2014 Mahindra Max 28xl MB63 Backhoe Control Issue Fixed

[John Dougherty]

I don't know if this is the proper protocol for this thread as it covers a previous discussion about this same issue, but it might save some reading. My original issue with my BH was that it lost most of its' down force and on retraction the boom would slam back to the stowed position. Control was erratic at best. The clue to the solution should have been the slack that was present in the control lever. There was approximately 1/4" of travel with nothing taking place. Full disclosure: originally I thought that I could feel the spool when in the blind I put my finger into the positioner behind the hydraulic hoses and moved the control lever. I assumed that the positioner had blown its' guts out so I purchased a new one. As it turned out that was not the case. I did end up using the new one since the original had a bit of crap in it due to a missing protective cap. Would the old one have still worked? Probably, but I'm not returning the new one so...

The repair is pretty straight forward: Release any pressure on the implement and turn the engine off. Remove the two bolts that hold the metal shield covering the valve body, remove the metal cover. Loosen the the two hydraulic hoses directly in front of the positioner to be removed. Back out the positioner completely. If using the original positioner or a new one, put some locktite on the threads that extend from what looks like a bolt end at the top of the positioner. Hold down the control arm while threading the positioner back into the valve body. This took me three tries to get it started into the spool (round shaft being actuated by the control lever). These threads will make contact before the threads on the positioner body itself. The positioner will resemble a chainsaw sparkplug wrench w/o the screwdriver handle for the boom. Other positioners are shorter. Note that the control lever now has no slack when moved. This will tell you that you have successfully started the 'upper' threads into the spool. Re-attach the two hydraulic hoses and start the tractor to test the BH action. If good, then replace the metal cover over the valve body. I could not have done this w/o the help of Rob at Dave's Tractor. While this does not seem to be a wide spread problem in tractor nation the fact that it happened once indicates it could happen again. Hope this helps someone down the road.

 

[j wilson]

hi john...been kinda having the same issues with my backhoe...finally got the chance to play with the positioner valve on mine today, it took me a coulple tries to get it adjusted right,but it seems to have solved the issue of the boom slamming back, thank you very much for taking the time to explain your fix
j. wilson

 

[John Dougherty]

j wilson...glad it worked out for you. They always say to explain it like you're talking to a fifth grader, but I find them to be too smart for me. I have to paint by the numbers when it comes to such things. Do you find your boom being a little ahead of your dipper (the section that has the bucket connected to it) when you dig? Mine seems to lift a little prematurely as I draw back. This isn't a problem while digging a hole, but it is when trying to dress dirt on the level. This may be due to the shortness of the BH.

 

[j wilson]

john, i haven't had the chance to really play with it since i adjusted it, i'll have to pay attention to it next time i use it...thanks again!

 

[roughcut]

John, I just found this thread and I have the exact problem with my backhoe. I am not an expert at using it but man is it frustrating when it is so jerky and slams back. I don't plan on putting the backhoe on for a while but will definitely try this when I do. Thanks for sharing.

Dave

 

[John Dougherty]

John, I just found this thread and I have the exact problem with my backhoe. I am not an expert at using it but man is it frustrating when it is so jerky and slams back. I don't plan on putting the backhoe on for a while but will definitely try this when I do. Thanks for sharing.

Dave

Dave, glad I could help. Even though I did everything I said, I still have an issue with the control. Maybe there is an adjustment. I have to reach back from the seat and 'nudge' the lever back as it bleeds a little and I hear it. More of an inconvenience than anything else.

 

[John Dougherty]

I don't know if this is the proper protocol for this thread as it covers a previous discussion about this same issue, but it might save some reading. My original issue with my BH was that it lost most of its' down force and on retraction the boom would slam back to the stowed position. Control was erratic at best. The clue to the solution should have been the slack that was present in the control lever. There was approximately 1/4" of travel with nothing taking place. Full disclosure: originally I thought that I could feel the spool when in the blind I put my finger into the positioner behind the hydraulic hoses and moved the control lever. I assumed that the positioner had blown its' guts out so I purchased a new one. As it turned out that was not the case. I did end up using the new one since the original had a bit of crap in it due to a missing protective cap. Would the old one have still worked? Probably, but I'm not returning the new one so...

The repair is pretty straight forward: Release any pressure on the implement and turn the engine off. Remove the two bolts that hold the metal shield covering the valve body, remove the metal cover. Loosen the the two hydraulic hoses directly in front of the positioner to be removed. Back out the positioner completely. If using the original positioner or a new one, put some locktite on the threads that extend from what looks like a bolt end at the top of the positioner. Hold down the control arm while threading the positioner back into the valve body. This took me three tries to get it started into the spool (round shaft being actuated by the control lever). These threads will make contact before the threads on the positioner body itself. The positioner will resemble a chainsaw sparkplug wrench w/o the screwdriver handle for the boom. Other positioners are shorter. Note that the control lever now has no slack when moved. This will tell you that you have successfully started the 'upper' threads into the spool. Re-attach the two hydraulic hoses and start the tractor to test the BH action. If good, then replace the metal cover over the valve body. I could not have done this w/o the help of Rob at Dave's Tractor. While this does not seem to be a wide spread problem in tractor nation the fact that it happened once indicates it could happen again. Hope this helps someone down the road.

Update: January 2018
So my problem returned and I believe it was because I did a couple things incorrectly. The first is that I think the positioner backed out of the spool and the problem came back because I did the instillation as I described in the para above. Here's what worked: I left the hydraulic lines in place. I unbolted the valve body (three bolts) and unbolted the three bolts (each) connecting the levers to the turnbuckles. This allowed me to slip the valve body from underneath the guard. After that I used a broad blade screw driver (actually a ratchet w/ a blade insert wide enough to contact the slot in the bottom of the positioner) to tighten the slot at the bottom of the positioner to remove the slack between the spool and the positioner. Seem obvious? It wasn't to me. When the slack was removed from the control lever I reassembled the control mechanism and tested the dipper control. It worked as I had hoped and completed the reassembly. It is really important to keep the turnbuckles in their proper alignment otherwise the controls will balk/rub when you move the levers. To do this, capture the turnbuckles with a 7/16" or metric equivalent size when tightening the three topmost bolts securing the lever to the spools for fluent operation. As suggested, use some lock-tite to keep everything in place. I hope this solves your problem. I know this is not a big problem for too many people, but my tractor came with this problem and Mahindra was not equipped to solve it for some reason. If I can help you further, you can contact me at jdougherty1547@gmail.com. Hope this helps.