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The JLG 40F Boom Lift Dilemma

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
Drive Speed
I haven't posted here in a while because my 40F has been working pretty good for an old gal, but it's always been a little slow traveling. Now it's gotten to be painful to move it any distance at all, it moves maybe 1 mph max forward, and in reverse about half that. I'm kind of leaning toward the motor system because the other 2 proportional functions (lift and swing) are pretty good, and if I'm not mistaken, work off the same dump valve. If I kick the RPM up it helps some, but if I switch to "hi drive" it just loads the engine down. Any ideas will be much appreciated!
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
Drive Speed
I haven't posted here in a while because my 40F has been working pretty good for an old gal, but it's always been a little slow traveling. Now it's gotten to be painful to move it any distance at all, it moves maybe 1 mph max forward, and in reverse about half that. I'm kind of leaning toward the motor system because the other 2 proportional functions (lift and swing) are pretty good, and if I'm not mistaken, work off the same dump valve. If I kick the RPM up it helps some, but if I switch to "hi drive" it just loads the engine down. Any ideas will be much appreciated!

Sounds like more of a controller problem to me, like the drive valve isn't being opened more than a little bit. What brand of controllers does your machine have? Racine proportional valves?? First thing I would do is compare the drive controller output to the output of the functions that work well (lift & swing)
 

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
Sounds like more of a controller problem to me, like the drive valve isn't being opened more than a little bit. What brand of controllers does your machine have? Racine proportional valves?? First thing I would do is compare the drive controller output to the output of the functions that work well (lift & swing)

Thanks Off, the controllers are Racine. I think I remember checking the output of the controller before but I'll check it again. What's confusing me now is that the hi drive just loads the engine down and doesn't make it go any faster. I'm guessing that the 2 may be related. Also, the other functions "seem" to work ok. That's an assumption on my part because I have nothing to compare them to, for instance, how long should it take to swing 360 degrees, or to raise the basket to 45?
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
Thanks Off, the controllers are Racine. I think I remember checking the output of the controller before but I'll check it again. What's confusing me now is that the hi drive just loads the engine down and doesn't make it go any faster. I'm guessing that the 2 may be related. Also, the other functions "seem" to work ok. That's an assumption on my part because I have nothing to compare them to, for instance, how long should it take to swing 360 degrees, or to raise the basket to 45?

the bogging down in high drive is what makes me think the valve is not getting a signal to fully open. With the valve only slightly open, a certain amount of oil will pass no matter what. When you kick in high drive, it doubles the volume of oil trying to get through that restricted valve. The oil backs up, the engine boggs down. I'm assuming your pressures are good because the boom will lift. When pressures drop off the first thing to go is boom raise. It requires the most effort. The manual states the boom should go from ground level to maximum elevation in 60 seconds. maximum elevation to ground in 45 seconds.
Speed is listed as 0 - 1 mph on low engine, 0 - 3 mph on high engine, not very fast at all.
 

dbris

Active Member
Joined
Mar 27, 2010
Messages
32
Location
Los Angeles
the bogging down in high drive is what makes me think the valve is not getting a signal to fully open. With the valve only slightly open, a certain amount of oil will pass no matter what. When you kick in high drive, it doubles the volume of oil trying to get through that restricted valve. The oil backs up, the engine boggs down. I'm assuming your pressures are good because the boom will lift. When pressures drop off the first thing to go is boom raise. It requires the most effort. The manual states the boom should go from ground level to maximum elevation in 60 seconds. maximum elevation to ground in 45 seconds.
Speed is listed as 0 - 1 mph on low engine, 0 - 3 mph on high engine, not very fast at all.

I did some testing today. The boom goes all the way up in 45 seconds and comes down in 31, that's with the boom retracted and the engine at slow. It swings in a full circle in 1:20 sec. The speed forward is just under 1mph and with hi drive it's about 1.3. Reverse is about 1/2 mph slower. Of course the speed varies depending on her mood and she was in a good mood today. The swing seems kind of slow but with the boom extended it can still be exciting, so I think that it's fast enough for me. I didn't have time to check the controller today but I'll get to it next week and let you know what I find.
Dave
 

die5el3

New Member
Joined
Feb 9, 2008
Messages
1
Location
Berks County, PA
Hello OFF, Any chance I could get the copies of the manuals for the 40F as well? (XXXX.com) I am particularly in need of the parts manual; need to rebuild the steering cylinder.
I notice JLG has a lot of manuals online, but not for some of the older models. http://www.jlg.com/en/parts-services
Thanks.
 
Last edited by a moderator:

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
Hello OFF, Any chance I could get the copies of the manuals for the 40F as well? I am particularly in need of the parts manual; need to rebuild the steering cylinder.
I notice JLG has a lot of manuals online, but not for some of the older models. http://www.jlg.com/en/parts-services
Thanks.

Welcome! Manuals are on the way. You may want to edit your post and remove your email address. Good luck with your 40F
 

willie59

Administrator
Joined
Dec 21, 2008
Messages
13,361
Location
Knoxville TN
Occupation
Service Manager
You may want to edit your post and remove your email address.

