Need help fixing my tractor

[Reddog5175]

I have a Mitsubishi MT250D 4x4 tractor. Iwas using it and heard a clunk sound and it wouldn't move. I split the tractor to check the clutch and found the pressure plate fingers broken so I replaced the entire clutch assembly ie.. pressure plate, clutch disc, pilot bearing and throwout bearing including having a new hub machined that holds the throwout bearing. I put the tractor back together and the clutch works as it should, I can shift gears and the PTO shifts as it should and the output of the PTO spins as it should.

My problem is that when I put the tractor in any gear and let the clutch out the tractor won't move, no matter what gear. I thwen split the tractor again to see if any splines or shafts were stripped or broken and all seem in good shape. I have taken the cover off the tranny to see if there is any damage and all looks good, no metal or shavings in the fluid either..

Since I have it split between the rear end and the tranny, I can manually put the tranny in any gear, when I spin the shaft by hand it won't spin ( as would be expected ) When I spin the shaft to the rear end, one wheel tries to roll, when I block that wheel, the opposite wheel tries to spin ( appears the rear end is working )

I am really hoping someone can tell me what might be wrong or what I should check next. If the tractor is low on fluid, would this cause the tractor not to move? Thank you in advance for helping.

 

[bcp]

Welcome to TBN.

I am totally unfamiliar with your transmission, but to me it seems that it may a shift fork problem causing you to actually be in two gears at once.

Bruce

 

[Dave M7040]

I agree with bcp.
Your transmission is in two gears at the same time.
Take the cover off and try to get all gears into the neutral position. In this position all the shift forks should be lined up.
Take a picture if you can
Dave M7040

 

[Reddog5175]

I agree with bcp.
Your transmission is in two gears at the same time.
Take the cover off and try to get all gears into the neutral position. In this position all the shift forks should be lined up.
Take a picture if you can
Dave M7040

I do have a pic of the tranny with the top of the case off. I attached it. Hope it helps

 

[Dave M7040]

I have marked up your photo with some colored arrows to help me explain what I see,

The red arrow and the yellow arrow point to synchronizers which slide to either side to engage a gear.
The two green arrows show the possible gear positions for the red arrow synchro.
In this case the synchro is in the middle and not selecting a gear.
The yellow arrow synchro only has one blue arrow because the synchro ring is slid to the left engaging a gear.
Try sliding this one to the center position.
I cannot see the lower part of the gears so I am assuming you are in reverse plus one forward gear.
I hope this will give you n idea of what to look for.
Can you post a photo of the inside of the cover?
Dave M7040

 

[s219]

To me it looks like the collar on the right is fully engaged with the gear to its left.

The collar on the left looks partially engaged with the synchro to its left, enough to be grabbing that gear. I'd say try to re-center the collar on the left and see what happens. May want to run through all the gears to make sure the forks behave and let you get in and out of all gears. Looks like a 4-speed, or maybe 3 with reverse I can't see??

 

[s219]

Edit: what Dave calls synchros I call collars. To me, the synchros are the toothy-rings to each side of the collar, between the collar and the true gear.

 

[Eagleview]

I see a clutch pack on the mainshaft , I'll bet that is where the trouble is . Either the friction discs are shot or the splines are torn out . That Blue heat mark should not be there either .

 

[Reddog5175]

I see a clutch pack on the mainshaft , I'll bet that is where the trouble is . Either the friction discs are shot or the splines are torn out . That Blue heat mark should not be there either .

I think I need to clarify my problem a little. I installed the new clutch, put the tractor back together and it fired right up. I pushed the clutch in and it felt fine. I pushed the clutch in, shifted into 1st gear, let the clutch out and the tractor wouldn't move. I did this in all 3 gears and reverse and it won't move. If I leave the tranny in gear ( any gear ) and push the tractor it will roll like it is not in any gear. I then shifted the PTO into the 2 different RPM, let the clutch out and the PTO output spins as it should.

If I parked it on a hill, put in any gear and pushed it, it would roll down the hill so I know the tranny is not locked up. What are friction discs ? can they be replaced and if splines were torn up wouldn't there be metal shaving /pieces in the fluid?

I really appreciate all the input.

 

[BertZegers]

Seems to me your clutch is not engaging.

 

[Dave M7040]

Seems to me your clutch is not engaging.

After re reading your latest description I agree with those who say the transmission is not locking up by being in two gears.
However, when the first problem is finally solved you will need to ensure the collars are all in neutral to avoid another problem.
Does your tractor have a hydraulic shuttle shift? If so your question about low fluid may have revealed the cause of the problem. The clutch pack to the left side of the picture will require hydraulic pressure to lock it up and transmit power.
I cannot find much info on line about the 250D transmission.
Dave M7040

 

[Eagleview]

I think I need to clarify my problem a little. I installed the new clutch, put the tractor back together and it fired right up. I pushed the clutch in and it felt fine. I pushed the clutch in, shifted into 1st gear, let the clutch out and the tractor wouldn't move. I did this in all 3 gears and reverse and it won't move. If I leave the tranny in gear ( any gear ) and push the tractor it will roll like it is not in any gear. I then shifted the PTO into the 2 different RPM, let the clutch out and the PTO output spins as it should.

