I was finally able to return to this project. I investigated your theory that this is a mechanical problem. You were correct. The lift arm shaft is binding in the bushings due to corrosion. Now the challenge is to remove the shaft. I can not drive it out per the service manual. I took it to a MF dealer/shop and they said they usually crack the plate when removing the shaft in this situation and would not attempt it. I decided to drill thru the plate and both bushings and squirt in some penetrating oil. I will see if the makes any progress on freezing up the shaft. Any other thoughts on this are appreciated.
MF 231S Lift arms will not lower
- Thread starter Tjmanitou
- Start date
Harry in Ky
Veteran Member
As I recall the last time I dealt with that it was on a 240. Virtually the same tractor in that regard. What I ended up doing was fabricating a clamp/bracket assembly that I attached to one side of the lift housing around the area of the rockshaft bushing. Then with a long forcing screw from a puller set I pushed the shaft as far as it go (which wasn't very far). Sprayed down the underside of the housing and exposed surfaces of the shaft with penetrating oil. Then moved the assembly to the opposite side and forced the shaft back the other way. Repeating this process a number of times finally got the shaft out. Between the engineering, fabrication, and operation, it took a couple days work. I still have the brackets hanging hanging on a wall somewhere should I ever come across another one like that.
Once I put the holes at the rockshaft bushing and got the penetrating oil in there, I cycled the lift with my brushhog. Now I can lower the arms with just my weight but still not where I want them. I am going to let this sit awhile and periodically add more oil before pulling off the assembly again. I need the tractor for some other work at the moment. Thanks Harry for getting me down the right path.
etpm
Veteran Member
On my Yanmar YM2310 I had a similar problem, a shaft that would not rotate due to corrosion. Though the steel shaft runs in bronze bushings the shaft was stuck because it had rusted and rust takes up about 7 times the volume as the steel it formed from. Though not the same part or tractor the solution is probably the same. I was able, after using penetrating oil, the get the shaft to move slightly. So I would move the shaft, apply oil, move the shaft, apply oil, etc. Eventually I was able to start flushing rust from the bushings. Then more oil could find a way in. I finally got the bushed part off of the shaft. Like you I also put in holes, but only after finally getting the assembly apart. I would have put the holes in first, like you did, except there was no room to get a drill in to drill the holes. I ended up putting in 3 zerk fittings so that I can keep the assembly greased. Because there is no way to keep water from getting to the assembly grease in the bushings is necessary to keep rust from forming.
Eric
Eric
After getting holes drilled and exercising with lots of penetrating oil, it is working well enough to use light-weight implements now. I did end up with two holes per side and at offsetting positions. Added grease zerks and hopefully this will not be an issue any longer.
landinista
New member
Saw this a bit late but I had a MF231 (Polish version) and loved it while I owned it. Bought it used and was never really maintained properly (if at all). I had exactly the same problem with the lift arms - they would only go down with me standing on them in addition to the implement. Someone suggested using PB Blaster over an extended time and manually lifting the arms once I stood on them to fall to lowest position. The last time I did this I heard a 'crack' and that was all it needed to work properly. I did keep using PB Blaster and never had another issue. Also, if you have an air filter with oil canister make sure you keep changing that oil regularly. My MF231 hadn't had that oil changed in who-knows how long and it had become a solid goop like honey. Once I cleaned it out and replaced the oil it started up with a roar (all 39Hp 
) and loads of torque. Finally, make sure the fuel-flow valve is fully opened (on the left side of engine towards the back and about half way up as I recall). Every time the tractor was under load while blowing snow it would stall and I couldn't figure it out until a mechanic came over and noticed it. That tractor was a workhorse from that time onward. Only complaints were the open station was brutal in winter (covered it with plastic over angle iron), didn't have 4WD which I needed for my hilly property, and brakes weren't that great due to contours of my property. I might have an owner's manual if you need it.
) and loads of torque. Finally, make sure the fuel-flow valve is fully opened (on the left side of engine towards the back and about half way up as I recall). Every time the tractor was under load while blowing snow it would stall and I couldn't figure it out until a mechanic came over and noticed it. That tractor was a workhorse from that time onward. Only complaints were the open station was brutal in winter (covered it with plastic over angle iron), didn't have 4WD which I needed for my hilly property, and brakes weren't that great due to contours of my property. I might have an owner's manual if you need it.