Hi hoping someone can help me out a lil, I picked up a 550 load all and I had no idea of the history all I know is that they were using it for parts for some of their other machines so I had some broken parts thrown in with it When I got it the right front hub was broken at the track bar that keeps both front wheels turning the same direction, rear drive shaft was missing, steering shaft and wheel was torn apart and broken one laying in the cab on the floor. It's missing some various sensors and other stuff like that. I have replaced the right hub and steering wheel shaft, since then and gotten it running. The boom functions as it should but the steering won't work I suspect the steering unit is the problem. It has 5 hoses going in and out of it, I can unhook both left and right and return line outputs only leaving pump pressure going in and the pressure return going back to the pump hooked up. if you turn the steering wheel to the left it's sorta hard to turn and nothing really happens and not much oil comes out of the open hose when you turn to the right it feels like it hits a stop, and some really foamy looking oil comes from the right port and both the oil supply line from the pump and the pressure sensing line going back to the pump get rock hard when your turning the wheel in a right direction and hit that hard spot almost seems like it wants to burst those 2 hoses and all of the other 3 hoses combines don't hardly dump enough oil to even fill a beer can when running it for over a min or so. I assume with nothing hooked up going out of the steering unit and only having pump pressure going in and out there is NOTHING electronic that could even be causing this problem, I should get a steady stream of oil from the right and left when putting those inputs in the steering wheel correct? Also one time when messing with it after I got the hub on I was able to move it forward and backwards under it's own power unable to steer at all, the trans oil pressure light has been on and now I get nothing from the transmission not even a hint of movement from the output shaft on the trans when you put it in either forward or reverse and it is full of fluid not sure how it could move one time no problem than not the next. Backup beeper and all that works so I assume it's getting all the signals to the trans and it looks like there isn't much in the line of electronics that controls the fluid pressure from the torque converter, wondering if there is a sort of charge pump on the trans for the converter if it is built into the converter and that is where my problem is, but I sorta of rule out electrical once again since I have the trans fluid pressure light on. I have no clue as to what was broken or how, the spindle looks like it was removed maybe off another machine and the steering shaft was for sure taken from it for a diffrent machine. The steering unit looks like it hadn't been removed just by how the hoses were still hooked up but I don't know that forsure, they were using this unit as a parts machine for their other 2 running units. I recall them having transmission problems with one of the units not sure if this was the one and they robbed steering parts off it or if the steering broke on this unit and then sitting for a couple years and pulling parts off it caused the trans problem and steering unit problems. One of the joys of getting the machine as a basket case and not having a single clue as to the history or events of stuff that happened to it. I have alot of $ tied up in this machine and now the steering unit and trans are costly items just wondering if anyone can tell me from what I describe if I am on the right course of action or if I am missing something simple, I know the steering and transmission are both on their own pumps and steering is on with the loader functions and it has pressure for sure. Any help would be great Thanks SO much for your time.
Hi Im on the other side of the pond how old is it (got s/no of machine) but i guess this loadall has the engine mounted on the side and not under the boom.so the hydraulic pump would be stuck onto the back of the main hyd pump unit from the bevel drive box and is the smaller pump and there is a priority valve on the chassis which gives priority to steering over radiator fan . Transmission will require a pressure gauge putting on the main test port to check mainline pressure approx 9.7 - 12.8 bar at 1000 rpm at 50 degree. gearbox charge pump is inside the bell housing and torque converter ,there is a pressure maintenance vale on the gearbox could be stuck.If you could post some pics and serial and info i may be able to help a bit more.
Thanks JCB Jeff my serial # is 077 2405 and it's a 1998 model year it has the engine on the side not under the boom. I have read about other people having problems with the no right turn and really not much happens when it's turned to the left and they had electrical problems, thus I unhooked the hoses from the steering unit and it still seems to do the same thing. One of my next plans was to really try to trace the lines and maybe disconnect the part for the level adjust ram and hook that to the steering valve and see if I can make the wheels turn vial that toggle switch. The ports I have coming out of the steering unit are L R T P and also one coming out of the side of the steering unit running back to the pump along with the P line With the hoses disconnected from L R and T all at the same time if you run the machine nothing comes out of any of the 3 open ports if you turn the steering wheel to the left not much happens a small trickle of oil from the L and R ports, if you turn it to the right it hits the hard spot right away and stops, you can have the machine full RPM and really crank on the steering wheel past the hard spot but both lines the P and the one off the side of the steering unit get rather hard to the point where they look/feel as if one might burst when doing this you get some REALLY foamy oil out of the R port but not very much and it looks as if it's been pushed through a pinhole from the amount of air mixed with it. As for the trans I figured I would drain the oil replace the filter and do you know if it has a sump screen ? Once I have done all that and if I still get nothing I will borrow a set of gauges and check pressures, Do I need to get JCB oil for the trans or is there any thing else I can use? I will post some pics of the gearbox and hyd pump and steering unit when I get a chance I just wanted to make sure there wasn't something simple I was missing that will deactivate the trans odd part is it went forward reverse no problems one of the times I was messing with it of course it had been sitting for a long time and the low fluid pressure light was on then I think as well after one of the many starts and stops of the engine messing with the steering issue I lost all transmission movement so hopefully it's just a bunch of crud stuck to the sump screen or something like that.