If I parked it on a hill, put in any gear and pushed it, it would roll down the hill so I know the tranny is not locked up. What are friction discs ? can they be replaced and if splines were torn up wouldn't there be metal shaving /pieces in the fluid?

I really appreciate all the input.

Hello , I didn't mean the clutch you just replaced , I was referring to the INTERNAL clutch pack that is part of the mainshaft (circled in yellow) It may have an issue , but going on the picture , the friction discs look fine . The blue heat mark behind the clutch pack is a worry though . That blue mark indicates heat and more than likely from slipping clutches .

Your original problem would not have been caused by broken pressure plate fingers . They would cause the clutch to NOT disengage rather than stopping the tractor driving .

I think your original issue was the INTERNAL clutch pack slipping , either because of mechanical damage or the oil pressure pump not supplying pressure to it(depending on if it pressure applied or pressure released , or both) . I wonder if the "clunk" you heard was a pump shaft drive key breaking or something similar ? I think when you found the broken pressure plate fingers , you prevented a different problem taking place in the future

.

 

[joecdeere]

Drive clutch disc installed backwards?

 

[KWentling]

I've worked on mechanically actuated clutches like that in machine tools, and that clutch looks fine to me. As far as the blueing goes, it could be from a heat treating process and be normal, or possibly be from friction from some failure in the actuating part of the clutch. Is this hydraulically actuated? If so you may be able to check its operation with compressed air. I would be looking at that part of the clutch closely.

Kim

 

[DLTTrekkers]

Pedalfreetravel ?

 

[Reddog5175]

I've worked on mechanically actuated clutches like that in machine tools, and that clutch looks fine to me. As far as the blueing goes, it could be from a heat treating process and be normal, or possibly be from friction from some failure in the actuating part of the clutch. Is this hydraulically actuated? If so you may be able to check its operation with compressed air. I would be looking at that part of the clutch closely.

Kim

I have no idea if the clutch pack is hydraulically actuated or not, but I am leaning that direction. that is one of my questions, I have looked online and there is minimal information on the tranny. I am thinking that since all the splines, shafts, bearings etc look good and I did not find any metal shavings/pieces in the fluid, that the machine was low on Hydraulic fluid and won't pressure up the clutch pack to move the machine when in gear.

Is this a possibility? How do I check with compressed air? Thanks again for all the help.

 

[Dave M7040]

I have no idea if the clutch pack is hydraulically actuated or not, but I am leaning that direction. that is one of my questions, I have looked online and there is minimal information on the tranny. I am thinking that since all the splines, shafts, bearings etc look good and I did not find any metal shavings/pieces in the fluid, that the machine was low on Hydraulic fluid and won't pressure up the clutch pack to move the machine when in gear.

Is this a possibility? How do I check with compressed air? Thanks again for all the help.

The pressures required to operate the clutch pack will be much higher than compressed air.
Do you have an owner's manual for your tractor which would provide a clue as to the purpose of the clutch pack.
I had asked before if you had a shuttle shift but you did not answer.
Dave M7040

 

[BertZegers]

Your picture shows only the gearbox, not the shafts going in or out, so I cannot see. But my first thought is that the clutch pack is for the (hydraulic) PTO.
Do you have a (PTO) shaft inside the (drive) shaft for the PTO on the engine side?
If you have the tractor split, you could turn the shafts by hand and see what happens. If the tractor is not split, you could have some one turn the engine by hand, end see what happens in the gearbox. (try "in gear" and try in neutral) If the gears don't turn, its a clutch problem.
Make sure the gears and the gears shifter are in neutral before assembling, and test.

The clutch pack discoloring is from the welding or heat treatment in the factory, I think.

Did you get it fixed already?

 

[Reddog5175]

The pressures required to operate the clutch pack will be much higher than compressed air.
Do you have an owner's manual for your tractor which would provide a clue as to the purpose of the clutch pack.
I had asked before if you had a shuttle shift but you did not answer.
Dave M7040

I have a manual but it doesn't show me much. I am not sure what a shuttle shift is, I have other pictures of the shafts etc where the tractor is split now.

 

[banjodunn]

I agree with an earlier comment about pedal free travel as you have had a new thrust brg carrier machined is it exactly the same as the old one? Also check the clutch plate on the input shaft splines for the correct fit I have assembled one before in a rush and not checked the fit to the spline and found that the box had the wrong plate in it and it would spin on the shaft, also check to make sure there are not transport bolts in the pressure plate these bolts hold the mating face back and allow for easier assembly


Jon