Check Track Sag - Hitachi Zaxis 850LC-3 Operator's Manual

7 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
ZAXIS850
-3
ZAXIS870H
-3
ZAXIS850LC
-3
ZAXIS870LCH
-3
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.
A
400 to 500 mm (15.7 to 19.7 in)
470 to 530 mm (18.5 to 20.9 in)
MAINTENANCE
7-85
M104-07-067
M107-07-068