
146
Maintenance Section (D6T LGP (OEM)) WEBM1000
Front Idler Position - Check
a. (A) Front Idlers
Minimum – 0 mm (0 inch)
Maximu
m – 2
0 mm (0.8 inch)
b. (B) Rear Idlers
Minim
um – 10 mm (0.4 inch)
Maximu
m – 4
0 mm (1.6 inch)
4. Repeat Steps 1 thro
ugh 3 in order to determine
the proper height dimension under each idler.
189
Illustration 189
Adjustment shim (center tread idler)
5. For machines with the SystemOne
Undercarriage, remove one shim under each
track idler block when the wear on the link and
roller system is at 50%.
Consult your Caterpillar dealer
for detailed
infor
mation about adjustments to the center tread
idler.
See Operation and Maintenance Manual, “Track -
Che
ck/Adjust” f
or information on needed track
adjustments.
Reference: S
ee Oper
ation and Maintenance
Manual, “Reference Material” for publications and
Special Instructions, on removal and installation of
SystemOne Track, as needed.
Conventional Design
190
Illustration 190
(A) Adjusting shims
(B) Dimension between the height of the front idler tread and the
height of the roller tread
The following check is for undercarriage systems
that have the conventional idler.
The height of the front idler tread should always
be hi
gher than the height of the roller tread. The
dimension (B) is set approximately to 9.0 mm (.35
inch) at the factory. Dimension (B) decreases as the
undercarriage wears. If a rebuilt idler or a new idler
is installed with track rollers that are worn, dimension
(B) decreases.
Adjustment of the front idler to the correct height can
imp
rove
the ride of the tractor and the performance
of the dozer. Use the following procedures to
determine the best operating position.
If the machine is operated on FIRM UNDERFOOT
co
nditions
and excess vibration occurs, shims can
be removed in order to raise the front idler.
If the machine is operated on SOFT UNDERFOOT
co
nditions
and dozing performance is poor, shims
can be installed in order to lower the front idler.
Lowering the front idler can improve dozing
performance. If ground rippling by the dozer or
excess vibration occur in soft material, shims can be
removed in order to raise the front idler.
Consult your Caterpillar
dealer for detailed
infor
mation about checking the idler and about
adjustments to the idler.