Too much time has passed for him to edit a post, but I removed the email addy now that now that you've sent the info. :drinkup
 

joelwwilliams

New Member
Joined
Oct 24, 2012
Messages
4
Location
Illinois
Hey OFF was also wondering if I could get a copy of the manuals for the jlg 40f? Having a problem when I move the telescoping cylinder oil is pouring out of the bottom of the turntable motor. Any additional ideas or advise would be greatly appreciated. Thanks
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
Hey OFF was also wondering if I could get a copy of the manuals for the jlg 40f? Having a problem when I move the telescoping cylinder oil is pouring out of the bottom of the turntable motor. Any additional ideas or advise would be greatly appreciated. Thanks

Hi Joel, sure I'll be happy to send you the manuals. Just send me a Private message with your email address and they're yours. You must have a bad hose someplace. I'm thinking if the telescope cylinder was leaking the oil would pour out the boom, not the turntable. Watch from a safe distance, and if you're moving hoses around with the engine running - always use a stick, not your hand.
 

joelwwilliams

New Member
Joined
Oct 24, 2012
Messages
4
Location
Illinois
I've looked pretty hard in hope for leaking hose but cannot find any. The only places I see the telescoping oil and turntable motor could come together is the manual descent valves or the solenoid valve block. I plugged off the two hoses going to the manual valves, thinking a valve might be bleeding by but no luck. I'm also thinking maybe the manual could give me an idea about a possible check valve that let go. Rather than getting into the solenoid valve block.
 

rgh

New Member
Joined
Jul 7, 2014
Messages
3
Location
michigan
Hi OFF, I've just acquired a 40f of my own. Most everything works, but it has a cobbled mess of wiring. Looks like a lot of valued engineering. Foot pedal disconnected, Alternator not working... looks new, but may be miswired. I would really appreciate it if you would send some manuals. Serial #765820. Does that make it built in 82? Thanks, Rob
 

rgh

New Member
Joined
Jul 7, 2014
Messages
3
Location
michigan
Need to get my 3 posts in so here's another question. Noticed the machine didn't want to move real well and only one tire was spinning. Removed the hub and found the planet carrier missing from one side. Any thoughts on where to find one?
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
Need to get my 3 posts in so here's another question. Noticed the machine didn't want to move real well and only one tire was spinning. Removed the hub and found the planet carrier missing from one side. Any thoughts on where to find one?

Hi Rob, Welcome to the forum! 1 more post and then private message me your email address and I'll send you the manual set. Sounds like your machine needs a bit of work. I wish you luck finding that planet carrier. Maybe someone here knows where there is a parts machine with the hubs still on it. That's going to be a hard to find item for sure.
 

rgh

New Member
Joined
Jul 7, 2014
Messages
3
Location
michigan
I did find a used one for sale in Kentucky that looks to be the same. Maybe he will part it out or for the $1500 bucks just buy it for spare parts. Do you know if the years have to match for the part to match or did they use the same carriers for different models or years? Any ideas on the year of my machine off the serial#? Thanks!
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
I did find a used one for sale in Kentucky that looks to be the same. Maybe he will part it out or for the $1500 bucks just buy it for spare parts. Do you know if the years have to match for the part to match or did they use the same carriers for different models or years? Any ideas on the year of my machine off the serial#? Thanks!

I would recommend you put on the whole hub/planetary assembly from the other machine. Or if both are good on the parts machine I would even change both on yours to stay as a matched pair. Hubs do come in different ratios and JLG is famous for having components supplied by more than one manufacturer. You don't want to be instaling a brand X carrier ring into a brand Y hub.
 

excavator

Senior Member
Joined
Oct 16, 2006
Messages
1,445
Location
Pacific North West
I've been rewiring a 60F for my brother-in-law and the Racine controllers are questionable to say the least. They are the same as the 40F, the JLG part number is 1600001. I'm wondering has anyone tried installing newer style controllers? I saw a dead one at an auction that had different ones but they had no part numbers or anything on them and being dead really couldn't test it to find out how well they worked. Any thoughts?
 

OFF

Senior Member
Joined
Sep 30, 2009
Messages
1,047
Location
Alberta, Canada
Occupation
HD Mechanic
I've been rewiring a 60F for my brother-in-law and the Racine controllers are questionable to say the least. They are the same as the 40F, the JLG part number is 1600001. I'm wondering has anyone tried installing newer style controllers? I saw a dead one at an auction that had different ones but they had no part numbers or anything on them and being dead really couldn't test it to find out how well they worked. Any thoughts?

Well, I've never tried changing brands of controllers, but JLG used both Racine & PQ controllers on "F" series manlifts with Racine valves. I could see changing to "F" series era PQ controllers.
However,
Later JLG's - the "H" series (ones that still used Racine valves before they changed to Vickers) used coils of a different value in the valve pilot sections so they would not work. Newer than that? I do not know.
 

Jonesy

Member
Joined
Apr 19, 2014
Messages
18
Location
Perrysburg, OH
Progress has been slow on rebuilding my 40F, but things are moving along. I have traced all the wiring from the basket to the relay board, and pulled all of the wiring and basket operator switches. I've procured SAB wire to replace everything. Since the basket has been severely damaged, I'm going to pull that off next, pull the two hydraulic lines, and paint the boom. I found a switch down inside the control tower that had been taken out of service. I think it's a high/low speed switch for forward/reverse ground movement. I traced the wires down to two valves that were disconnected. The hydraulic lines from those valves head down into the bowels of the machine - I suspect down to the drive wheel motors, although I haven't taken any covers off of the lower unit yet. Does this sound reasonable? I'm assuming that the previous owner just used the machine in low travel gear all the time. Therefore, I may end up with problems with either the control valves or the drives. We'll see.
 
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