'94 Lull 644 Highlander II won't move

[spock]

Hello All,

I'm looking for some help with my Lull 644. Last spring it started intermittently not responding when I put it in gear, but it seemed that the more the machine was used, the less this occurred. At the job the machine is at now, everything was working normally most of the time, but occasionally the machine would pop out of gear with the stick not being moved. Usually slipping the stick back and forth from neutral to forward or reverse would solve the problem until the next time. This morning, it would not go into gear no matter what I tried. Last year when it was not moving for a few days, I tried a different gear shift lever assembly, and it didn't help. If anybody knows what I should try next, I'd appreciate hearing from you. Thanks.

Best Regards,

Spock

 

[skata]

is the trans fluid level ok?

does this machine have an electric forward/reverse lever? or it is mechanicaly linked?

 

[spock]

Now that you mention it, I replaced a burst hose last week, and the trans fluid level is down, but still above the low mark on the sight glass. I'll top it up this morning. The forward/reverse lever is electric. Thanks for your response.

 

[spock]

Does this machine have trans fluid separate from hydraulic fluid? I assumed everything was run form the hyd fluid, but maybe this is not the case?

 

[skata]

Does this machine have trans fluid separate from hydraulic fluid? I assumed everything was run form the hyd fluid, but maybe this is not the case?

while i'm not too familiar with the lulls, most lifts operate the same.
usually the transmission fluid is seperate. check the fluid level, and after that i'd check the selector lever to make sure its working. the lever triggers solenoids on the trans to make it move.

 

[spock]

When I got to the job this A.M. I located the trans fluid dipstick, checked the fluid level with the machine running in neutral, and there was no fluid showing on the stick. After filling until the proper level was reached, I shifted the machine into gear, and after a few attempts, it worked. Initially the machine wanted to slip out of gear a lot, but shifting the lever into neutral, then back into gear would eventually work. When I used the machine at the end of the day it seemed to be working better; I guess we'll see tomorrow how it goes. Anyway, thanks again for your response. I need to print out a manual on this machine and become more familiar with its systems. This was a basic maintenance check that I should have been on top of.

 

[spock]

Machine worked about the same today. It's being used to hold/move our scaffold platform, so it doesn't see a lot of sustained use at this job. It is usable, which is a huge improvement, and when it slips into neutral, clicking the selector lever back and forth a couple of times seems to get it back in gear. If I can figure out a way to test the selector, I'll try that next. Just need to find a selector that I know is working on another machine, and borrow it for a day.

 

[spock]

Machine was working normally Friday morning, but when I tried to use it in the afternoon, it would not go into gear. I brought the gear selector home and opened it up, found two micro switches inside which appear to me to activate the forward/reverse functions. I tested them with a continuity tester, and they both appear to be working. There is no corrosion or loose wiring in the selector, so I reassembled it, and am looking for suggestions about how to proceed. My plan is to find where the wire harness from the selector goes into the transmission, and make sure all the connections and grounding points look okay. I know that there are some coils under a cover which may need to be checked out, but I'm not sure how to do it.
Thanks,

Spock

 

[skata]

look around the trans. i'm not sure if the solenoids are internal or external on the lulls. at least check to make sure the wire connection looks good.
another thing, do you have a parking brake on the machine? usually there is a electric cutoff switch mounted on those, to prevent the trans from engaging when the park brake is engaged. i've seen those cutoff switches get stuck/corroded before.

 

[spock]

There is a parking brake. It is a manually controlled hydraulic valve, I'll check to see if there is a switch in the system.

Thanks

 

[spock]

Checked and cleaned every connection I could find and access, with no luck. The 5 solenoids are mounted up on the side of the trans, under a cover that looks like a valve cover. I opened the cover, and the connections looked fine, so I unplugged each plug and stuck the test prongs of an ohm meter into each plug with the meter on the ohm setting. Each one read the same, as did the solenoids themselves. Bear in mind that I have absolutely no idea what I am doing, and am just trying to find some kind of smoking gun so that I can get this machine working. I could not find any wiring or switches connected to the parking brake. The machine will not normally go into gear with the brake on, so I know that there is some kind of relationship there, but I can't tell how it works. Moving the parking brake handle in and out makes a lever between the brake and the trans move up and down. This trans is German made, "ZH" possibly, and I don't see an external filter. Could there be an internal filter/screen which is completely plugged due to my poor maintenance? The reason I'm suspecting something electrical is because of the intermittent nature of the failure. Friday A.M. it worked perfectly, and later that afternoon would not go into gear at all. Thanks for any suggestions.

