The JLG 40F Boom Lift Dilemma

[ATCOEQUIP]

Originally Posted by od1

Man that’s amazing. That’s great to know.
I’ll have to reread everything again. I don’t remember talking about that before.
How fast do you think I can roll with it? Is there a hitch plan anywhere for it?
There seems to be a setup for it on the front side (non drive side).

Thanks again for all of your input ATCO. It’s a huge help.

Don't get too exited, disconnecting the hubs is the easy part, towing it is a problem in itself. JLG had a "tow option" on these machines that consisted of a rigid tow bar that connected to the steer axle frame and had a tie rod that went to the steer wheel opposite the steer cylinder. If you don't have this tow option, then you problems begin there. First, you can't tow it with a chain/tow strap because the machine has the brakes disconnected. You have to use a rigid tow bar. Easy enough...make one. But, you still have the problem with the steer axle. The steer wheels have to be able to move as the tow vehicle rounds corners and bends in the road. There's one thing we need to determine at this point. On a number of 40F machines, JLG installed a diverter valve for the steer cylinder even if the machine didn't have the tow package. If I remember, the diverter valve was located directly behind the engine, below the boom mounting. You could raise the side panels and see the diverter valve with a knob on it near the center of the machine behind the engine. Does you machine have this diverter valve?

[OFF]

Originally Posted by od1

Man that’s amazing. That’s great to know.
I’ll have to reread everything again. I don’t remember talking about that before.
How fast do you think I can roll with it? Is there a hitch plan anywhere for it?
There seems to be a setup for it on the front side (non drive side).

Thanks again for all of your input ATCO. It’s a huge help.

We had a tow bar made up for 40F's back in the day. It was basicly a "U" channel welded to a piece of pipe with a hitch on the oposite end.
In the center of you steer axle there's a pivot. The U-channel fit around the sides of pivot, a bolt slipped through the "U" and that was it. You can always disconnect one or both sides of your steer cylinder when you tow.

As for your brakes, like ATCO said when that block contacts the body of the cylinder you're out of adjustment. I remember the brakes on 40F's never being really great. I was always tinkering with them. Most manlifts use an internal wet multi-disc system that works so much better. I'd be interested to see if that 42C you had in your sights used an internal brake. I know the 50F and 60F did.

[od1]

Originally Posted by ATCOEQUIP

Don't get too exited, disconnecting the hubs is the easy part, towing it is a problem in itself. JLG had a "tow option" on these machines that consisted of a rigid tow bar that connected to the steer axle frame and had a tie rod that went to the steer wheel opposite the steer cylinder. If you don't have this tow option, then you problems begin there. First, you can't tow it with a chain/tow strap because the machine has the brakes disconnected. You have to use a rigid tow bar. Easy enough...make one. But, you still have the problem with the steer axle. The steer wheels have to be able to move as the tow vehicle rounds corners and bends in the road. There's one thing we need to determine at this point. On a number of 40F machines, JLG installed a diverter valve for the steer cylinder even if the machine didn't have the tow package. If I remember, the diverter valve was located directly behind the engine, below the boom mounting. You could raise the side panels and see the diverter valve with a knob on it near the center of the machine behind the engine. Does you machine have this diverter valve?

I just went to look, and I’m not sure what I’m looking for. Behind the engine on the right there is a bracket with a line coming out but I’m not sure if that’s the 1 you mean.
Where does the line run to?
In the front before the steering cylinder there is a bracket which looks factory for a towbar.

[od1]

Originally Posted by OFF

We had a tow bar made up for 40F's back in the day. It was basicly a "U" channel welded to a piece of pipe with a hitch on the oposite end.
In the center of you steer axle there's a pivot. The U-channel fit around the sides of pivot, a bolt slipped through the "U" and that was it. You can always disconnect one or both sides of your steer cylinder when you tow.

As for your brakes, like ATCO said when that block contacts the body of the cylinder you're out of adjustment. I remember the brakes on 40F's never being really great. I was always tinkering with them. Most manlifts use an internal wet multi-disc system that works so much better. I'd be interested to see if that 42C you had in your sights used an internal brake. I know the 50F and 60F did.

The second thing I was worried about was the steering cylinder. I thought if I disconnected it the rig would then be too unmanageable to tow. It would react like a hay wagon on a hitch bar, you know drifting from side to side. This would force a pickup truck all over the road. Pretty dangerous. What do you think?
I’m still a little lost on the brake thing. I think it’ll be clearer for me once I start playing with it.

