Lull 944E-42 Service Manual Bedienungsanleitung PDF herunterladen (Seite 48)

Boom

3-18

944E-42

4. Measure the sag (1) in the top boom extend chain

between the bottom of the chain and the top of the

boom at their closest point. Acceptable boom chain

sag is between 3.0 in (76 mm) and 4.0 in (102 mm).

If the measurement is still less than 3.0 in (76 mm),

the boom chain needs to be adjusted.

If the measurement is either less than, or greater

than the range given, the boom chains need to

be adjusted. Continue with Section 3.4.6, “Boom

Chain Tension Adjustment” to adjust the chain

system.

5. Start the engine, retract the boom completely and

turn the engine OFF.

3.4.6 Boom Chain Tension Adjustment

Note: Always perform Section 3.4.5, “Boom Chain Ten-

sion Check” before adjusting the boom chain tension.

1. Park the machine on a hard, level surface, level the

machine, retract the boom, level the boom, place the

transmission control lever in (N) NEUTRAL, engage

the park brake and shut the engine OFF.

2. Remove the rear boom cover.

3. Adjust the extend chain by tightening or loosening

the retract chain adjustment nut on the front

underside of the first boom section.

4. If the chain sag measurement is less than 3.0 in

(76 mm), the retract chain adjustment nut needs to

be tightened.

If the chain sag measurement is more than 4.0 in

(102 mm), the retract chain adjustment nut needs to

be loosened.

5. Return to the cab, start the engine and cycle the

boom all the way out and all the way in several times.

6. Fully extend the boom, then retract it 2 in (51 mm)

Shut the engine OFF.

7. Measure the sag in the top boom extend chain

between the bottom of the chain and the top of the

second boom section at their closest point.

Acceptable boom sag is between 3.0 in (76 mm) and

4.0 in (102 mm). If the measurement is still less than

3.0 in (76 mm), the boom chain needs to be

readjusted.

Note: If all the adjustment has been used up on the

retract chain adjustment nut and the extend chain is not

within the acceptable sag range, the clevis at the top

front of the first boom section will need to be

repositioned.

8. Return to the cab, start the engine and fully retract

the boom. With the boom horizontal, extend the

boom out approximately 2 ft (610 mm) and shut the

engine OFF.

9. At the front underside of the first boom section,

loosen the retract chain adjustment nut. Back the nut

off until the top of the nut is flush with the end of the

threaded clevis.

10. Return to the cab. Have an assistant watch at the

front underside of the first boom section. Slowly

retract the boom until the retract chain adjustment

nut touches the clevis mounting tab on the underside

of the first boom section.

11. At the front top of the first boom section, move the

extend chain clevis to the next hole toward the rear

of the mounting plates. Coat the mounting pin and

bore hole with anti-seize compound and reinstall the

pin.

12. Return to the cab, start the engine and fully retract

the boom. Shut the engine OFF.

13. At the front underside of the first boom section,

tighten the retract chain adjustment nut to remove

the excess slack from the chains.

14. Make sure that the chain system is properly

tensioned. Refer to Section 3.4.5, “Boom Chain

Tension Check.”

15. Install the rear boom cover.

OA0493

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Lull 944E-42 Service Manual Bedienungsanleitung Seite 48

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