John Deere 6910 Autoquad gear change problem.

[Bill Turtle]

As per the title, when started from cold our 6910 often won’t shift up or down on the 1-4 shifts, causing the gearbox to be out of synch with the dash readout; which then flashes, and the tractor has to be switched off and restarted to allow any shifts to be attempted again.
If the tractor is allowed to warm up well then it changes gear ok and is then fine all day.
Does anyone know whether this could be down to weak solenoids on the side of the gearbox or oil (witham oils WBTO), or something else?

 

[Flat 10]

@Phil P @Tractortech

 

[Phil P]

Really you need to get the fault codes from the controller to help narrow down the issue. It could be a number of things, the 1-4 shifting uses a stepper motor on the side of the transmission to rotate the gear shift shaft. The fault could be anything from the shaft been stiff, the motor going weak, a fault in the motor driver, low voltage, a communication fault on the can system between the controller and the motor driver or the motor driver and the stepper motor.
Without any codes it’s a difficult one to diagnose.

 

[Bill Turtle]

Thanks @Phil P. I will try to have a look at error codes on Monday. To be honest I have owned this tractor for years, and it has been so reliable I had forgotten that it has a system for diagnostic codes. One of my favourite tractors, 50k as well!

 

[Chop]

As per the title, when started from cold our 6910 often won’t shift up or down on the 1-4 shifts, causing the gearbox to be out of synch with the dash readout; which then flashes, and the tractor has to be switched off and restarted to allow any shifts to be attempted again.
If the tractor is allowed to warm up well then it changes gear ok and is then fine all day.
Does anyone know whether this could be down to weak solenoids on the side of the gearbox or oil (witham oils WBTO), or something else?

Just wondering had u any look sorting auto quad on 6910 as I have the very same problem ?

 

[gpikcil]

What faults did you have?

 

[Red head]

I have same issue with my 6910

 

[Bill Turtle]

I have now fitted a new stepper motor on the side of the power quad box. The gears now change up and down ok. However, when I start the tractor the blue and orange warning lights take a little while to go out and the display takes a little while to show a gear. Ie 10 or so seconds. Does this mean I need to take the tractor to the dealer for some sort of calibration? Thanks for any guidance.