check the priority valve on hyd pump either on the end of the pump or stuck on the side of the pump make sure spool move free as this is sensed from the orbital unit on steering wheel . i guess you have all the steering modes working on the dash and the switch is working as this has a solenoid bank and spools to control. transmission oil should be automatic trans fluid in that serial no ,the strainer is a plate on the bottom/side of the gearbox which is almost like a lemon shape with two 13 mm headed bolts pull bolts out have a drain tray to catch 4 gallon or so handy and check screen should be clean you might need a new cork gasket .you will need about 23 liters to refill trans .the transmission is a powershift it possibly have a ecu under the seat base or on top of the transmission we used to get problems with the ecus or some times it can be the micro relays at fault in the end of the dash when you open the door under the panel .other trans issues are the forward reverse stalk on the coloum micro switch faults or you might have a trans dump switch button fault on the loader lift levers or the wires chaffed and shorted to earth so as the trans goes into N so as to operate the loader at high revs with no travel try moving the levers with it drive and see if it moves .
It's been a while I stopped working on it because I got frustrated with the loadall and have had other projects so I just had sorta forgotten about it till the other day. I went to pull the steering unit off was going to send it in and have it tested. I fixed the steering issue long story short someone had switched the location of the pump pressure input line. I discovered this by removing lines one by one and each time seeing if the wheel would turn right it wouldn't till I removed the pressure line from the pump then oil shot out of that location when manually turning the wheel with no engine running or oil pressure to it. I put the hoses where I thought they should go and it works just fine. Now for the trans, I have drained the ATF out of it it looked rather brown and smells burnt, the spin on filter didn't look to have any build up of anything inside when I cut it open and the suction screen on the trans wasn't clogged at all but there was a very small amount of what looked like aluminum chips at the very base of the strainer maybe about 10-15 nothing bigger then the size of coffee grounds but they looked like nice shinny aluminum which worries me because I would assume if that's the case they came from inside the converter which sorta explains the no movement. My thoughts are to put in new fluid and filters see what happens, maybe even try pushing it around with it running in gear with some engine RPM in case somehow there is air in it. The trans pressure light is on all the time, and goes off if you unplug it, not sure if it would be on if the ECU was commanding the trans to dump pressure. The one odd thing is that below freezing here and after letting the machine run for an hour or more it did get the trans warm enough to start melting ice and snow off it and the fluid was nice and warm so that tells me that it is circulating through out the system. I have tried EVERY combination of switches on or off and moving every lever through out the entire RPM range and get 0 movement even with the tires off the ground it dose not even try to move the driveshaft. Odd part is time it did go forward and backward when I was trying to figure out the steering and I am pretty sure that the trans light was still on when it was able to move. Thanks, James
Hi I would stick a pressure gauge on the trans pressure is to see what you have as this could point to the pressure switch for the light problem or something more serious . The particles you have if they are aluminium the only place with that is the clutch pack pistons which could also explain your no drive issue also a white bearing metal would be from the trans charge pump .Try a magnet on it as if its metal normally bearing/casing chewing its self a part When you have it running and select forward or revers can you here any noise from the gearbox spinning up as it could be a relay fault. A long shot the hand brake switch is working correctly try and link the switch out to test it as it wont drive with the hand brake on /faulty switch. But need to put a gauge on really to determine pressure first but with burnt brown oil it would appear you have a slipping clutch pack or packs . I guess this is a power shift which has rotating stalk for gears on the main f/r lever we used to also get probs with the micro relays the ones that look like half size oblong ones Few more checks but you may end up with gearbox out and strip rebuild though ,not too difficult if you have some good basic mechanical skills.
Trans pressure switch simple circuit not related to trans dump bur have a good look at the wiring from the joystick for the loader arm control you can access this from the panel along side the cab under the boom that the wiring has not chaffed and gone to ground allowing the dump circuit to operate just a thought .Try disconnecting the wiring plug at the base of the linkage also before that if you take the ignition buzzer out of the fuse box temporary so you can have ign on engine not running with hand brake off you should here the dump circuit relay operate in fuse board when pressing switch on loader lever
I got the new filter and fluid in the trans and still nothing I don't think it's the trans is out of it, I am starting to wonder if it has something to do with the trans dump you mentioned, also another question I have is on the shifter stack there is a push button on the end of the twist knob for 1-2-3-4 is that like a clutch you have to push to shift gears? I have no operators manual and I have never used this machine when it did function. It did back up and go forward once or twice when I was messing with the steering a long time back. The dealer here told me he though that might be the horn but after reading some JCB backhoes have a push button clutch for changing gears. Also my control for the boom has a trigger on it I have no clue what that's suposed to do is that something with the dump circut?. There is a couple switches on the dash one locks out the outriggers from going up or down, the one next to it has a picture of a joystick on it but it seems to do nothing. There is also a empty switch hole on the dash not sure if it's just the blank cover missing or there's supposed to be a switch there, dealer told me it's for a 4x4 switch but it seems like like there is no way to disconnect the front and rear on the telehandler, not sure if that's on a backhoe and he had it confused?
