john deere 110 tlb no reverse

[Rsmtractor]

hi Guys, I have forward but no reverse in my hydrostatic 2007 yellow 110 tlb backhoe similar to the green john deere tractors(4120,4320,4500,4510,4520,4600,4610,4700,47104720. my fliud level is in the safe zone, metal screen and filters are clean,seat switches bypassed, pedal potentiometers are set to correct voltage. Replaced rear transmission ground speed sensor (has only one). Proportioning valves passed ohm and voltage check. Still no reverse. Could it be the valve portion itself.? any thoughts?

 

[Yanmar CC]

not sure if this would be related, but I had a Yanmar SC2450 that had the same issue. For that one it was a check valve inside the transmission. It was a known issue for them as the check valve had a bad run of parts. Wondering if you maybe have a gummed up check valve that is stuck open maybe?

 

[spitter]

Did you check the wiring harness going into the ECM? Some models had a speed sensor on the flywheel that have led to similar problems. Lots of good threads of people going through the same sort of trouble shooting, just have to do the search they will be very helpful. The only other thing I could think of is the transmission controller, but I have no idea how to check it out. Good luck.

 

[Hoss710]

have you checked your reverse coil? I have also seen the spool stick in the valve.