Grand Cherokee 4WD L6-242 4.0L VIN S MFI (1993)
Starter Motor: Description and Operation
Bosch Starter Motors
Fig. 1 Bosch Starter Motor
Bosch starters are either direct drive or gear reduction type starters. Bosch direct drive starters incorporate an overrunning clutch type starter drive. A
solenoid switch is mounted on the starter motor.
Bosch gear reduction starters use six permanent magnets in place of conventional, wound field magnets, to save weight, eliminate field winding to
case shorts, and improve cold start performance. The gear reduction system uses a planetary gear train to transmit armature rotation to the pinion shaft. A
solenoid switch is mounted on the starter motor drive end shield.
