M1084/M1086 MATERIAL HANDLING CRANE (MHC)

TM 9-2320-366-20-1

1-18. M1084/M1086 MATERIAL HANDLING CRANE (MHC)

Figure 1-27. M1084/M1086 Material Handling Crane (MHC)

Vehicle models M1084 and M1086 are equipped with a Material Handling Crane (MHC) (1, Figure 1-27) mounted on

the frame at the rear of the vehicle. The M1084/M1086 MHC has a lifting capacity of 5,000 lbs (2,270 kgs). The MHC

contains an overload shutdown system which monitors boom angle, boom extension, and load weight. If the overload

shutdown system senses an overload condition, certain crane functions become locked out. The vehicle is stabilized

during crane operation by jack cylinders (2). Proximity sensors are attached to the jack cylinders to prevent operation

of the crane unless the jack cylinders are extended to the ground. Outrigger pads (3) are provided and are attached

to the bottom of the jack cylinders by quick release pins. All crane functions are hydraulically controlled by levers at

the control station (4). All exposed hydraulic cylinder rods are hard chrome plated to resist corrosion and wear.

a. MHC Hydraulic System. The hydraulic reservoir (5) provides for 21 gal (79 L) of fluid. A fluid filter (6) is mounted

on the hydraulic reservoir. The filter removes contaminants from the oil and is easily replaced. Hydraulic pressure for

the MHC is supplied by a hydraulic pump (7) attched to the rear of the Power Take-Off (PTO) (8). The hydraulic

cylinders contain cartridge-type holding valves which lock the cylinder in case of sudden hydraulic pressure loss. A hand

operated back-up hydraulic pump (9) allows the operator to lower any load to the ground and stow the crane if the

hydraulic pump fails.