Hitachi ZAXIS 120-3 class, Operator'S Manual, Page: 268 / 461

MAINTENANCE
7-77
8
Check Track Sag --- every 50 hours
Swing the upperstructure 90° and lower the bucket to raise
the track off the ground as shown.
Keep the angle between the boom and arm 90 to 110°
and position the bucket’s round side on the ground. Place
blocks under the machine frame to support the machine.
Rotate the raised track in reverse two full rotations and then
forward two full rotations.
Measure distance (A) at the middle of the track frame from
the bottom of the track frame to the back face of the track
shoe.
Track sag specifications
Model A
ZX120-3 Class
(Except ZX110M-3)
250 to 280 mm
(9.8 to 11.0 in)
ZX110M-3
265 to 295 mm
(10.4 to 11.6 in)
ZX160LC-3
285 to 320 mm
(11.2 to 12.6 in)
ZX180LC-3, 180LCN-3
ZX200-3, 270-3 Class
(Except ZX280LC-3, 280LCN-3)
300 to 335 mm
(11.8 to 13.2 in)
ZX280LC-3, 280LCN-3
ZX330-3 Class
340 to 380 mm
(13.4 to 15.0 in)
NOTE: Check track sag after thoroughly removing soil stuck
on the track area by washing.
Adjust Track Sag
Precautions for Adjusting Track Sag
1. If track sag is not within specifications, loosen or tighten
the track following the procedures shown on the next
page.
2. When adjusting track sag, lower the bucket to the ground
to raise one track off the ground.
Repeat this procedure to raise the other track.
Each time, be sure to place blocks under the machine
frame to support the machine.
3. After adjusting track sag of both tracks, move the ma-
chine back and forth several times.
4. Check track sag again. If track sag is not within specifica-
tions, repeat adjustment until correct sag is obtained.
SA-283
M107-07-068