The button on the stalk with the twist gears is a horn button, the trigger is the trans dump switch for when loading a lorry ect when you want revs for hyds and travel without taking out of gear. 4x4 switch should be on the dash as a rocker switch this will energize or de energize a solenoid on the trans and a clutch pack to take in or out 4wd but you will also get 4wd when press the brake pedal so as to give you 4 wheel braking and when you take foot off brake it should disconnect usually test by putting front wheels up in air into drive in 2 wd and then put foot on brake and the rear wheels should push you along if working correctly some of the later ones the switch works back to front. As when messing with steering you did get it to drive have a good look at the stalk area pop the top section of dash off and have a look at the wiring on the stalk. So it looks like electrical fault for you Check micro relays /fuses and inside the stalk there are little micro switches which get worn if the stalk feels very worn in f/r movement have a look inside under the rubber boot as these often get broken and as the horn not works possible probs with stalk. Also check the hand brake switch as this will not let you drive with it faulty simple as a test bridge it out with a jumper wire .You may have a problem with the trans ecu this could either be under the seat housing or ontop of the gearbox.
I spent some time With the engine off you can hear clicks in the relays in the fuse panel under the dash when you twist through the gears the stalk or for forward and reverse. The more I think about it the trans dump on the trigger dosn't seem real springy of a switch I will spend some time there first thing. I didn't really understand how the dump worked I was thinking it was activated anytime you moved the boom, that makes more sense. I didn't see the trans ECU under the seat, I will look for it atop of the trans a bit more. I am thinking even without the 4x4 switch it should be fine to get the front wheels to drive for now, they were using this 550 as a parts machine for their other 2 in their fleet.I think the rear drive shaft went out so they removed it got long lost they kept using it only 2wd getting it stuck often I think that lead to it getting stuck in soft mud with one of the front wheels deep and when pushing it out with a dozer they busted the right front spindle from the track bar allowing the front wheels to sorta turn however they wanted, I thought that lead to the problems with the steering unit but those were apparently from once they parked it and started robing parts from it they tore the steering wheel all apart. I got most everything to fix that I still have to get the shifter stalk mounted somehow they lost the other 1/2 which I am told is for the wipers and stuff like that I think if I fassion a U bolt of sorts to hold it on the colum it will be fine. It was crazy some of the stupid **** the took off it to use on the others. I have been trying to gather stuff I NEED to make it work and stuff that would be nice to have. O new trans filter and fluid did fix the low trans pressure light it is off now so I am alot more optimistic that it is not an internal issue with the trans and electrical
The wiring for the dump circuit on the lift lever often rubs through as it comes out of the tube that the lever is made from if remove the long panel along side the cab you will access to loader valve block and should be able to see it there. Wipers and indicators on the right stalk and washer pump switch on the push button end. If you got s/no and model type I will see if I can dig out a fuse and relay id chart for you.
On the steering side, your test with L/R/T lines disconnected already tells a lot. With the pump feeding P and only return connected, you should see a clean, steady displacement of oil alternately from L and R as you turn the wheel, without the hard stop you describe and without both P lines going rock‑hard immediately. Hitting a hard stop to the right, very foamy oil from R, almost no flow out of L/R/T with open lines is exactly what shows up when an orbitrol is either internally mis-plumbed, badly air‑bound, or has an internal fault so most flow is trying to go somewhere it should not. On a 5‑port unit like yours (P, T, L, R and LS/feedback back to the pump), the basic checks would be: Make sure the actual pump pressure line and LS/feedback line are on the correct ports at the steering unit; if those two get swapped, the pump will try to react to the wrong signal and you can get the “rock hard lines and foamy dribble” symptom even with no cylinders connected. Bleed the steering thoroughly with the cylinders reconnected, full reservoir, and low engine rpm; trapped air will also give noisy, foamy discharge and strange feel, but it should not cause an immediate mechanical “stop” with lines open. If plumbing and bleeding check out and you still have no clean flow from L/R with lines off, then the orbitrol itself is the next suspect and is worth either bench‑testing or sending out, as you were planning. If you want a structured way to think through steering circuits like this (orbitrol internals, LS/priority, plumbing, cylinder sizing, etc.), there is a 7‑part hydraulic steering series that walks through the logic step by step using off‑highway equipment examples very similar to your Loadall: https://epichydraulic.com/steering/ There is also a steering calculator where you can plug in pump flow, steering unit size and cylinder dimensions to check expected wheel turns and steering response; you can use it for this machine just by entering your cylinder and pump data: https://calculator.epichydraulic.com/calculators/steering/hydraulic-steering-calculator