YOKE 9V2399 - Caterpillar

General Information
Illustration 1 g00719183
Rest Position (1) