Since nobody talks about lifts i guess i will! I have a Gehl 1155 telehandeler and it has trouble retracting the boom when it is close to parallel with the ground. My assumption is the Valve (something or another i cant think of the name) mounted on the side of the extend retract cylinder. What is your take on that. Seems like all my mechanic problems are answered right away and are always right! So i figured i would try again
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Nobody talks about lifts
- Thread starter barklee
- Start date
willie59
Administrator
Do you mean a DL11-55? Haven't had the boom cyl out of a DL, pulled them out of 663's though, doubt they're much different. Are your boom sections straight, not bent excessively? Are your wear pads allowing too much droop in the extended boom? Both of these can get the cylinder in a bind when it's extended causing problems retracting boom.
willie59
Administrator
Wow, haven't seen one of them. Any valve body mounted on the telescope cylinder would be the holding valve. Don't know much about this machine, the valve body could even have a regeneration valve in it, that's a big maybe. Are you saying the telescope cyl is outside of the boom? If so, have you checked for excessive boom deflection causing cylinder bind? Pics of this would be cool as I have no experience with this model.
I will get a pic tomorrow. the cylinder does the same thing as the cylinder mounted to the bottom of the boom of a lull 10000 lb lift. The "valve" is about 2" tall and 2" in diameter. if i remember right it has a nut on the top
willie59
Administrator
If your describing a single valve, like a single cartridge valve, it sounds like a holding valve for the telescope cylinder. If it's a single cartridge holding valve for the telescope cylinder, not a counterbalance or crossover relief, about the only things that would cause that valve to affect boom retraction is valve is defective or it has failed o-ring seals for the pilot control portion of the valve that unlocks the valve during boom retraction. I wouldn't hestitate to pluck the cartridge out and check the o-rings and backup rings, I've seen plenty of failures of o-rings and backup rings on this type of valve.
willie59
Administrator
hmm, set forks on ground and relieve weight on boom and it retracts slowly. Interesting. The wear pads? You just want to make sure you don't have wear pads that are worn to the point of making excessive boom droop when extended. If you have boom extended, boom sections are not bent, and the sections don't have abrupt nose dives from extended sections (from worn pads), then your pads are Ok. When the boom is extended and horizontal, it's not going to be totally straight, it will droop, but not excessively. Pluck that holding valve cartridge out and check the o-rings. If you have failed o-rings, it will be obvious. We'll start with that.
Checked the holding valve and it looked good. I noticed that if you bounced the boom it would retract easier. I called Gehl and they said that this being a 4 section boom it may not want to retract being fully extended and horizontal (what kind of crap is that!) also they said to check the relief pressure and it should be 3300psi. SO i will do that over the weekend. Seems to me if its binding somehow. I cant find anything visual to see a tweek in the booms. How do you tell if the wear pads are bad or causing a problem? This machine only has 600hrs on it so it would supprise me if the pads were bad.
willie59
Administrator
Ok, you contacted Gehl, they said it being a four section boom it "may" have a hard time retracting near horizontal. Wait a minute..."may"? You built the thing, will it or will it not have a hard time retracting...what's this "may" stuff? :beatsme
I can see where it's possible for it to be difficult retracting. Three telescoping sections stretched out does create considerable friction. Then again, build the darn thing heavy enough to suck the boom in for pete's sake! I mean, a JLG 80HX doesn't have any problem retracting 80 feet of boom flat out. Do we have an inadequate design here? That's what bugs me about that "may" response. How are we supposed to know what it is "designed" to do with a "may" response? :Banghead
For sure, check the pressure by tee-ing into the lines, right at the cylinder if possible, and make sure the pressure is at spec.
Do you have a hyd schematic for the machine? Since Gehl is of little help, we really need to see what type of valving they have at the telescope cyinder, such as, is it using crossover reliefs or just internal pilot operated holding valves. This info is invaluable in troubleshooting something like this. :yup
I can see where it's possible for it to be difficult retracting. Three telescoping sections stretched out does create considerable friction. Then again, build the darn thing heavy enough to suck the boom in for pete's sake! I mean, a JLG 80HX doesn't have any problem retracting 80 feet of boom flat out. Do we have an inadequate design here? That's what bugs me about that "may" response. How are we supposed to know what it is "designed" to do with a "may" response? :Banghead
For sure, check the pressure by tee-ing into the lines, right at the cylinder if possible, and make sure the pressure is at spec.
Do you have a hyd schematic for the machine? Since Gehl is of little help, we really need to see what type of valving they have at the telescope cyinder, such as, is it using crossover reliefs or just internal pilot operated holding valves. This info is invaluable in troubleshooting something like this. :yup
Speedpup
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Tell them if you only needed to retract it when up gravity would do it!
You should have told them they should label the machines when in the showroom DO NOT RETRACT BOOM WHEN LEVEL
ointhead I would call back and ask a bit up the chain there to see if they give you the same answer. Also ask them if the boom designer is still employed there.:Banghead:Banghead:BangheadDoes it just happen when loaded?
Last edited:
icestationzebra
Senior Member
Obviously the force to retract a boom is greatest at horizontal, but it is also worse with worn pads due to the angles. I would check the boom boxes for gouging, pad material being transferred onto the box sections, or paint migration/galling - all bad. The upper rear pads are the most critical. Also check the side pads, but they are probably OK. There is no problem with shimming them too tight unless they start to bind. Just have someone run the boom in/out while you watch the gap.
And I second the recommendation to check the relief pressure.
