JD 310E backhoe. It started out moving intermittently. It may move 50 ft and stop. Then I would shift gears, move the reverser, or play anything else that had to do with moving it and it would sometimes start back again. Yesterday it would not move at all. It does not strain trying to move, it just act like it is not engaged. Even with the wheels in the air. Checked the 3 electrical plugs behind the fuel tank on the tranny and all are plugged in. ANY IDEAS, AND THANKS IN ADVANCE!
It's amazing the number of posts about transmission issues, that has to be the weakest part; after electrical and hydraulic problems. Fluid condition and quantity? Once you get past that, it's service manual time. There will be a diagnostic tree in there, easy, common things first, then checks that take more time and equipment like pressure gauges. If I didn't have the manual, first thing I would look at would be the linkages that control what the tranny is doing. If a pin falls out or shears, the linkage doesn't work anymore. If it's an electrical linkage, then you have to verify those bits are working. Not just having power to them, that they actually move whatever they need to move. $100 or so for a factory manual isn't that much when you need to fix a $20K machine. You'll save that much in time and grief if you have one.
ok......does the stop sign and park brake light come on on dash? could be park brake switch, mfgw fuse, brake relay, shifter handle on column, there is a diode behind guage panel and another that is tied in with 5 diodes under machine on left side frame beside the drive line area. could be the pressure switch on top of axle....when park brake is released this allows the trans to be engaged. will not send current to forward or reverse coil if this switch is bad. only one on axle, top/center. could be your seat switch. it is designed to cut out transmission and engage park brake if seat is not locked in forward position. the plug to this is back/left where seat mounts. this is what you do and test each time.....make sure seat is locked forward and plug is good, check 7.5 amp fuse, then swap relay with neutral start, then try tapping the park brake switch incase has a bad connection internally, if it isn't these you gotta get dirty to check the rest. you know what......i just remembered 1 more......sometimes the alternator will not excite until it is revved up over mid rpm's for a minute or so. it won't have enough voltage from battery to power all the above till alternator is charging good. i ran into that 1 time as well. the more i work on this particular machines problem i find something new that was causing it. 1 time just removing the fuses, relays and plug from park brake switch...1 at a time...and plugging them in fixed it. needed no parts. i wish you luck. i have tech manual and operation manual on this computer. will be back on it tomorrow. pm me your e-mail and i will send them to ya......not gona help with this though...doesn't give you any specifics on this system.
Good post J, It might also be low on trans fluid. Spring applied, hydraulic released..
Problem could be a faulty tranny disconnect switch on floor, loader control valve, or 4 speed shifter. I'd also be looking at the fwd/rev lever on the column. Looks like a pretty simple shifter looking at the parts diagram, only 4 wires. One would probably be 12V power supply, the other three; fwd, neutral, and rev. Should be pretty easy to check that out.