Lull 644 highlander Repaired boom

Hey my name is Pete and I just bought a older 644 highlander to use for framing. I had the machine delivered to my house today and noticed that the smaller cylinder that lifts the boom looks like it had broke off at some point and been repaired. It looks as though the carriage where the pin mounts to the base of the cyinder has been repaired and also at the top of the cylinder where it mounts behind the boom hinge has also been welded. The boom itself looks great and seems to operates the way it should but I haven't lifted any weight yet. I have seen a few other machines on some of the online sites that look like they have been repaired also. I am wondering what would have caused this to happen and if it could possibly give me problems in the future. If anyone knows about this type of problem and could let me know about it that would be great. I will post pictures of the repairs tomorrow.
Thanks Pete

You didn't include a picture, but by your description I believe you are describing the slave cylinder. It purpose is to transfer oil to the carriage tilt cylinder when you raise/lower the boom so the forks stay level. Beware that to do this correctly the cylinder bore and rod size can not be altered, so don't try putting something else on instead.

I don't have a schematic for that machine so I can't tell you for sure what will happen if it breaks again. If there is a counterbalance valve on the carriage tilt (about a 4x5 block welded to the cylinder) then the carriage should stop auto-leveling but it won't drop.

If it only has one slave cylinder I had heard that they where prone to damage in very cold weather, something about the thick oil and excessive back pressure, but I can't verify that. Others on here have more experience with these old ones then I do, hopefully they will chime in.

IceStationZebra

Thanks for the response. It is the slave cylinder for the carriage tilt and its funny you say that in cold temps it could be prone to damage because someone previously had installed a heater core/blower motor in the tool box and had also fabricated some sort of door and sealed the cab, all thats left of it now is the welded hinges and some old weather stripping. I did some more looking around the net today and have found quite a few machines that have the same repairs made. By the looks of what has been repaired either there was some serious back presure due to cold thick oil or is it possible the cylinder malfunctioned? from what I see on other machines of the same model its a fairly common problem.
I took a few pictures today before it got dark, everything looks real strait and inline but the one concern I have is that the cylinder is touching the inside of the carriage. Is this normal or could something be out of whack? Also Im having trouble finding what year this machine is. The serial number is JD2517N. It doesent seem to work with the chart.
Any help would be great thanks
Pete

Here are the pictures of the repair.

That serial number doesn't decode with either of the SN sheets I have. The serial number should be on a plate behind the seat.

How hard is the slave cylinder rubbing? If it is only trading paint I wouldn't worry about it. But if it is rubbing harder that isn't good for the rod and seals, you would have to try adjusting the shimming to get a little more room. Probably moved over a little when they did the repair.

I didn't find a hydraulic schematic, but looking at a parts manual I did confirm that the carriage tilt has a counterbalance valve. So even if the slave rips off you shouldn't drop a load and hurt anybody. If you are really worried about it you could go with thinner oil in the winter. The tradeoff is during the summer it would be harder on the pump and leakage would increase a little.

ISZ

This machine was sold to a customer in Michigan on 3/2/89

Thanks for the date. I haven't been able to check on how tight the cylinder is to the carriage but If you look at the space between the end of the cylinder and the boom it looks as though there is about 1/2" of space that has filled with grease. My question is how should I go about trying to shim the cylinder back to the boom. I feel like that is probably due to the base pin repair not being lined up right when it was welded, or the heat pulled it a bit maybee? Any way to shim the cylinder without major fabrication? should the pin at the top just be shifted over to close the gap? Any insight or ideas to get me thinking about the best way to do this would be great. That is if I even need to. Going to go out tonight and check how tight the cylinder really is and Ill check back in a few hours. Thanks again for the help.
Pete

Pete- can you get a pic of what your describing? I can't say I follow what your describing.

Sure Im talking about the last two pictures that I posted. One shows the slave cylinder touching the carriage and the last photo shows the end of the slave ram and the gap where it attaches to the boom that looks as though it is filled with grease. Im thinking that the cylinder base pin connection has been repaired out of whack a bit but im not sure yet. Im hoping its not really a big deal. Im going out now to clean up some messy wiring and ill poke around the slave cylinder and let you know what I come up with.
Pete

I'd have to say its internal wear.....but with the age of this machine and the fact that I'm not 100% familiar, my advise would be to have a service tech take a look at it if your in question.

I messed around with the slave cylinder a little bit tonight and right now its a little more than trading paint. I believe the problem is at the big pin at the boom attachment but it was to late to get into it. the way the base of the cylinder attaches to the carriage should allow the cylinder to move where it needs to be I just dont know yet how to do that. Im gona do some more research and try to figure out what is going on. Thanks again for the advise I appreciate it. Ill post it when I come up with the solution... Hopefully
Pete

So I got a update with a question on what I have going on. The slave cylinder for the carriage tilt was put back together at some point without the bushing properly in place. That is why the cylinder is away from the boom and rubbing on the carriage. The bronze bushing for the cylinder was not pushed into the end of the ram and when the pin was pushed on the bushing got sandwiched between the boom and the cylinder ram. My question is what is the best way to remove the large pin that holds the slave cylinder to the boom and what is the best way to press in the new bushing inside the cylinder ram. any advise would be great.
Thanks, Pete

from other pics I see on the web it looks like there is a bolt on the left side, which needs to come off first. Then see if it slides out. I don't see one in the pics, but next I would look for a tapped hole in the end for a slide hammer. Next option is a brass drift and BFH. (If you use steel make sure you dont mushroom the pin or it will gouge the bore.)

