TRUCK SERVICE MANUAL
SPEEDOMETER, TACHOMETER AND CABLE TROUBLE SHOOTING
Disconnect upper end of speedometer or tachometer
cable by removing four mounting screws from
instrument cluster and detaching cluster enough to
expose back of cluster.
Depress spring clasp on back of speedometer or
tachometer and release cable (Fig. 4).
Unscrew cable lower or drive end from adapter at
either transmission or engine component.
Unfasten cable from any ties or clips and remove
complete cable assembly from chassis.
Pull the flexible core out of case and check for kinks by
rolling core on a flat surface.
A core kink will show up as a hop at kinked point.
Check for frayed spots by running core loosely through
Repair or Replace Core
Never reuse a kinked or frayed core. A kinked core will
cause a fluctuation of speedometer or tachometer reading and a
frayed core will fail completely a short time after being returned
If replacement core is used, be sure core is not
too long. A long core will cause a damaging
thrust to head of speedometer or tachometer
Apply a thin coat of lubricant (IH #251H EP) to core at
reassembly as follows:
Place approximately 1 teaspoon of lube in one hand.
CTS-2735 Page 8
PRINTED IN UNITED STATES OF AMERICA