M925 M925A2 dump bed hoist install

[74M35A2]

Nice work. Adds a lot of functionality to an already fun truck.

 

[71DeuceAK]

Definitely. These trucks will go anywhere and do anything, but you made yours even more so!

 

[srodocker]

That is awesome. Exactly what I would like to do someday.

 

[Jbulach]

I forgot to post a very important step, if you use the trucks hydraulics to power anything other than a motor, you must vent the tank. I welded a 1/4" bung on the top of my tank, then used a shop vac on the outside and a little air pressure on the inside of the tank while I drilled the hole through. This prevents getting shavings in the tank. I then used 3/8"DOT tube and vented into an extra port in the intake stack, vent line, manifold.
Also make sure to get you system purged and the tank to the proper level before you connect the vent to the intake, to prevent pushing oil into your intake!

 

[farmerboywyotech]

So let's say you run a dump trailer that requires the reservoir is almost drained and refilled every time. How critical is the vent then and what issues would arise one way or the other

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[farmerboywyotech]

I don't have a picture of the hoist but it's a dual telescoping cylinder. I thought of an additional oil tank but I'm not sure where I'd put it and if it would have to be at the same level or if it could be higher like in place of the spare tire carrier since the 14.00 won't fit there.

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[Jbulach]

So let's say you run a dump trailer that requires the reservoir is almost drained and refilled every time. How critical is the vent then and what issues would arise one way or the other

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Without a vent you will rupture your tank or filter and possibly damage your pump.

 

[Jbulach]

I don't have a picture of the hoist but it's a dual telescoping cylinder. I thought of an additional oil tank but I'm not sure where I'd put it and if it would have to be at the same level or if it could be higher like in place of the spare tire carrier since the 14.00 won't fit there.

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Yes, you will most likely need more tank capacity for your type of cylinders. You could mount another tank higher, plumb it into the fill of the stock tank, then put your vent in the upper tank only.

Although driving on the ceiling is going to cause problems with vents!!!

 

[farmerboywyotech]

I only run the pump to raise once it's up I shut it off and let it gravity down and push the oil back in

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[Jbulach]

Heres the inlet pressure limits per EatonMaybe the engineering type here can calculate how much vacuum your pulling, or maybe you could rig a fitting up on the fill, so you can hook up a fuel pressure/vacuum gauge. If your displacing nearly the entire tank volume, I would be willing to bet your pulling more than 5" of mercury though.

 

[Jbulach]

Let me try thisThe path to the PDF is
www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pll_1409.pdf

Page 22


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[TedCat]

Awsome job, Im curious as to tank capacity.

 

[Jbulach]

Awsome job, Im curious as to tank capacity.

From overflowing to sucking air, right at 5 gallons. Fortunately the rods of my double acting cylinders only displace .85 gallon.

 

[Jbulach]

13-1/2 ton of sand, dumped facing uphill on about a 20 degree slope, about all the hoist wants at 2500 PSI.

 

[buggyman]

Looks GREAT
I want to install a hoist onto my 923, I've been thinking about the tailgate, maybe making a frame for the rear of the sides don't flex out; also pivoting the top of the tailgate to swing open on the bottom for some spreading abilities. How high are your sides and the front that you've added?
Thanks, Paul

 

[Jbulach]

A tailgate exactly like you describe is a little ways out on the todo list. I think I'm going to make a tube frame that drops in the back troop seat pockets and bolts through the existing tailgate chain slots.
I have 24" of wood on top of the drop sides, but 18" would be plenty for 13 ton of sand or gravel. The front is the head board off a deuce, with a packing blanket clamped over it for the time being. I think its around 18" tall.

 

[Jbulach]

Ok, here are some full articulation pictures for the Negative Nellies that think a scissors lift has to hit the intermediate axle... both tires on the rear axle hanging in the air.both intermediate axle bump-stops squished quite well.I forgot to bring a straight edge, but the airline spider on top of the axle is about flush with the top of the frame rail.The hoist to drive shaft clearance is close! If I would have had a longer stroke hoist, this point would be further forward and given more clearance. The driveshaft to air dryer crossmember is even closer, something to watch if you haul substantial weight or have damaged/missing bump-stops while traveling extreme off-road! Well, Negative Nellie maybe right in my case, looks like my cylinders hang down about a 1/2" below the frame rails, and make light contact with an air line. I may add a 1/2" spacer above the bump-stops to help this as well as assure clearance between the driveshaft and factory crossmember. I think there is some slack in my hoist pivots that I may be able to block up as well, it also looks like the air line spider could easily be modified for a lot more clearance.

 

[buggyman]

Thanks Jbulach for the reply. Putting your truck into the creak is a good test for articulation and clearance issues.
Did you put a wood floor into your bed?
Would you happen to know what your hoist is rated at?
Thanks again and happy trails
Paul

 

[Jbulach]

No, just the factory floor with a light coat of rust, streaked from dumping a load old shingles.


The only load chart I can find is a scanned PDF that is very hard to make out. The closest bed specs to what I have, I believe reads 16'-3" to 16'-5" platform length, with 29" of overhang is supposed to dump "liquid level load" of 24.6 tons at 45 degree dump angle. I'm not sure at what hydraulic pressure, but the two different original pump options where rated to 4 and 5kpsi and I found information on the supplied valve that is was preset to 3200psi, so I'm guessing 3200 is what these charts are based on? I am only running 2500psi for now, due to I'm using the winch control valve, which is only rated at 2500 max pressure, and I am dumping to 50 degrees.

 

[farmerboywyotech]

So your lift point is 126" from the hinge point?

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