I have a Deere 310sg (T0310SG945417) it wont move in reverse. back up alarm comes on and when you spike the throttle it trys to roll forward. Just installed new fwd/rev/neutral valve body with solenoids and harness still does the same thing. i tested the harness and the solenoids are getting power. could the timer relay behind the dash cause this?
Welcome to HEF Mason ! Thanks for posting a serial number. It moves forward OK (except 4th)? Oil level good? Timer relay would kill all movement, not just select gears. It is a powershift trans and not a syncroshuttle, correct? Did you check the FNR out for issues? Down near the hydraulic filter is a bunch of diodes for the transmission circuit. Check them as well. Also look for wires that may have pulled out of the diodes (pull on them to see if any pull out). You handy with a meter? Remove the transmission (FNR) fuse and place an amp meter in its place. With seat forward and park brake released record the amps for each gear forward and reverse and post.
Well I have the transmission out right now and I’ve had it apart and cannot seem to find anything out of Tolerance. Is there anything else I should check over before I put it back in?also I did check the fnr and it seems to be working. As for the Diodes I will have to check them when I get the trans back in.
Are these the diodes?
What is this?
Yes. Concentrate on the ones with blue wires. They would be for the transmission. What are the wire numbers attached to it and their color?
How did the pickup screen look in the trans? How many hours on machine? Did you happen to measure clutch pack clearance when you had it apart?
I didn’t measure clutch clearance. I was just checking to make sure all the snap rings were in place. The pick up screen and Filters had no debris. Fluid was very clean as well. It has 6400hrs
I checked to make sure all the diode wires were intact and they were. the numbers to the plug are X41 yellow and R20A black. whatever is at the end of the plug looks rusty. is it possible that one of the diodes are bad?
That should just be a plug (or possibly a resistor, I don't remember). Either way ignore it. Yellow wires are not used for any transmission circuitry. Those wires are for a hydraulic temperature sensor which was not used on your serial number.
Should I replace all the diodes?
If they tested good then no.
So all the old diodes tested good, I replaced them any way. While I was looking around under the machine i also checked for pinch point on all the transmission wiring and couldn't find any problems. Do you know of anything else I should check before I put the transmission back in the machine?
Not at the moment. There should have been thorough testing "before" the transmission was removed to determine the cause. Was the presence of voltage checked to all the solenoids to determine if the issue was a power supply? Amps for the transmission solenoids checked (measured at the fuse)? Were pressures checked? Filter cut open and inspected? Clearances could have been good but your piston seals could be wiped. Pressure checks could have confirmed this. "Seems" to be working. Just because your back up alarm came on don't rule out the FNR. Again thorough testing with a meter to determine if it is functional (while plugged in and connected to the transmission and back-probing).