Loader Backhoe

The loader backhoe tractor (fig. 9-41) is equipped with a 1.3-cubic-yard bucket mounted on the front and the backhoe mounted on the rear.

The loader is equipped with a four-speed transaxle that permits the gears to be shifted from first or second to third or fourth and back again to third without stopping. When shifting gears, always make sure the engine speed remains in the green area of the tachometer.

The loader also has a differential lock that gives equal power to both rear wheels when the machine is stuck or before the loader is operated through a soft or muddy area. When the loader is stuck, the differential lock is actuated as follows:

1. Make sure the rear wheels are not turning.

^2. Push down the clutch cutout pedal (fig. 9-42).

3. Push down the differential lock pedal.

^4. Release the clutch cutout pedal.

5. Increase the engine speed and release the differential lock pedal.

NOTE: The differential lock releases automatically when the load is removed.

Figure _9-41 .-Loader backhoe.

Before operating through a soft or muddy area, you can actuate the differential lock as follows:

1. Before moving the loader through an area that is soft or muddy, make sure that the loader is moving in a straight direction and that one of the rear wheels is not rotating faster than the other rear wheel.

2. Push down the differential lock pedal while the loader is moving through the soft or muddy area.

3. After the loader has moved through the area, release the differential lock pedal.

NOTE: Engaging the differential lock when the loader is turning or if one rear wheel is rotating faster than the other wheel can cause damage to the transaxle.

When servicing the engine with the loader lift arms raised, always use the support strut (fig. 9-43).

The procedure for attaching the support strut is as follows:

1. Empty the loader bucket and raise the loader lift arms to the maximum height and stop the engine.

2. Remove the rear pin from the support strut and lower the strut onto the cylinder rod.

Figure _{9-42.-Transaxle controls.}

Figure 9-43.-Support strut.

Figure ^{9-44.-Swing lockpin.}

Figure 9-45.-Use handrails and steps to climb into the operator's seat.

Figure 9-46.-Lower the bucket to raise the front wheels a few inches above the ground.

Figure 9-47.-Rotate the operator's seat and increase the engine throttle.

_3. Install the rear pin in the support strut.

^4. Slowly lower the lift arms onto the support strut.

WARNING

Failure to use the support strut when servicing the engine can result in serious injury or death if the loader arms are lowered by accident.

Backhoe operation is as follows:

1. Removed the swing lockpin (fig. 9-44).

2. Climb into the loader using handrails and steps (fig. 9-45).

3. Rotate the loader bucket into the dump position _{and lower it to the ground. Lower the bucket until} front wheels are a few inches above the ground (fig. 9-46).

Figure 9-48.-Lower the stabilizers to raise and level the theloader.

4. Rotate the operator's seat to the rear of the loader for backhoe operation and increase the engine speed to full throttle (fig. 9-47).

5. Lower the stabilizers and raise and level the loader (fig. 9-48).

6. To release the boom latch, push the boom latch control lever to the left and hold it until the boom is released (fig. 9-49).

7. Extend the boom and bucket to start digging operations, as shown in figure 9-50.

8. To dig with the backhoe, move the dipper stick inward and fill the bucket (fig. 9-51, view A). Once the bucket is filled, curl the bucket inward (fig. 9-51, view B). Swing the boom and dump the material from the bucket (fig. 9-51, view C). Return to the trench and lower the bucket (fig. 9-51, view D).

Figure ^{9-49.-Release the boom latch.}

Figure 9-50.-Bucket and boom in position for digging operations.

Figure ^{9-51 .-Digging With the backhoe.}

Figure 9-52.-Backhoe bucket adjustment digging positions.

Figure _9-53.-Track-mounted excavator.

The backhoe bucket can be adjusted for two _digging positions. The position for loading dump trucks is shown in figure 9-52, view A. The position for digging deep, vertical holes is shown in figure 9-52, view B.

The backhoe can dig more material in less time when a smooth, short dig cycle is used. When the bucket is forced to excavate a load that is too large (when the dipper stick control lever is pulled back and the bucket is not moving), a "hydraulic stall" results in the loader hydraulic system. When this occurs, the main relief valve of the hydraulic system makes a noise, alerting the operator to release the control lever.

NOTE: Hydraulic stalls cause the temperature of the hydraulic fluid to increase that can cause premature wear to the hydraulic system.