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JCB 505-22 Loadall 4 wheel steering won’t sync

ThatCoalGuy ยท 2014-02-13 10:39

I've never had problems getting the 4 wheel steering to sync before. It started when we had the below zero temperatures here. I naturally assumed the cold weather had something to do with it because it did sync up one day when it warmed up, but then happened again when it got down into the single digits. It got into the 30's yesterday but it still won't work. The proximity switch for the front axle lights up but the rear switch does not when I slide a metal putty knife under it with the selector switch it 2 wheel steer. This machine has the IP67 electrics. Has anyone had this problem before and/or have any idea where to start to troubleshoot what is wrong. Thanks

Replies11
  1. #1pajibson2014-02-19 12:08

    It sounds like the proximity switch or its wiring is bad I would follow the wiring harness from the switch all the way up to the brain box for the steering. Make sure nobody ran over a tree branch and rip out some wires. I have worked on a 506B with the IP67 electrics and I have some of the service literature for them. to include the tree branch scenario. If you want the service literature that I do have PM me your email and I'll send it to you.

  2. #2GregD12014-03-02 22:26

    It`s been a while, but let`s see what I remember. Do you mean it won`t go into 4 wheel steer or it won`t go to the desired steer function, either crab or cramp ? So rear switch won`t change ? Rear switch controls front and front switch controls rear wheels. Is the power light on in the proximity switch ? If you steer the wheels to match while it`s in 2 wheel steer, match them up to the axle that is out of whack, turn the mode swith to match the function the wheels are in. Go ubderneath and pass something over the prox switch and steer till the wheels are straight, then switch back to 2 wheel steer and see if it will function in other selected modes. Yes they are a PItheA, good luck.

  3. #3Contractor773792016-10-08 21:26

    Need Help same problem Can you send me the service literature. My 506b telehandler has the same steering issue. Rear and front wheels turned all the way to the left in crab mode. Steering wheel only moves wheels 2" and locks. Looks like they are functioning in opposite directions. Can you help?

  4. #4skata2016-10-11 00:39

    have you looked under the machine to inspect the proximity switches? there is one on each axle, above the steering bar that connects the two wheels together. the proximity switch senses metal...magnetic. i beleive they have a light on them too, to indicate they're working. if all your wheels are pointing left, and you're in four wheel steer mode, put switch in crab mode and safely get under machine and place a piece of metal over each sensor to trick the computer that the wheels are lined up. the wheels have to point straight before the computer allows you to switch steering modes, hence the proximity switches to make sure they're straight. in my case the steering bar would flex sometimes and take out the sensor. so i raised the sensor, and slid a spring (with a metal cap on the end) over the existing pin. that way no damage to the sensor if it happened to touch the pin, or spring in my case.

  5. #5jcb jeff2016-10-11 02:32

    Like Greg D1 said front control back and back switch controls the lock out function of steering if the the blue part of the switch is damaged i guess a new switch is in order the wiring used to get ripped out of the connection plugs from the switch on the axle to the main wiring harness check connection also place a metal object under the switch and see if it will work . You could swap the front switch for the rear to check that it is just a switch fault as this is easy to do and check you track rod for lift if required shim the up and down movement so as the pin does not damage the switch on axle.

  6. #6Contractor773792016-12-09 22:50

    Gentlemen, thanks for your input. It put me looking into the proximity sensors and wiring. I got my local JCB to check it out. They found a fuse had burned out. Located on row 2, spot 5. It controls the dash board. Replaced it and all works fine. They did say that I had high amperage load on the system that caused the fuse to blow. They said to clean up the remaining rough electrical connection to lower the amperage load. Thanks again gentlemen.

  7. #7JCB owner2020-04-30 17:39

    Do you still have the 506B service literature for the proximty sensors or fuses? i would like it very much if you could send me a copy.

  8. #8JCB owner2020-04-30 17:41

    My JCB 506B telehandler will not straighten out. stuck in crab mode. I want to know if there is a way to either check it out before calling for a repair or if anyone knows where you can get a manual to walk you thru the process.

  9. #9skata2020-04-30 18:20

    Have you physically checked the proximity sensors? There is one in front and one in rear. Above steering bar between wheels.

  10. #10JCB owner2020-05-01 10:54

    We have not, will check that out. Anything special I should look for?

  11. #11skata2020-05-01 16:57

    There's a welded pin on the track/steering bar on each axle, and when that lines up with the sensor, that's when the steering changes mode. Sometimes the steering bar flexes and can knock out the sensor. What I do is, raise the sensor and slip a spring over the pin, and place a metal cap on the end of it of some sort. Then the sensor picks up the metal cap on the end of the spring. And if they were to touch, the spring would just give way and not damage the sensor. Those are basic 3 wire proximity sensors i believe. You may be able to match up a generic one. Just match the voltage of the old one. Or go to dealer.