NX55 HST Jerky Transmission at Low Speed
- Thread starter TN8Man
- Start date
seville009
Veteran Member
- Joined
- Oct 22, 2007
- Messages
- 1,511
Check the hydraulic fluid level
MinnesotaEric
Super Member
I have that issue and it goes away as the fluid heats up. Im thinking it is some
Pressure regulating issue—maybe even a dirty hydro filter (as my machine is very close to the servicing time of the hydraulics and transmission).
Pressure regulating issue—maybe even a dirty hydro filter (as my machine is very close to the servicing time of the hydraulics and transmission).
OP
TN8Man
Platinum Member
I agree it might be a hydro flow issue. I just changed both hydro filters about 30 hours ago so I think I'm good filter wise. I did notice a lag in pedal to movement where it seems I have to press the pedal further to get the tractor to move.
DieselBound
Elite Member
I'm sure you've already checked, but make sure you don't have any hydraulics dead-heading. Usually one can hear this happening.
- Joined
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- 2,098
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- Viburnum, MO
- Tractor
- Kubota BX2200, LS XG3135H, Grasshopper and Yazoo Zturns
Check for play in the linkage between petals and actual swash plate. On my LS the heim joints like to come loose.
dusty3030
Veteran Member
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- Jun 4, 2008
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- West TN
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- Kioti NX6010 Cab, Kioti RX7320 Powershuttle/ Cab, Kubota M7040 HDC, Kubota U35-4, John Deere 317G
Fly by wire, no linkage on OP's tractor.
My NX can be jerky as hell usually on medium range pedal to the floor and it's when the fluid has warmed up. I can set cruise and it stops and travels smoothly. I've figured out a bunch on my tractor but not this one yet.
OP
TN8Man
Platinum Member
I have also (in the past) experienced jerky response after several hours cutting grass on a hot day on my hilly property. When I got out of the cab I could feel the heat radiating from under the tractor. So this experience is possibly linked to hot fluid. After the tractor cools down some it runs fine. If I'm not running the PTO on hilly terrain it run's fine all day long. I changed the method I mow which seems to help. I now mow in low gear and the pattern is strictly straight up/down the hillside where I would mow horizontal before in medium gear.
The problem I have now is jerky movement while creeping forward in low gear with the PTO stump grinder running. This occurred on the first stump on flat ground so I don't think the fluid temp is a factor.
MinnesotaEric
Super Member
Cross posted from a different forum:
I also have a 2014, a very early NX6010 HST with a cab. My machine has 775ish hours and is approaching the 800 hour service. When cold it has frequently surged on the transmission but the issue immediately cleared itself up or I traveled slow enough so as to not trigger the issue until there was a tiny bit of heat in the trans/hydro oil at which point the issue always cleared itself up. This late summer, the issue became stupid. The HST surges in all ranges sometimes with the CEL flashing and sometime not until the trans/hydro oil is fully warmed up. It acts like the charging pump is trying to go out, but then works fine.
I brought the tractor back to my level 2 trauma center to lift my side by side that I need to weld on. Checking the hydro fluid when cold, the dipstick said it was low. But then fluid came pouring out moments later. The next day the dipstick again said low, but with the dipstick out, the build level came back up to full. I'm hoping my issue is something really stupid, so I popped off the trans breather (the candy cane looking thing to the left of the remote valve stack on the back of the tractor) and although it appeared to not be clogged, I blew out a big chunk of cogging whatever it was. I kind of doubt case vacuum or pressure is the cause, but malfunctioning breather can do all kinds of weird things in other transmissions. I haven't bothered firing up my tractor to see if clearing the breather helped or not as I'm waiting for my wireless microphone to charge up (YouTube stuff).
Since I'm orphaned without a dealer who knows about NX's, I put in a call to a long established dealer in TN to learn if there are any updates or software flashes I've missed out on as well as if updates can be applied by sending off the ECU rather than the entire tractor or if the mothership could add any color to our HST surging problem.
As I understand it the newer NXes had a battery ground strap between the trans hand the frame issue and there are two different transmission programs floating around.
EDIT: jumping the solenoid wise, be sure your midpoint PTO isn't on. It has happened to me twice. Also, I think your gear position switch is shorting out on itself.
I also have a 2014, a very early NX6010 HST with a cab. My machine has 775ish hours and is approaching the 800 hour service. When cold it has frequently surged on the transmission but the issue immediately cleared itself up or I traveled slow enough so as to not trigger the issue until there was a tiny bit of heat in the trans/hydro oil at which point the issue always cleared itself up. This late summer, the issue became stupid. The HST surges in all ranges sometimes with the CEL flashing and sometime not until the trans/hydro oil is fully warmed up. It acts like the charging pump is trying to go out, but then works fine.
I brought the tractor back to my level 2 trauma center to lift my side by side that I need to weld on. Checking the hydro fluid when cold, the dipstick said it was low. But then fluid came pouring out moments later. The next day the dipstick again said low, but with the dipstick out, the build level came back up to full. I'm hoping my issue is something really stupid, so I popped off the trans breather (the candy cane looking thing to the left of the remote valve stack on the back of the tractor) and although it appeared to not be clogged, I blew out a big chunk of cogging whatever it was. I kind of doubt case vacuum or pressure is the cause, but malfunctioning breather can do all kinds of weird things in other transmissions. I haven't bothered firing up my tractor to see if clearing the breather helped or not as I'm waiting for my wireless microphone to charge up (YouTube stuff).
Since I'm orphaned without a dealer who knows about NX's, I put in a call to a long established dealer in TN to learn if there are any updates or software flashes I've missed out on as well as if updates can be applied by sending off the ECU rather than the entire tractor or if the mothership could add any color to our HST surging problem.
As I understand it the newer NXes had a battery ground strap between the trans hand the frame issue and there are two different transmission programs floating around.
EDIT: jumping the solenoid wise, be sure your midpoint PTO isn't on. It has happened to me twice. Also, I think your gear position switch is shorting out on itself.