| Author | Message | ||
     Griffmeister |
Well, you've seen just about everything there is to see posted on the Quick Board so I thought I'd try. Working on a 650H with some drive issues, sometimes won't move and occasional mistrack, basically goes into hard right on forward only. Had two codes in TCU, F363 and F3M1. Well the F363 was easy, no engine rpm reading on the TCU display.Checked wiring and then replaced the pump speed sensor. The F3M1 code is a little harder to solve. Normally that would be the left motor speed sensor but you can read motor rpm perfectly well in the TCU display. When I pulled the rear cover I could see that the left motor two speed solenoid was puking oil. Figuring maybe oil could also be leaking internally causing the motor to shift speeds unexpectedly I went ahead and put a seal kit on the solenoid. After this, ran the machine to warm the oil then did a full transmission calibration. Went through a complete cal with no problems. Took the machine out back and checked operation, pushed some dirt, everything was great. Brought it back to the truck to put the covers back on when suddenly it goes into a hard right turn. Back up it twitches left then goes straight. Go forward and hard right again. If I watch the TCU display while it's turning, I can see that the steering input is for straight travel yet the left motor rpm reads way higher than the right motor and what's really strange is the left pump PMP amps are also higher than the right pump which I thought would indicate a commanded turn but I'm not sure on that one. So how about it, anyone got any ideas? | ||
| Ducbsa |
77 connector?  | ||
| Oldog |
Griff not a dozer tech but fair at trouble shooting systems. From your post Took the machine out back and checked operation, pushed some dirt, everything was great. Brought it back to the truck to put the covers back on when suddenly it goes into a hard right turn. Back up it twitches left then goes straight. Go forward and hard right again. What hydraulically controls each drive? a valve or some adjustment to the pumps? can you verify the command signals independent of the "TCU" ( transmission control unit ?) What do the PMP amps refer to, is this a feed back from each sides main pump to show the TCU the pump output? Can you post a sketch or block diagram of the electrical system for steering? can you monitor say with a laptop all signals into and out of the controller at the same time? It looks like all of the signals may be right, after loading some thing drops off Confirm its not electrical. cracked circuit boards, and chafed wires. If all the signals are in expected ranges and the machine is not operating normally then the command actuator what ever it is needs to be checked. (variable valve or pump, that I am no help with) My only claim to any know how was making a drive by wire system or a piece of equipment my employer builds, called a transfer deck. I used an Allen Bradley SLC500 PLC to operate the hydraulic proportional valves, user inputs were via Hall effect Joysticks. The sticks controlled direction and speed of the platform and of 2 winches each with 59,000 lbs of draw bar force. The client loads and unloads rail road ties into and out of processing and storage equipment. Total length of the machine is about 180 feet, fully loaded weight is 3/4 of a million pounds. } | ||
| Two_seasons |
Any time you do a hydraulic oil service, whatever that may be, you need to drive out the air in the system. Cavitation in the system will allow goofy things to happen. Many cycles of forward, reverse, partial, full travel need to be done to ensure positive and sure fluid changes to the motors. Also, look for linkage issues. Loose set screws, sloppy linkage. Edit... You may also have a loose fitting, allowing air to enter the pumps/motors. (Message edited by two_seasons on May 12, 2013) | ||
| Griffmeister |
Thanks for the input Oldog, sounds like your system was a ground up design, and it could all fit inside a shoebox.  Yeah, this is basically a closed loop hydrostatic drive, two variable displacement piston pumps coupled to two variable displacement piston motors. The motors are only high or low thus the two speed solenoid and each has a speed sensor. The pumps are infinitely variable each with it's own PCP controller and one speed sensor for antistall. The TCU is in charge of all this getting input commands from a joystick with two rotary sensors for forward/reverse and left/right and two more for throttle input and decel pedal. The TCU is pretty much a sealed proprietary unit (no user servicable parts). My problem is that it decided to play bad boy at the end of the day when I was packing up to leave. We have a proprietary software program called Service Advisor which I'm going to have to dig into, just didn't have the time yet. Was hoping on the outside chance that someone had been in this situation before. Have rarely had a J pattern mistrack on this type of machine so it was kind of like a new experience. That's where I need to find out what PMP amps actually are. I thought it was a commanded value but I better be sure. Thanks again. | ||
| Mr_grumpy |
You need to PM Alex Prior, he works for Deere. | ||
| Oldog |
Your welcome I had hoped that it might help. The design was some thing that was in my mind for years Earlier and smaller versions of the deck were almost totally manual. The cabinet, control station and panel board are all a freestanding pedistal about 30" tall 36" wide, and depending where measured 12 -18 deep  I operate and display equipment not on the platform by wireless. Although I doubt my panel would stand life on a dozer.... As Grump Prior is an engineer with JD. |
