JLG 450A_AJ Series II Service Manual - Manual (Page 140)

SECTION 3 - CHASSIS & TURNTABLE
3-90 – JLG Lift – 3121180
3.11 SEMI-TRACK
The semi-track option is available in soft or hard tracks
and provides increased traction in rough terrain.
Testing
With both sides installed, drive machine slowly in both
directions to check track does not catch or hit any part of
machine. Test machine until it can be driven at top speed
and on side slopes without tracks hitting. Check track fre-
quently first few days after use that all bolts are tight and
no damage is being caused to tires or machine.
Removing
If tracks are muddy, wash or drive machine through water
before removing. If tracks will be stored in the laid out
position just as they come off machine, move machine to
storage area to remove tracks. If tracks are going to be
rolled up and put on a pallet, it is best to remove them on
a hard surface. Remove bolts that hold track together.
These bolts are accessible over the front tires. After nuts
are removed, pound them flush with pad. Drive machine
ahead until bolts are at the bottom between tires. Remove
inside bolts by turning them out with a wrench and punch
out the outside bolts. Drive machine ahead and take off
tracks. If track is to be rolled up, set track on edge and roll
it. Secure end of track and put loose hardware in end of
track.
Normal Wear
It is normal for the bushing to wear down to the bolt and
for the link hole to wear oblong until it is ready to break out
the end.
Adjustment
IMPROPER SLACK ADJUSTMENT CAN CAUSE TRACK PARTS TO
BREAK.
Place a straight edge long enough to reach from idler to
drive wheel on the tracks. Measure maximum amount of
track sag from high point of track segment to bottom of
straight edge. Properly adjusted track will have 1 to 2
inches (25 to 50 mm) slack. (See Figure 3-57.)
To adjust the slack measurement, move bolts from first
hole to the second to create less slack, or from to second
to the first to create more slack.
Table 3-12.Adjustment Chart
Move 1 Hole 2 Holes 3 Holes 4 Holes 5 Holes 6 Holes 7 Holes 8 Holes 9 Holes 10 Holes 11 Holes 12 Holes
Equals 0.81 in
(20.5 mm)
1.62 in
(41 mm)
2.43 in
(62 mm)
3.25 in
(82.5 mm)
4.06 in
(103 mm)
4.87 in
(124 mm)
5.68 in
(144 mm)
6.50 in
(165 mm)
7.31 in
(186 mm)
8.12 in
(206 mm)
8.93 in
(227 mm)
9.75 in
(248 mm)