regardless, as I get some oil into #4 so I want to fix that once I find out where this issue is and how much it's going to cost me.

 

[rScotty]

Nice pictures, the first thing that leaps out at me there is do I see green grass? In NY in November?

On the rocker shaft & valves I don't see anything obviously amiss. Do you?
A couple of little things:

I do see a little bit of carbon crust on the what I think are the exhaust valve springs. That's a sign of a some blow-by past the valve guides and valve stems. Pretty common in engines with lots of hours. In fact I've seen much heavier carbon buildup on old low compression engines that ran just fine. So that's expected and not the problem.

Hmm.....Is that wear on ends of the rockers where they push on the valves?? I can't tell if I am looking at wear or shadowing.....looks like wear. Again, consistent with lots of hours. Or they could have been made that way. If wear, one of them has a lot of it though I'm not familiar with that particular engine and that style of forked rocker to say for sure from photos.
But I don't see signs of anything that would lock it up. I didn't expect to.

On one of what I think is an exhaust (last photo, center) has excessive tappet clearance - but not as much as I'd expect if it would have if had struck the piston hard enough to lock up the engine.

Next move it it were mine would be to pull the plugs and look inside the cylinders. That might even be worth getting a borescope to look around. Price on some of those has come way down on Amazon. Some USB type are less than a head gasket. not I don't know much about them & not used one on an engine yet, but it seems better than pulling a head for no reason.
And that tool would give you a better view in the bell housing to see if anything came loose - like one side of the ring gear that several mentioned.

It's looking more and more like you will be dropping the pan.

rScotty

I see that shim.... no idea at all. Not only do I not know what it is, I can't figure out where it would have come from. It has to be part of the rocker gear.. right?? And where is the rest of it?

I looked around online to see if I could find an exploded view or parts diagram for the motor and couldn't find one. If you know of a link, let me know. There does seem to be a parts dealer in Canada whose website seems promising.

What I was looking for was to see if a picture showed anything in the front cam drive/timing cover that could explain a sudden lockup.
If the timing is by gears and the rest of the shim got caught between two gears it is one of the few things that might explain what happened to yours so suddenly and without even running.
I keep coming back to the only clue you have - that it was running fine and then the starter moved it just a little and no more. Maybe it is something simple in the bellhousing/starter system.

The problem I have with anything in the head and bore locking things up is that I would think you ought to have been able to at least rock the engine a few degrees of rotation with your pry bar. Well we will know eventually.

My inspection scope isn't small enough to fit through a spark plug hole either or into the bell housijng - it's a 75 foot for 4" drain lines. Chinese. Quite surprisingly good quality and well made.
I see quite a few mechanic's endoscopes for under $50 on Amazon that are USB type made to plug into a laptop computer.
That is still on my Christmas list, but before I get one I'd have to have some sort of idea of what features to look for. I'm trying to slow down on buying tools just to satisfy a one-time curiosity bump (hopeless, I know) and I know nothing about mechanic's scopes.
rScotty