Tractor Repair: Case IH stuck in 4 wheel drive, electric solenoid, solenoid valve

Question
My tractor is stuck in 4 wheel drive. There is a 12 volt signal going to the solinoid at the transfer box. I do not know if the solinoid need to be energised or not to disengage. I have tried a straight feed from the battery but nothing seems to happen. Is the stud that the solinoid sits on supposed to move in & out, I was to wary to force it.

Answer
Hello,

  You didn't say what model this tractor is, but in my experience, any Case IH tractor that has an electric solenoid for the 4 wheel drive has a clutch that is spring applied and pressure released.  This means that when the solenoid is energised, 4 wheel drive is off, and when the solenoid is not energised, 4 wheel drive is on.  The solenoid operates a valve that turns on the oil pressure to the piston in the clutch, and pushes it to the disengaged position.  When the power to the solenoid is shut off, the oil is released and the springs apply the clutch to engage 4 wheel drive.  The stud that the coil sits on does not move, but if you unscrew it out of the tractor, there is an internal spool that moves in and out from magnetism of the coil.  When 12 volts is applied to the coil, you should hear a slight click as the spool moves.  You can also check for magnetism by putting a wrench over the end of the stud and seeing if it is pulled onto the stud. It's possible that the coil is bad or the spool is stuck open.  Don't forget that the coil also needs a good ground (earth in the UK) besides 12 volt power.  Continuity through the coil can be checked with a multimeter.  There should be 10 to 20 ohms resistance through the coil.  There also has to be about 300 psi regulated circuit hydraulic pressure available to the solenoid valve for it to be able to release the clutch.  If everything checks out OK, then the 4 wheel drive clutch needs repair.