[od1]

As for the 42C I didn't bid on it. The auction was a joke. If I'm going to get another one I think it'll be better for my business to have a 4 wheel drive rig. I could maybe use it for de-limbing plantation trees. There's good money in poles.

[OFF]

Originally Posted by od1

The second thing I was worried about was the steering cylinder. I thought if I disconnected it the rig would then be too unmanageable to tow. It would react like a hay wagon on a hitch bar, you know drifting from side to side. This would force a pickup truck all over the road. Pretty dangerous. What do you think?
I’m still a little lost on the brake thing. I think it’ll be clearer for me once I start playing with it.

You shouldn't be going fast enough that side to side would become a problem, but yes it would steer like a farm wagon. The side to side you mentioned is from the steering parts of a wagon being worn right out. New wagons don't do that dance. It won't follow at all with the cylinder the way it is. You'll turn a corner and the manlift will keep going straight.

Take the cylinder apart and see which way the springs act. Either the springs "pull" and you're out of adjustment, or the springs are ment to push and they're all broken. (the wavy washers I mentioned)

[od1]

If it warms up tomorrow I'll remove it. Do you know how thick the new pads are supposed to be? While I have it apart I'll give it to my friend to re-line.
Thanks again for all of your help on this.
Talk with you soon.

[ATCOEQUIP]

Originally Posted by od1

I just went to look, and I’m not sure what I’m looking for. Behind the engine on the right there is a bracket with a line coming out but I’m not sure if that’s the 1 you mean.
Where does the line run to?
In the front before the steering cylinder there is a bracket which looks factory for a towbar.

If I remember correctly, the steering diverter valve was located inside the engine compartment, in the area of and the hyd pump. It would look similar to, but not exactly, the first valve shown in link below;

http://www.baileynet.com/index.php?i...tegory=1000032


Can you send a pic of the steer cylinder showing the steer links and bracket that you mentioned?

[od1]

Thanks ATCO
I checked out that link, and there is nothing like that on this 40F. Is it's use to cut fluid to the drive motors? If so can I retro-fit this on my rig?

[od1]

Look below the steering cylinder, and towards the middle. You’ll see a vertical part protruding with a hole. I think that’s for the hitch bar.

[flhayman]

I stumbled upon this by accident. I have a 40F that I would like to sell. I have been afraid to try, since it doesn't have OSHA safety inspections, etc. and requires some operator knowledge. Here are people that know about this machine! Overall good condition, I think. Brakes work, all switches work on the platform, horn relay works, but I never replaced the horn. Replacement solenoid for low/high engine speed in hand, but not installed yet. Was originally proportional Racine, but had a leaky part, nobody locally knew how to fix it, so I bought a new block and put 4 solenoid operated valves and a variable restrictor on, also put a filter on the return side. Have the Racine valve bank and controllers to give to the buyer, also. 1 new drive tire, bunch of new hoses, power track is freed up on every link, doesn't bind up and bend anything. Platform rotate has hoses run, but was spot welded in a fixed position by previous owner, but has an extra valve to operate it, plumbed to the rotator, (must have had a leak at the rotator motor? or had coil problem? don't know).

I do have some wiring diagrams, bought from JLG, that are probably the same as the other helpful posters have. I blew mine up to 200% size and laminated them for working outside with the wiring. I agree with the previous poster that said it is a very well built lift, it is tight and strong, with no hint of instability while you are up in the air with it.

[od1]

Why are you selling it?

[ATCOEQUIP]

Originally Posted by od1

Thanks ATCO
I checked out that link, and there is nothing like that on this 40F. Is it's use to cut fluid to the drive motors? If so can I retro-fit this on my rig?

The diverter valve I was hoping would be on yours is to allow steer cylinder to move while your towing the machine. If you don't have the valve, no big deal, just do what off suggested by disconnecting the steer cylinder where the rod end connects to steering knuckle, retract the cylinder, then swing it away from the steering components so you can tow the machine.

Yes, the bracket in the pic is for connecting tow bar. Just build a tow bar with a pintle hitch ring to hook to tow vehicle, disconnect steer cylinder, turn over the plates on the drive hubs, and your ready to tow. Just go slow because your still turning plantery gears in the drive wheel Torque Hubs.

[flhayman]

Originally Posted by od1

Why are you selling it?

I've got some really tall trees, and was hoping to get a 60 or a 66 foot one. It has really been handy to have. I could use 4wd for a few places, but by watching the angle I approach ridges or valleys, it's doable. I wonder, though, what the tire loading on my asphalt driveway would be with one of those bigger machines, whether it would instantly crack it.