Hello new member here. Going by the handle farmer Steve. All our equipment is John Deere. I just love John Deere if they made a half ton or a barbecue I would want one. We have a John Deere 744E and we got it used last year however the transmission cuts out in all gears. As long as you go easy on the throttle you can push real nice but as soon as you put your foot into it the machine just stops moving and builds heat according to the Transmission temperature gauge. It’s like a bypass valve is set to low and as the pressure builds it just all of a sudden dumps. We changed the transmission oil with new but didn’t see any issues. Anyone have some thoughts. Thanks Steve
Welcome to HEF Steve ! Please post a machine serial number. Was the filter cut open and inspected? Any warning lights come on on the dash? The clutch cutout switch on the side panel is in the off position? This usually points to a transmission main pressure issue. Has the main system pressure been checked?
Thanks for your response. Please see attached serial number of both the machine and the transmission.
In regards to the filter no it has not been inspected. I was previously advised from a neighbor that there is no filter. However after taking a closer look today there is a canister type filter on the side of the frame next to the transmission. The hydraulic lines loop around and it appears to go to the transmission. No warnings come on in the cab and the clutch cutout switch is off. I will say that someone else has been messing with the wires and there are a lot of wire splices in the cab so I would not be 100% trusting that everything works correctly. It does shift forward reverse and all gear ranges fine. Perhaps the cut out switch could be unplugged at the transmission if it is a potential cause of the problem.
No the main system pressure has not been checked. I would need some guidance to do this.
You need to acquire the tech manual TM1454. The clutch cutoff would have to be disconnected hydraulically to rule it out. First, remove that filter and inspect for debris. If clean, then let's rule out the clutch cutoff circuit and perform a main system pressure test. Check your PM.
Good Evening. Following your advice. There are no issues with the filtration canister. The oil was clean smelled fine and no dirt or debris, filter was also clean. (Reassembled) See photos below the lines run to the valve bank and solenoids for the mentioned clutch cutoff. The second photo shows that the red and green wires are not connected. Only the black one not sure what that does. I do not mean to jump ahead of the process but I noticed in the notes that there is a pressure regulator valve below the cut out valve. This is of interest to me. That is probably why we have to check the system pressure next. LOL
Yes, disconnect the line and cap the port on the valve you are pointing to. See if the trans works any better. That is the park brake pressure switch. Does the park brake light work?