JD6410 remains in FWD

[sablerock]

Guys
I understand the MFWD solenoid needs permanent power to keep it out of FWD.
I have tested the solenoid,it generates magnetic field.
I have removed the valve assembly, that also works fine with solenoid attached.
But, the tractor remains in FWD.
What can be the problem?
Albert

 

[Agvg]

Brake light works?

 

[Zebrafive]

Since you have been having electrical problems make sure you have full voltage to solenoid.
If that's OK, you could have low hydraulic system pressure, failing to disengage the front wheel drive. It should be 170psi Check for pressure in and out of FWD. None for in, 170psi for out.
If you have correct system pressure from the transmission, but not at the FWD valve, Sealing rings on the clutch piston might be leaking. Belleville springs engage the clutch, hydraulic pressure on the piston disengage the clutch

 

[sablerock]

Since this tractor were in electrical fire, no break lights wiring.
FWD is engaged/disengaged with ON-OFF rocker switch , which powers FWD solenoid .
Voltage on FWD solenoid is good, 11-12V.
Not sure where to check pressure. Attached guage to part-no RE212878 press switch hole.
Constant reading of 16 Bar(227Psi ?), with solenoid on and off and thru all gears.
How do I test pressure at the FWD valve?

 

[Zebrafive]

To check transmission system pressure, there should be a port marked SYSTEM. There is also a SYSTEM port on the Priority valve at the rear of the tractor. There are three ports, two on the top and one at the bottom. Bottom one is system pressure. The top two are load sense and steering pressure.

For the MFWD (mechanical front wheel drive, so not to confuse FWD with forward), test port is at the bottom by the solenoid, key 12 in the drawing. You must have pressure to disengage MFWD (170psi for USA tractors)

 

[sablerock]

Again many thanks.
Will leave transmission for now since now problems there.
Found key 12: L41709 PIPE PLUG.
Hex bolt that sits above the draw bar next to solenoid.
Just some planning:
Is there a deluge of oil going to flow out?

 

[Zebrafive]

Again many thanks.
Will leave transmission for now since now problems there.
Found key 12: L41709 PIPE PLUG.
Hex bolt that sits above the draw bar next to solenoid.
Just some planning:
Is there a deluge of oil going to flow out?

That's the plug. Never worked on one, so no idea how much oil you will lose.

 

[sablerock]

since the drain plug is adjacent I think it save to first drain the oil.
Anyway, that bolt thread spec is M14 x 1.5mm, so I first have to make an adapter for my gauge.
Will let you know what happened.

 

[Zebrafive]

Since this plug is on a passage, not the sump, you may not get much oil???
Wise to figure out what adapter you need first.
Did you find the "system" port on the rear priority valve?

 

[sablerock]

Ok, my friend from USA.
4x4 is now working!
Adaptor and gauge gave reading of 0 bar.
Toggled rocker switch and reading remained 0 bar.
Checked reading at solenoid and 0 volt.
Pulled toggle switch out and fiddled wires, intermittent 12v output.
So, replaced it with new rocker switch and voila 10bar(145psi), and tractor popped out of MFWD!
Many thanks again.
Found Priority valve, pls check my photo for correctness.
What should the pressure be at each port.?
Also, on the front cover on transm are switches for LOW OIL PRESS, LOW OIL TEMP.
What are these trigger values?
What should the operating temp and pressure be?

May I pls know your name?
Albert