You might also try greasing the pads, but this is a catch 22 as the grease will attack and hold onto dirt. A dry lubricant would be best but I don't know how you get it 15ft inside the boxes! At Lull we messed around with putting two little holes in the top of the boom box. You could then extend the boom, lower the forks to the ground, and pump a bunch of grease on top of the rear upper pads.
The cartridge on the extend cylinder is almost certainly a counterbalance valve. Could also be a pilot operated check. In either case I doubt it is the problem since it tends to either chatter or stick. To create your problem it would need increased spring force without sticking, which is very unlikely.
As far as Gehl goes I am not very impressed with their machines, except maybe the RS5-19. They haven't change much in the past 15yrs. But I will say they do use a lot of iron, but that doesn't always prevent issues from happening.
ISZ
And I second the recommendation to check the relief pressure.
You might also try greasing the pads, but this is a catch 22 as the grease will attack and hold onto dirt. A dry lubricant would be best but I don't know how you get it 15ft inside the boxes! At Lull we messed around with putting two little holes in the top of the boom box. You could then extend the boom, lower the forks to the ground, and pump a bunch of grease on top of the rear upper pads.
The cartridge on the extend cylinder is almost certainly a counterbalance valve. Could also be a pilot operated check. In either case I doubt it is the problem since it tends to either chatter or stick. To create your problem it would need increased spring force without sticking, which is very unlikely.
As far as Gehl goes I am not very impressed with their machines, except maybe the RS5-19. They haven't change much in the past 15yrs. But I will say they do use a lot of iron, but that doesn't always prevent issues from happening.
ISZ
willie59
Administrator
Should be able to view rear pads by removing the cover on rear of boom with boom retracted.
Framer
Well-Known Member
Rented one of these things for a month. I was supposed to rent a 8000 lb machine but they didn't have one. The machine came equipped with solid rubber tires, so it was a good thing it had the reach because I couldn't get close to the building because the machine kept sinking out of sight. I had the exact same problem with the boom, it did come back but very slowly with a lot of right pedal. The other thing I noticed was that it was very slow (about as fast as my manitou hydrostatic in turtle gear aka 2 of 4) in high gear when I tried to road it. It was also poor on fuel economy @ 15hrs to 110 litres whatever that is in gallons. My perkins uses about 24 hours to 115 litres. Note however my 10-54 manitou weighs 24500lbs and the gehl weighs about 32000lbs but I dont think it should make that much of a difference. I might also be rougher on a rental machine in some ways then I would be on my own. The boom retraction issue seamed like it was maybe a chain issue. I dont know who decided to put solid rubber tires (like skidsteer tires) but I had to be pulled out by bigger machinery 6 times. My Manitou has never been pulled out in almost 3 years now. One time I had to dig it out of the snow because the snow was up to the undercarriage. Manitou expensive and well built for the most part, gehl cheaper but maybe more time consuming with more fuel refils (time), slower roading and boom problems, If thats wrong with the boom brand new than what other problems my there be in the design.
willie59
Administrator
Sounds like an interesting mess ya had Framer.
In my experience with Gehl's, I've never been fond of the DL series machines, I much prefer the RS series. The RS machines are predecessors of the old 663 and 883 Dynalift design. The old 663 was built like an anvil. I used to work on a contractors fleet that had newer DL-8 and 2 older 663 machines. The oldest 663 they had was half worn out, but it was a daily driver, and had less problems than the new DL's. The newer RS machines may have newer and different components as opposed to the older 663 machines, but the machine design has remained, and in my opinion, the design makes them easier to perform repairs.
In my experience with Gehl's, I've never been fond of the DL series machines, I much prefer the RS series. The RS machines are predecessors of the old 663 and 883 Dynalift design. The old 663 was built like an anvil. I used to work on a contractors fleet that had newer DL-8 and 2 older 663 machines. The oldest 663 they had was half worn out, but it was a daily driver, and had less problems than the new DL's. The newer RS machines may have newer and different components as opposed to the older 663 machines, but the machine design has remained, and in my opinion, the design makes them easier to perform repairs.
The Gehl/ Mustang is 50% owned by Manitou as i understand. The DL-1155 is a Manitou design. The only thing different is the paint. This is what the Gehl rep had told me, said he knew that since mine was a low profile boom. To be honest i really like the machine from an operating standpoint. Mine has the boom controls for a man basket which is nice. The cab and controls are really smooth and comfortable. The only thing i dont like is that its a little lighter in the rear than a Lull (bout the same as a Skytrak), oh yeah and the boom wont retract! It handles alot better on the road than a Lull or skytrak and overall is quite a bit easier to manuver. Also its better in the mud. This one has the Deere motor which we have had great luck with and the Clark trans (not the ZF). The ZF are great but pray that it never ever breaks. I just thought a change would be good after being nickeled and dimed over and over on our Lulls.
willie59
Administrator
Yep, you mention all the things I like about the Gehl telehandler, they are good machines. I just have a mechanical preference to the RS as opposed to the DL, but your right, the DL is a sweet operating machine. Do you have a hyd schematic for your machine?
Dont get me wrong, Lull is a sweet machine expecailly the new 6 and 8. The 10's are just boat anchors. They are really hard on rear ends, axles, u joints, basically anything that involves the drive system. They are pretty good to work on with the traversing boom.
I might i will have to look and see the service manual. I really dont think they are worth 20k more to buy one when we run them till they have 4000- 5000 hrs.
I might i will have to look and see the service manual. I really dont think they are worth 20k more to buy one when we run them till they have 4000- 5000 hrs.