stuck differential lock

[LittleBearMan]

I have a MF 175 and the differential lock is stuck in the engaged position. Any suggestions as to how to deal with this??

thanks,
Lou

 

[Anonymous-0]

Try pressing each brake individually while driving or backing up. You could also spray penetrating oil on the pivots for the diff lock.

 

[LittleBearMan]

Thanks, MF175, I will try those.

 

[LittleBearMan]

How bad is this for the tractor if I can't get the differential lock to release??

 

[DavidP, South Wales]

Hi,
Potentially very bad. Likely scenario; You are on concrete or tarmac with a heavy implement mounted on the tractor. You need to make a sharp turn quickly. Possibility 1, you turn the wheel and the tractor remains moving almost straight ahead. Poss 2, Because the rear wheels are unable to turn at different speeds to make the turn you are likely to shatter the dog clutch which is the differential lock or shear the bolts in part of the differential hub. It will require soaking with penetrating oil or similar.
Depending on what type of pedal shape you have a tool should be made to fit the pedal so that it gives you in effect an extension handle on the pedal. If you can get a small amount of movement on the pedal, more oil and patience should be rewarded. It is likely to become free-er but not free enought to return itself. Tie a piece of rope around the pedal end. Sit in the seat. You can push the pedal down with your foot and pull it back up with the rope. Again patience and oil will be needed. If you are unable to free it the axle housing will need to be removed so that you can strip the linkage.
Better to be permanently dis-engaged rather than engaged.
DavidP, South Wales

 

[LittleBearMan]

Wow, thanks very much for the information. All of my work is on soil, but I knew that this was potentally bad. I will get started with the oil and leverage. Thanks

 

[LittleBearMan]

How much force can be applied to the pedal/arm without damaging it??

 

[DavidP, South Wales]

Hi,
Can't give you a figure but only sensible force depending on the length of the handle you make up.
15 to 18 inches would be a guide.
DavidP

 

[LittleBearMan]

Okay, thanks.

 

[LittleBearMan]

Well, I managed to work the pedal arm loose. It takes some effort to get it to move, but it will. I noticed that the pedal arm does not move directly up and down, but has a sideways movement. It appears that the sideways movement is intended to move a large pin mounted on top of the axle. The pin seems to be stuck in the outermost position, which if my logic is correct, has the axle lock disengaged. Is this enough information for you to offer an opinion? Thanks so much for all of the advice.
LittleBearMan, Lebanon, MO, USA