Hi all,
This is kind of long, but I tried to include a lot of detail I'm hoping there's a JLG wizard out there who can give me some pointers. Basically I need help figuring out how to get reverse working again, or how I can put this thing in "tow mode" so I can roll it back some and steer it in forward.
This is an old machine, and I can't find a lot more about it than the 3 manuals available at JLG.
I've had it less than a week and bought from a local individual, who bought from another local individual, who bought from an electrical contractor several years ago. It has about 4300 hours.
Current issue I am trying to resolve is the reverse drive. When I took delivery, it would run in reverse, but was very sluggish. I drove it around and cycled everything, and when I ran it 2 days later, no reverse.
Right now I have driven it into a spot where I can't steer into a turn (edge of driveway and a steep grade). I tried flipping the hubs to disengage the drives, but I think the brakes are staying on, so I couldn't tow it. I tried running the controls to release the brakes at the same time and still couldn't tow it (maybe because it is 18,000 lbs).
Things I've done so far:
-swapped PQ controllers (Swing and drive) both work in the other spot identically.
-verified 12v from the basket controller to the solenoid (PQ controller to reverse, 12v at solenoid wire)
-measured solenoid coil (6 or 17 or so ohms, I can't remember, but was almost identical to the 2 solenoids next to it that function ok)
-pulled solenoid, bench tested with 12v good (takes 1/2 a second and armature full extends)
-pulled valve cover off, looked at proportional valve while oil ran out. The engine and pump were off, so I'm not certain if those bits are working right
-disconnected valve outlet and cycled reverse prop control. When I did this it didn't seem to change the oil flow coming out, which was just kind of a dribble. I did this in several stages because I expected it to blast out of there, but it just slowly oozed out.
-this leads me to believe it is the spool or whatever you call the bits in the valve.
Other details on the machine:
Mine was "installed" in 1986 based on the inspection date stamped on the machine.
It has these variants of components:
-Wisconsin dual fuel engine (although it looks like some of the propane bits are missing on the intake).
-3 stick proportional controls, no steering wheel, Vickers Proportional valves (I think) with original square solenoids that are obsolete. The Lift prop control was replaces with a toggle, and there is some hack job wiring to accomplish that in the control box
-Racine Bang-Bang valves (I think)
Other things inoperable:
-aux hydraulic
-2 speed drive maybe
-high speed drive maybe
-engine high/low (it runs the same rev all the time)
-swing prop control (replaced with 3 position toggle)
-busted basket rotate hoses
This is kind of long, but I tried to include a lot of detail I'm hoping there's a JLG wizard out there who can give me some pointers. Basically I need help figuring out how to get reverse working again, or how I can put this thing in "tow mode" so I can roll it back some and steer it in forward.
This is an old machine, and I can't find a lot more about it than the 3 manuals available at JLG.
I've had it less than a week and bought from a local individual, who bought from another local individual, who bought from an electrical contractor several years ago. It has about 4300 hours.
Current issue I am trying to resolve is the reverse drive. When I took delivery, it would run in reverse, but was very sluggish. I drove it around and cycled everything, and when I ran it 2 days later, no reverse.
Right now I have driven it into a spot where I can't steer into a turn (edge of driveway and a steep grade). I tried flipping the hubs to disengage the drives, but I think the brakes are staying on, so I couldn't tow it. I tried running the controls to release the brakes at the same time and still couldn't tow it (maybe because it is 18,000 lbs).
Things I've done so far:
-swapped PQ controllers (Swing and drive) both work in the other spot identically.
-verified 12v from the basket controller to the solenoid (PQ controller to reverse, 12v at solenoid wire)
-measured solenoid coil (6 or 17 or so ohms, I can't remember, but was almost identical to the 2 solenoids next to it that function ok)
-pulled solenoid, bench tested with 12v good (takes 1/2 a second and armature full extends)
-pulled valve cover off, looked at proportional valve while oil ran out. The engine and pump were off, so I'm not certain if those bits are working right
-disconnected valve outlet and cycled reverse prop control. When I did this it didn't seem to change the oil flow coming out, which was just kind of a dribble. I did this in several stages because I expected it to blast out of there, but it just slowly oozed out.
-this leads me to believe it is the spool or whatever you call the bits in the valve.
Other details on the machine:
Mine was "installed" in 1986 based on the inspection date stamped on the machine.
It has these variants of components:
-Wisconsin dual fuel engine (although it looks like some of the propane bits are missing on the intake).
-3 stick proportional controls, no steering wheel, Vickers Proportional valves (I think) with original square solenoids that are obsolete. The Lift prop control was replaces with a toggle, and there is some hack job wiring to accomplish that in the control box
-Racine Bang-Bang valves (I think)
Other things inoperable:
-aux hydraulic
-2 speed drive maybe
-high speed drive maybe
-engine high/low (it runs the same rev all the time)
-swing prop control (replaced with 3 position toggle)
-busted basket rotate hoses
