Crane Base Reinforcement

[319]

Finally was able to install (photo is before cleaning and painting) my crane in the bed of my M35A2. This thing has a 2000lb capacity, not that I'll use it to lift that much, but was wondering how others have reinforced theirs below the bed. I did a search and only found one mention (by ARMYMAN30YearsPlus, God rest his soul) but the link is no longer good. Can anyone post pictures of their installation or advise the best way to reinforce the bed so I don’t bend it while lifting.
The base of the crane straddles the mud flap support, and my thoughts were to use either ½” steel plate or ¼” x 3” steel channel.

 

[maddawg308]

Can anyone post pictures of their installation or advise the best way to reinforce the bed so I don’t bend it while lifting.
The base of the crane straddles the mud flap support, and my thoughts were to use either ½” steel plate or ¼” x 3” steel channel.

I don't have any pictures, but if I were you, try finding some heavy steel, about 1/2 inch to 1-inch thick, and cut smaller pieces out of it. Make a panel as big as you can fit underneath the bed in the general area of where the crane is mounted, and bolt it to those four bolts you see there. Make sure that the bolts go all the way through, from the top of the base of the crane, through the bed and to the bottom of the heavy plate. Snug it up, and I doubt you will have any problems bending the bed, or pulling the bolts through the floor.

 

[gimpyrobb]

Looks like it would be easy enough to cut that mount off, slide a plate in there, bolt the crane down, and then weld the mudflap mount to the plate. The more surface area you have, the better. I think 1/4 plate would be good overkill.

 

[blybrook]

If you don't want to mess with the mud flap mount, build a support frame with 1/4" angle (minimum thickness) and the 1/4" plate.

Use the angle directly between the lock washers and the bed for each set of two bolts (two angles total) with the vertical legs towards each other. Then take your 1/4" plate and weld it to the ends of the vertical legs. This will allow you to remove it without too much issue and give a better lateral / bending restraint than plate alone.

Based on your pictures, I'd go with 3x2x1/4 angle, 3" longer than the bolt spacing (1-1/2" minimum from edge to bolt hole center); long leg horizontal (on the bed) with bolts centered in angle. It looks like the flap angle is 2" vertical, but you can adjust your angle to match that dimension as necessary. Then add your plate.

If you need it drawn up, I can sketch something later and post it up as a PDF.

 

[319]

Mike, my intention is to use 1-1/2" or 2" Gr8 bolts anticipating using 1/2" plate. The base of the crane is either 3/8 or 1/2" and the bolts will go all the way through.

Chris, that was my first though and probably the best solution and am leaning in that direction, but I'd rather not cut the truck if I don't have to. I also thought of taking the plate and cutting a slot out of it to fit over/around that bracket.

 

[gimpyrobb]

Never thought about that. I bet a band saw would make a good slot, or even an angle grinder.

 

[MikeON]

Whichever of the above suggestions you use, you want to tie the reinforcement in with the end cross member of the bed (the heavy tapered channel). This will take most of the bending off the bed plate itself.

Another suggestion would be to weld a plate to the bottom of the crane mount (above the bed) long enough to reach from the rear cross member to the next cross member forward, and then bolt it through the bed to the cross members.

 

[319]

Thanks for the suggestions. I'm going to ponder this situation and kick a few of these ideas around.
I'll post some pictures of the finished product.

 

[SCSG-G4]

I purchased a divot crane kit and it came with the long pieces of angle iron to put underneath the bed.

 

[Jones]

When I built the spare tire crane for the baby HEMTT, this is how I strengthened the mount. The plate runs from the tie-in at the pass. side frame sub-rail frame to the outside edge of the bed and from the sheet-metal 'apron' under the headboard to the front face of the first bed crossmember.
Hope the picture will give you an idea or two.
The secret is to have as large a footprint under the bed floor as is possible. Flat washers will eventually pull through as they don't spread the load like a piece of plate, or angle or channel-iron runners will. Figure what direction most of your lifts will be and run the stiffeners so that you get maximum support in that direction.

 

[Westex]

From the picture I see, don't use 1/4 inch plate, use 1/2 inch plate. Why mickey mouse it.

 

[Jones]

The crane base looks like it's at least 1/4" plate. Add that to the thickness of the channel or angle iron or plate under-floor reinforcement and the floor sheetmetal and you've hit 1/2" thickness total.
My own set-up is decked with 1/4" diamond plate + floor sheet thickness + 1/4" under floor stiffener with it's folded edges that bolt to surrounding braces, bed edge, and headboard apron-- not exactly what I'd call 'mickey mouse'.

 

[319]

Okay folks, here is how I did it. I used a 1/4" X 12" X 36" plate on top, fastened through the floor to the three aft bed ribs with 1/4"-28 Gr 8 HHCS, and two 5" X 2-1/2" steel channels below the bed fastened through the base and bed with 1/2"-20 Gr 8 HHCS. This should distribute the weight pretty good and not flex or damage the bed.
All that's left to do now is to find time to install the winch.

 

[blybrook]

Nice, clean install. Good job. Looks like it'll last a long time.

 

[swbradley1]

Looks good Eric. Having seen your work on bobbing 818s I expected nothing less.

I guess you didn't want to lift any more HEMTT rims into the truck by hand.



steve

 

[gimpyrobb]

Is that the rig you are bringing to Haspin? I have been thinking of putting a crane on my truck for a long time.

 

[319]

Is that the rig you are bringing to Haspin? I have been thinking of putting a crane on my truck for a long time.

If I make it to Haspin it will be in the M1009. Fuel costs for the M35 will deplete my children's inheritance faster than either I or they want!



Thanks for the compilments all.

 

[tm america]

Get free waist oil and a trip to haspin is free. Nice job . What do you do when you want to use the troop seats?

 

[319]

Get free waist oil and a trip to haspin is free. Nice job . What do you do when you want to use the troop seats?

Hadn't thought of the waste oil and have not used any to date, I'll kick it around.

Crane comes out of the base and base is shorter than the bottom of the seats, so no problem.

 

[tm america]

ok cool. i run mine on a 50/50 mix most of the time it is what they are made for . Just make sure you filter it first your filters will thank you .I run my waist oil through a 10 micron filter first .. It is really nice to have a truck you can drive for free i dont think you can say that about any other vehicle on the road