Need help fixing my tractor

Reddog5175 · Mar 25, 2016

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 · Mar 25, 2016

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 · Mar 25, 2016

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 · Mar 25, 2016

Dave M7040 said:
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 · Mar 25, 2016

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 · Mar 25, 2016

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 · Mar 25, 2016

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 · Mar 25, 2016

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 · Mar 25, 2016

Eagleview said:
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.