DETROIT DIESEL 53
Starting Motor 7.3
The starting motor bearings (bushings) are lubricated by oil saturated wicks which project through each bronze bushing
(one at each end and one at the center) and contact the armature shaft. Oil can be added to each wick by removing a
pipe plug which is accessible on the outside of the motor (refer to Section 15.1).
The starting motor drive pinion and the engine flywheel ring gear must be matched to provide positive engagement and
to avoid clashing of the gear teeth. Flywheel ring gear teeth have either no chamfer or a Bendix chamfer. The Sprag
clutch cannot be used with a ring gear with a Dyer chamfer.
Remove Starting Motor
Failure of the starting motor to crank the engine at normal cranking speed may be due to a defective battery, worn
battery cables, poor connections in the cranking circuit, defective engine starting switch, low temperature, condition of
the engine or a defective starting motor.
If the engine, battery and cranking circuit are in good condition, remove the starting motor as follows:
1. Remove the ground strap or cable from the battery or the cable from the starting motor solenoid. Tape the end of the
cable to prevent discharging the battery from a direct short.
2. Disconnect the starting motor cables and solenoid wiring.
NOTE: Tag each lead to ensure correct connections when the starting motor is reinstalled.
3. Support the motor and remove the three bolts and lock washers which secure it to the flywheel housing. Then pull the
motor forward to remove it from the flywheel housing.
Check the starting motor, if required, in accordance with the Delco-Remy "Cranking Circuit" maintenance handbook.
Install Starting Motor
To install the starting motor, reverse the procedure outlined for removal. Tighten the 5/8"-11 starter attaching bolts to
Keep all of the electrical connections clean and tight. When installing wiring terminal leads to the starting motor and the
solenoid switch, tighten the No. 10-32 connections to 16-30 lb-in torque and the 1/2"x 13 connections to 20-25 lb-ft
November, 1973 SEC. 7.3 Page 3