 

[curb guy]

I had the EXACT same problem on an 844. Almost drove myself to drink(more).I'm not certain exactly ,100%, I tinkered so miuch with this that I kinda lost track, but I think the following might help. Now bear in mind ,this is an 844, not sure if yours is the same. Under the dash there is a bank of relays. When you switch between forward, neutral, reverse, with the key in the on position, you should be able to hear them click. If not, try laying your hand on them and see if you can feel them click. It may be one of those relays.Also, on the floorboard there is some sort of electrical controller, I have no idea what it is, but try taking the metal cover off and see if there is any sign of moisture. When I did this I discovered a leak in that allowed rain water to run down and get trapped in there. I dried it out real good with a fan, sealed the leak and ,so far so good.I hope this helps, cause it made me crazy trying to figure it out.Again, I hope this helps!

 

[spock]

Thanks for the reply, Curb Guy. Last thing I tried was unplugging every wire harness plug I could reach, and spraying electrical contact cleaner on them. Machine went into gear, and worked fine... for a while. Just when I was about to pat myself on the back, it started slipping out of gear, and clicking the selector back and forth would pop it back into gear for a while. I think the metal box on your floorboard is the "brain box" computer. Mine has a big gob of wires coming into it, and a plug which I opened up and sprayed. I'll check for the relays, but I don't remember seeing them under the dash. This is a nasty problem, and maybe I need to consider drinking more - at least I would end up with a real headache to go along with my mechanical one.

 

[icestationzebra]

Sorry, but I don't have any experience with these older machines. One possibility is you could have a gear selector going bad, it is a wear item.

If you want to verify whether or not it is an electrical issue, you could check the coils when it works correctly. A quick way to check which solenoids are on is to 1) leave the engine off, 2) put it in gear with the brake off, 3) then put a small screwdriver near the end of each coil. If the coil is energized you will feel it pull on the screwdriver. Note which coils are energized in each gear. (forward 1, forward 2, etc.) Then when it doesn't work right check it again. If the correct coils are still working it is mechanical.

ISZ

 

[spock]

Thanks for the method of checking the coils, ISZ. I'll give it a try.

 

[spock]

I'm not using the machine at the job I'm on, but went over to it this evening, and it worked fine. Ran it in all gears, forward and reverse probably 50 times for 20 or 30 minutes. There are no relays under the dash on this machine, only the brain box, and I couldn't hear or feel any clicking when I turned the key on and switched the selector through forward/ neutral/ reverse. I tried checking the coils to see if I could feel them pulling on my pocket knife, but must have been doing something wrong, because I couldn't feel anything. I am not kidding myself into believing that I've seen the last of this problem, but the machine will go back to work in a week or so, and we'll see what happens. Thanks to everyone who came up with a suggestion - I'll probably be looking for more wisdom if (when) this starts acting up again.

 

[curb guy]

That is so bizzare, I'm tellin' you that is what mine did.It would work fine for 1 day,1 month, 1 hour.I did that too,with the selector/shifter. Are you sure there are no relays? There should be a few relays and some fuses. You need to lie on your back on the floor and look up,if they are there.If it flares up again,take the cover off that box and put a fan on it for a while,the longer the better. I'm tellin ya,I really think that was what fixed mine!

 

[spock]

Update-
Used the machine for an hour today; worked without a problem. Went about a mile down the road to do some measuring at the next job site, no problems selecting gears, and never popped out of gear, so maybe things are looking up. Weather is supposed to get nasty, maybe even some snow tomorrow night, so we'll see if moisture makes it act up again.

 

[boerkman]

I have the same machine and developed the same problem 2 months ago. Been drinking more since. Did dying it out fix your problem?

 

[spock]

Hey Boerkman,
What finally got it going again last fall was to open every plug connection I could reach, and spray them generously with electrical contact cleaner. The big plug that comes right out of the brain box is the one I cleaned when the machine froze up last, and as soon as I plugged it back together, the machine worked fine, and hasn't acted up since.