mounting a knuckleboom crane

Lance ask me to post about mounting a knuckleboom crane. So I'll write a little on the subject.


HI Lance, or anyone interested,

What I did to mount a knuckleboom crane:

My truck was originally a M49 which happens to be a standard length M35 truck.

I removed the M49 fuel tank from the rear and located the bed from an M342A2 dump truck. This bed is shorter than a standard cargo truck bed. This left me with ~2 ft of space between the front of the bed and the back of the cab. Instead of mounting the tool box and spare tire in this space as is done on the M342's, I removed the cab shield from the dump bed and mounted the crane from an Alvis Stalwart. That is a British military truck. It is used for loading ammunition. Most knucklebom cranes for this class of truck take up about 2ft of frame length, so this method of swapping beds should work.

Other difficulties I encountered were:

The crane legs ended up right where the truck fuel tank and spare tire were mounted. I solved this problem by using a set of smaller diameter tanks from an M275 tractor truck and shortening them to fit in the space available. I now have a 35 gallon tank on each side.

The rear frame cross member on the M342 is also mounted forward to allow clearance for the hitch. Otherwise the pintle hitch will be bent down when the truck bed dumps (don't ask me how I know this!) I solved this by reversing the rear cross member channel and remounting the pintle hitch inside the channel. There is also a rear cross member angle brace I had to move forward a few inches to match the new cross member position.

The dump bed hydraulic pump is mounded between the frame rails behind the transfer case and powered by the rear facing PTO adapter mounted on the transmission PTO.

The crane is powered by the rear facing PTO on the transfer case. This attachment is standard on the fuel tanker truck so I already had the linkage to operate it.

another difficulty is the dump bed PTO lever and transfer case PTO lever are both mounted on the left of the drivers seat using the same linkage shaft mounted across the floor of the cab behind the drivers seat. I solved this problem by exchanging the solid shaft behind the drivers seat with a tube exactly the same size. Then I ran a shaft through the tube allowing the attachment of the original linkage end and lever on the outside of the tube and the extra set of linkage end & lever on the ends of the smaller inside shaft. This way both PTO control levers fit nicely to the left of the drivers seat.

Another little known fact is; If the transfer case has a PTO, you should never leave the transfer case in neutral and the transmission in gear (unless the transfer case PTO is also engaged) or the upper bearings in the transfer case will not be adequately lubricated.

I'll attach a couple of photos of the crane in action. I took the truck to work to unload a large silencer (muffler) for the caterpillar engines I run at the power plant. They delivered it in a box truck and I had to reach in and pick it up, then the truck driver drove out from under it. It was so long there was no way to unload it with a forklift.


Bill
Michigan

Bill, that is one of the most beautiful trucks I have ever seen! The Strata Blue really make the truck stand out, and your hard work in its modification makes it all the more impressive.

Thanks Mike,

I just got it running again with an engine swap, I also finally built a set of dump bed side racks and installed a canvas top on the rear. I am now working on the front side rack for the dump bed and thinking about end curtains. I'll probably have to have some custom made.

I'll have to get some more recent photos and post them.

Bill
Michigan

Those lift cylinders on the crane look pretty beefy in diameter. What are its capacities and reach? Again, very sick truck.

Still have the M342 spare tire carrier?

Sorry, I never had the tire carrier or tool box. And after asking around I scrapped the cab shield.

Bill
Michigan

Hi Bill,
That's a really nice truck... just a quick question, were you Power Pro in the Air Force? I ask since you are working on Cat power plants. I was Power Pro for almost 10 years before I got out.

Later,
Joe

No, Not "power pro". I worked on KC135's, 455X2B Communications & Navigation Systems Technician. I now run Cat3516's at a CO-Gen power plant in Michigan.

The crane capacity close up is ~ 7000lbs and all the way out ~13ft is about 3000LBS.

The cylinder operating pressure is 3000lbs

I would like to get a jeep, mule, or mighty mite to carry around in the back.

I wonder what a Jeep weighs?



Bill
Michigan

miltruckman said:

.......
I would like to get a jeep, mule, or mighty mite to carry around in the back.

I wonder what a Jeep weighs?.....

Click to expand...

This is what it looks like with a jeep on the back...

man thats a nice truck thats the same idea i was talking to offroad about i think we need to talk i've got some questions to ask you.

Bill, thanks for the reply. I'll probably need to read it about three times for all of it to sink in.

Any idea where to find a similar crane?

Has anyone mounted a crane on a 5 ton and used Deuce bed behind it?

Lance

Joe, Cranetruck has been here forever (nothing negative Cranetruck) do a search.

Bjorn, funny how we both started out with an M49 Fuel truck.

Looks like your crane is a bit larger than the one on my truck. I ended up building an extension for mine to get some more reach. I have been eying the small log grapples on eBay, but that is another project.

I was also looking at the marker lights you have mounted on the sides of your truck, front & rear, and the light bar above the cab. Was that your own design or is there a kit that does that?

Lance,

I always thought the ultimate crane truck would to be to take the folding crane off of one of those Oshkosh self loading trailer/truck rear ends I see for sale on G.L. occasionally and mounting it on a 5 ton truck. I also see knuckleboom cranes for sale on Ebay once in a while. Sometimes quite cheap too.

miltruckman said:

Bjorn, funny how we both started out with an M49 Fuel truck.

Looks like your crane is a bit larger than the one on my truck. I ended up building an extension for mine to get some more reach. I have been eying the small log grapples on eBay, but that is another project.

I was also looking at the marker lights you have mounted on the sides of your truck, front & rear, and the light bar above the cab. Was that your own design or is there a kit that does that?........

Click to expand...

Examples of boom extensions shown here, the first one is simply a wooden one made on site and the second one is a rectangular tubing with flat stock welded on to its side for strength. Reach was extended to about 38 ft.
Crane is classified as 8 ton-meter, so 1 meter out it can lift 8 tons, 2 meters out 4 tons, 4 meters out 2 tons etc.
Outriggers extend to a total of 12 feet apart and will easily lift the entire 17,000 lb vehicle ( I never needed a jack).

All extra lights are "homemade".

The M49A2C is a good starting point, since it comes with the transfer case PTO.

www.transporttech.net This guy imports K-Booms of all kinds and sizes.

very nice, now i want one.