JLG sky trak mmv Service Manual page 82

General Information, Specifications and Maintenance
9. Start the vehicle, cycle the boom in and out several
times. With the boom horizontal, fully extend the
boom and then retract it 2" (51 mm) (one inch per
section). Turn the engine OFF.
1
10. Measure the sag (1) in the top extend chains
between the bottom of the chains and the top of the
intermediate boom (2) at their closest point.
Acceptable boom chain sag is between 1.5-2.5"
(38-64 mm). If the measurement is less than 1.5"
(38 mm), the top boom extend chains may need to
be adjusted. (Refer to Section 2.13.21, b. Extend
Chain Adjustment .)
b. Extend Chain Adjustment
Note: Always perform the "Boom Chain Tension Check"
Refer to Section 2.13.21, a. Boom Chain Tension Check,
before adjusting the boom chain tension.
1. Park the vehicle on level ground. Place the travel
select lever in the [N] NEUTRAL position, place the
neutral lock lever in the [N] NEUTRAL LOCK
position, engage the parking brake switch and raise
the boom to a horizontal boom. Retract the boom
completely and turn the engine OFF.
2.66
2. Adjust the top extend boom chains by tightening the
locknuts (3), located at the rear of the boom (4). Be
sure each locknut is tightened equally, so that each
chain maintains the same tension.
3
2
OA0491
3. Equal boom extend chain (5) tension can be
checked by the position of the yoke (6) on the outer
boom. The front of the yoke should be parallel with
the front of the front edge of the outer boom.
4
5
Model MMV Rev. 12/04
3
OT05002
6
OT07702