As far as installation goes at the factory we normally use nitrogen to shrink the bush and drop it in. Alternatively you can try to gently heat the eye, trying not to get the weld too hot. Pressing would be the last option as with you will likely shave off some metal and loose the press fit, and it will work its way out.

ISZ

Hey guys, heres the update and I also got some new questions. The replasement bushing came in yesterday and I was able to get that job done last night. Lucky for me it went way easier than I was expecting. I am slamming at work right now and I got three little boys at home so my time is scarce, but right after work yesterday I had a friend give me a hand punching the pin out with a steel bar and the biggest sledge I could find before I had to pick my boys up and I also put the new bushing in the freezer. So at about 8pm last night I turned on the lights and went back to work. I was able to get the old bushing out of the eye by kerfing it with the sawzall and punching it out. Then I cleaned everything real good and got all the grease and rust off the big pin. After that was done I brought the bushing out of the freezer and coated it with some vaseline and it went in with just a couple pieces of plate and a c clamp. I thought I was gona have to heat the eye but it went in pretty easy. After that I sent the big pin back home and the problem is fixed. I just need to get some shims when I go back to the dealer for a water temp sensor that is on order. In the mean time I have built a man lift basket for it and when I was testing it out I noticed the bushings at the base of the frame tilt cylinder are sloppy so thats the next fix but should be fairly strait forward. While going through the machine I found that the boom lift cylinder has also been repaired at some point. The eye on the cylinder looks as though it has been welded back on the ram, and the front of the transfer carriage has a pretty good dent in it from someone pushing the broken ram into it. I think this may have something to do with the repaired slave cylinder mount, but how does that happen on a fork lift? I know it seems scary but the repair on the cylinder looks professional like it was done in a shop I dont think most people would have even noticed it but I'm anal and try to look for every stupid thing I can find. Also Im having a hard time getting the transmission oil temp gauge working. I have power/ground to the gauge and have continuity to the censor but it wont work and my manual dosent tell me how to test the sensor. Does anyone know how to test the censor or have any other suggestions on how to get the gauge working?
Thanks Pete

Most likely it tipped over forward. Some people try to use telehandlers to compact roll-offs, though that shouldn't be enough force to pull it off.

I don't know exactly what temperature sensor/gage set-up is in your machine, but most of the sensors vary their resistance with temperature. Use a basic meter and measure the ohms between the sensor output and body. If it is very low (<10 ohm) or very high (>50,000 ohm) the sensor is probably bad. If it is a one wire sensor you should get near zero ohm between the sensor body and battery ground. You can test the gauge by replacing the sensor with a known good sensor (ground the body if one wire) or a resistor (probably in the 200-500 ohm range).

With regard to the manlift basket be aware that what you are doing is not OSHA legal and you could get a big fine. And if someone working for you gets hurt you will be soley liable. Also, by OSHA rules the whole time someone is in the backet you are required to have an operator within a short distance. (I can't remember, 20-30ft?) When I worked for Lull I heard of a couple accidents from this exact thing and of course the permanently disabled worker, or widow and kids, came looking for a settlement. :crying:crying If you absolutely insist on building it yourself please make sure at a minimum it gets securely chained to the backrest.

Not trying to be a jerk but I don't like people getting hurt over saving a little time or money. My family got lucky that the only permanent disability we got from the farm is some hearing loss, but lots of accidents and near misses. And I've had enough coworkers get lucky with near misses.

be safe
IceStationZebra

If a man basket is mfg w all the engineering and stickers & labels, then I conjecture the next issue will be approval of the OEM not designating the manbasket....
From what we understand, the rule disallows the use of the forklift with personnel with the manbasket but isn't it really the "driving with the folks" that causes the risk exposure? Most everyplace we know clearly prohibit forklift operation other than up and down when using manbasket occupied.

Or are there other issues that merit discussion such as variants in hydraulic valving, etc when comparing manbasket on forklift to a say scissor or boom lift?

Like Oceanobob says you can have people in a manbasket only while stationary and the driver must remain near the machine to lower them quickly in an emergency.
I've been out of the forklift industry for 5 yrs now, but as I recall the hangup is that OSHA requires attachments to be OEM approved, and there usually isn't any incentive for an OEM to approve an attachment from another company. This goes for non-standard forks, fork extensions, man-baskets, truss booms, buckets, etc. For good or bad OSHA has been allowing 3rd party attachments as long as they are tagged by the manufacturer. (At a minimum they have to tag the attachment with the manufacturer's name, attachment weight and if applicable max hydraulic pressure.) But the consequence is the OEM's liability will be significantly reduced if you have an accident with a 3rd party attachment installed since the manual clearly states not to. Also if you read carefully it also says that you are not allowed to drive with a suspended load.

ISZ

In the construction business we find there is an awareness of these policies...but from the many experiences in the warehouse world, it seems the limit is the imagination....those folks scoff at the need to change a nameplate or get an OEM's agreement. Interesting dichotomy.

OSHA also requires all attachments used to be approved by the original manufacturer. I doubt this happens at all. So really all aftermarket attachments are not legal. There is also something about if you make something to have to prove the engineering of it which most all except a manufacturer could do.