BX24 (50 Series) 4WD Shifting Question (Slips in to 4x4)

[Forcus]

Hello, searched but didn't find anything so posting.

We have a BX24 with 550 hours we purchased with 400 hours 4 or 5 years ago. We think it may have seen some abuse even with the low hours.

Since I've had it, it has occasionally slipped from 2WD to 4WD on its own and it has been getting worse. My original concern was damaging something by having it in 4WD and not intending it to be, making a tight turn, etc. Now I am more concerned about damaging the transmission and having an expensive rebuild.

Doing some light reading it appears there can be internal and external problems. For external the lever can be misadjusted or bent and rubbing on something and could cause it to pop in or out of 4x4. I checked - no issues here. Moving the lever with the machine off it feels like there is no or little detent keeping it in place. Checking the Messicks diagrams (https://www.messicks.com/ku/84755?sectionId=216444&diagramId=335102) it appears there is an externally removable bolt with a removable spring and dent ball. I am hoping against hope that it is just a spring that has lost its ability to resist compression but what I am concerned about here is that if I remove the bolt and spring, will the detent ball drop in to the transmission case? I have an extensive history of screwing myself over with these kinds of things and could totally see the ball dropping in to the case if I remove the spring that is pushing the ball against the 4x4 lever..

Thoughts? I had resigned myself to having a transmission rebuild / refresh by the dealer for $2-3k but if I can replace a $5 spring instead...

 

[whitetiger]

Hello, searched but didn't find anything so posting.

We have a BX24 with 550 hours we purchased with 400 hours 4 or 5 years ago. We think it may have seen some abuse even with the low hours.

Since I've had it, it has occasionally slipped from 2WD to 4WD on its own and it has been getting worse. My original concern was damaging something by having it in 4WD and not intending it to be, making a tight turn, etc. Now I am more concerned about damaging the transmission and having an expensive rebuild.

Doing some light reading it appears there can be internal and external problems. For external the lever can be misadjusted or bent and rubbing on something and could cause it to pop in or out of 4x4. I checked - no issues here. Moving the lever with the machine off it feels like there is no or little detent keeping it in place. Checking the Messicks diagrams (https://www.messicks.com/ku/84755?sectionId=216444&diagramId=335102) it appears there is an externally removable bolt with a removable spring and dent ball. I am hoping against hope that it is just a spring that has lost its ability to resist compression but what I am concerned about here is that if I remove the bolt and spring, will the detent ball drop in to the transmission case? I have an extensive history of screwing myself over with these kinds of things and could totally see the ball dropping in to the case if I remove the spring that is pushing the ball against the 4x4 lever..

Thoughts? I had resigned myself to having a transmission rebuild / refresh by the dealer for $2-3k but if I can replace a $5 spring instead...

As long as the roll pin is through the lever and shift arm, the ball can not fall into the case.
If you were to remove the roll pin and let the arm move into the case just a little, the ball could fall inside.

 

[Forcus]

As long as the roll pin is through the lever and shift arm, the ball can not fall into the case.
If you were to remove the roll pin and let the arm move into the case just a little, the ball could fall inside.

Thanks for the reply, yes the roll pin and lever are secure, nothing appears to have moved although I will double check. I was afraid that the fit was such that the ball might fall in to the case if the pressure from the spring was lost. I will try to rig up something to pull the shift arm towards the outside of the tractor to give me as much chance as possible to not have the ball fall in the case. I'm a little nervous as technically I could just have a strap or something on the 4WD lever to keep it from slipping it in to 2WD but I hate hack fixes, especially on a machine that has retained its value.

 

[whitetiger]

Thanks for the reply, yes the roll pin and lever are secure, nothing appears to have moved although I will double check. I was afraid that the fit was such that the ball might fall in to the case if the pressure from the spring was lost. I will try to rig up something to pull the shift arm towards the outside of the tractor to give me as much chance as possible to not have the ball fall in the case. I'm a little nervous as technically I could just have a strap or something on the 4WD lever to keep it from slipping it in to 2WD but I hate hack fixes, especially on a machine that has retained its value.

No need to rig something to pull the arm over, the ball can not fall into the case as long as the roll pin is in place.

 

[Forcus]

Thank you again for the help! Finally pulled the bolt and no spring or ball.... So I added a spring and ball and now it works! But of course I question what has been done to this poor transmission.. probably have to find a good place to send it off to go through it next winter.