PREVENTIVE MAINTENANCE TRANSMISSION AND CLUTCH
Regional Haul
(R05/10) Y53-6033 – 237 –
As the clutch pedal is depressed further, with harder pres-
sure, the release yoke moves the release bearing away
from the engine. This causes the clutch plate to release
from the driven disks in the clutch. This is called release
travel. And finally, on 9-, 10-, and 11-speed transmis-
sions, as the pedal is pushed to the last 1/2 to 1 inch of
travel, the release bearing contacts and engages the
clutch brake. This is called clutch brake squeeze. When
the clutch wears, the release bearing gradually moves
toward the engine, decreasing free pedal and free travel.
When all free pedal and free travel are gone, the clutch
requires adjustment.
The clutch is adjusted by turning an adjustment ring that is
built into the clutch. When the ring is turned, the release
bearing moves back toward the transmission, restoring
free pedal and clutch free travel. Under normal clutch
wear this is the only adjustment needed. Do not attempt to
change any other component. See the Maintenance
Manual for details.
Clutch Adjustment — Normal Wear
Clutch pedal free travel is usually 1 3/4 in. to 2 in. (34 to 51
mm). This should be your guide for determining whether
your truck needs clutch adjustment. Also, if it becomes
increasingly difficult to shift into gears, or the truck creeps
with the clutch pedal depressed, your clutch needs adjust-
ment. See the Maintenance Manual for the proper
adjustment procedures.
Some vehicles have automatic clutch adjustment. If yours
doesn't have this feature, adjustment will have to be done
by a trained certified mechanic. Have the adjustment
done before clutch pedal free travel is reduced to the min-
imum allowable 1/2 in. (13mm).
Clutch Linkage
The Regional Haul vehicle is equipped with a rod and
lever mechanical clutch linkage. Lubricate each pivot
point on the clutch linkage.
Automatic Transmissions
Service Intervals
Check daily with engine idling. See Table 1, “Recom-
mended Maintenance Intervals,” Page 150 for service
intervals.
