I've got a D4G XL ( mhk16840 ) that will only turn left when I release the parking brake. Joystick has no effect on movement. No fault codes on the computer. Left track is not locked up it just moves a lot slower than the right. I've recently replaced the joystick and parking brake switch and speed sensors on both sides. It's been working fine. Any ideas on where to start troubleshooting? Harold
Have you removed the magnetic oil drain plug on the LH final drive to take a look for nasty sparklies in the oil or on the magnet.?
No. I looked for contamination everywhere else but forgot the final drive. I'll check it next. Thanks.
Pretty sure you have to calibrate those speed sensors after replacement.
BTW the MHK16840 number you quoted above is the Engine S/N. The tractor S/N is HYD02193. Just a thought. How did you determine that there were no fault codes on the computer..?
d9gdon - I replaced the speed sensors in the field 3 or 4 months ago. I don't have ET and the machine tracked straight and worked great so I just kept working. Would that cause a problem to pop up later like this? Nige - Thanks for the clarification. I jumpered the code plug and it read 2 2 2. I thought that meant no active or stored codes right?
Sorry, I wasn't trying to trick you or anything like that. Most people have absolutely no idea how to jumper the Code Plug to show the Diagnostic Codes. I was simply curious. Off on a different tack. Why did you replace the speed sensors a few months ago..? Also when the current issue started, was it sudden or did the machine start getting worse over time until it got to the state it is now.? Lastly have you changed the hydraulic filter recently and cut open the old one to have a look in the media for any nasty sparklies in it..? Let me also get this clear. The joystick has absolutely no effect on the machine steering, so you can't deliberately turn either left or right with it..? The bad news is that to calibrate the joystick left-right signals requires Cat ET, as does the F-N-R position sensor in the joystick. If a joystick has been replaced both calibrations are required.
I learned how to check the codes from one of your posts, thanks for that by the way. The machine slowed down to a crawl and diagnostic code pointed to the right speed sensor. Both sensors were original so I replaced them both with the new upgraded sensors. Handled and tracked like new after that. The issue was sudden. I was working and everything seemed fine, shut it off for a break and would only turn circles when I fired it back up. New hydraulic filter and I checked for contamination and it was clean. The joystick has no effect on movement. Reverse turns on the beeper that's it. I initially thought maybe the control valve on the left motor was stuck from contamination, but I would think that the joystick should still have some effect on movement.
Was the joystick replaced at the same time as the speed sensors? I don't know why it would work perfectly if everything was replaced at the same time, other than there is a computer involved. Maybe you recently lost battery power and when it rebooted it lost calibration? It's going to take someone with ET to calibrate anyway. Takes a couple of hours at the most. While they're doing it, get them to set your speeds like you want. Mine came with reverse speed ratio that was double forward speed, which was terrible for pushing brush. They can set the ratios the same or change the top speeds, etc.
The joystick was replaced more recently. I've got a guy going to check it out with ET. I plan to tear a little deeper into it tomorrow. I'll let you guys know what I find.