MF50A drive issue

[sled dog]

Oil checked with dipstick OR hex plug on side

 

[sled dog]

Stuck shift valves could cause this, but hard to think both are stuck...

 

[BILLYMAN62]

Thanks Dog. The fluid is looking discolored, not emulsified but colored and smells old and stale. Tomorrow I will pull the back plug at rear of transmission, have been syphonig out the front where I cannot get allen heads to break loose. Problbly could with grips, I might try in the morning, PB blasted the suckers and going to go apply some more. I am hoping the trans shift lever only moves under preasure, because it still feels locked down tight. Maybe some action in the old bread basket, might free it up. I got hopes, and that's about it.

 

[BILLYMAN62]

The two shifters have good smooth action. It is the Trans shift valve arm I am having issues with. But it may very well not shift back and forth, unless under pressure. Will finish the draining and then re-fill at least once and see if anything changes. I may have to check the other filters mentioned.

 

[BILLYMAN62]

Update - oil changed in trans diff. no change in performance. I do hear slight grinding while shifting sticks on transmission but do slip into gear easy enough. But at this point, no action to the wheels. I am still of the belief that the control valve arm is locked up somehow. Does anyone have any suggestion as to how to possibly free it so that it moves. The lower arm works freely when not attached to the control valve arm. And the name alone sounds like what I am not getting fluid through the vale or directed whatever its function is.

 

[Tinkerer]

It may have a sheared (failed) flex plate on the engine flywheel.
When they fail the engine no longer turns the torque convertor.

 

[BILLYMAN62]

but would that cause the arm or valve controller to be locked in one position?

 

[BILLYMAN62]

• I read this online - does this make sense to anyone?

• Including results for how to free the transmission control valve arm on massey ferguson 50a.
  Do you want results only for how to free the transmission control vale arm on massey ferguson 50a?

• These models have a different hydraulic control. Some came without a filter so It is not uncommon for a small piece of trash to get in the control valve and cause it to stick. To check that, drain the oil down below the bottom bolt hole of the access plate on the side with the dipstick. Remove the access plate. Move the quadrant levers to be sure the linkage is moving the vertical levers which hang down from the lift cover. There are two small levers coming up from the pump with a roller between them. With the pump turning, reach in and push the small levers towards the back of the tractor as far as they will move. Then release them, That will usually free the control valve.

 

[Delmer]

That link brings up directions for TO20-mf50-65 etc. MF made a 50 tractor I believe, that is between a 35 and 65, but completely different hydraulics from this 50A. I think that's a wrong turn. My 50A only goes 1/2" foward and 1/2" back, I assume that's normal. I would check the basics before digging into the hydraulics further.

 

[sled dog]

Billyman62, it's time for a pressure check. 5 inches up from the shift shaft on the side of the bell is a small pipe plug. Tap in there with a minimum of a 400 lb gauge. You want to see 150 psi at 1000 rpm. Lets find out if the pump is working. Also, the shift shaft runs thru a caged needle bearing. If the tractor has set a long time, or if that bearing has not been greased, that may be why it wont move. All the shaft does is move a spool up and down to direct oil to forward and reverse packs. Unfortunately, to remove shaft, or check spool, tractor must be split. Picture will show pump, valve body with spool, shaft and linkage

 

[Tinkerer]

but would that cause the arm or valve controller to be locked in one position?

No, it will not.

 

[BILLYMAN62]

Thanks for that picture, it all is now clear to me what is taking place on the otherside of the bell housing. I will do the preasure check as sugested. But I whole heartedly think the issue now is that valve arm is lock up, maybe some rust from sitting so long. This picture opens my eyes now to a direction to proceed.

 

[Delmer]

You can see how much room there is for the valve spool to move, it won't go more than 1/2" or so, how far is your linkage moving? judge by the shaft in case there's play in the worn parts. on the bottom of that picture you see the inspection cover hole. on yours there is probably a structural brace that goes to the front bolster that requires a lot of larger bolts to be removed, but that's still relatively easy and straightforward. you can operate the machine without that brace in place, just don't do any heavy loading, or especially drive over rough ground that the axle reaches the stops. That access hole or the starter will let you see if the torque converter is moving on the flywheel, the pressure test will show that also obviously.

 

[sled dog]

Even before you check pressure, that shaft should have a grease zerk on the end. Grease it, disconnect the pedal linkage from it, then gently try to tap it back and forth. If you get it to move, you may have found your problem.

 

[BILLYMAN62]

so being able to see the insides, I felt safer using a little more hammer persuasion and I was able to free the arm so it now travels what appears to be the correct amount. I am now waiting for the battery to charge a bit and then give it a try. The picture was the key, knowing the hammer was working in the right fashion.

 

[sled dog]

Billyman, when you get it started, be in the seat and ready in case the spool is not in neutral. And be sure your trans is in neutral !!

 

[BILLYMAN62]

will do

 

[BILLYMAN62]

So here is the update. I was able to free the lever and am now able to drive forward and reverse. I did blow another hose, this time a steering hose, and have located a few more leaks on metal lines that are pitted to the point of now leaking. I will probably play hell finding replacements, the last metal line I replaced with rubber, and it seems to function. My outlook is now very good. Everything functions, there may be leaks, but from the field to my place and some help from friends, I have got it ready to now clean-up and know it's not a lost cause. Currently with all invested, I am into it for about 2100.00. I think I did all right.

 

[stinky64]

Good Dog

 

[sled dog]

Good Dog

'sanks !!!