Lull 644E-42 Operation Manual - Manual (Page 151)

General Maintenance
149 Model 644E Origin 3/04
A. Boom Chain Tension
Check
(250 Hour Intervals)
Check the boom chain tension by measuring the top boom extend chain sag.
NOTE: The attachment should remain attached to the quick attach for these checks.
1. Park the vehicle on level ground. Place the travel select lever in the (N)
NEUTRAL DETENT position, engage the parking brake switch and raise
the boom to a horizontal (level) position.
2. Fully extend the boom, then retract it 2" (51 mm) (one inch per section).
Turn the vehicle OFF.
3. Measure the sag (6) in the top boom extend chain (7) between the bottom
of the chain and the top of the intermediate boom (8) at their closest point
(6). Acceptable boom chain sag is between 3.00" (76 mm) and 4.00"
(102 mm). If the measurement is less than 3.00" (76 mm) or more than
4.00" (102 mm), the boom chain needs to be adjusted. Refer to the ìBoom
Chain Tension Adjustmentî to adjust the chain.
18. Boom Chains and Wear Pads
OU0840
250
OH2710
OA0491
6
7
8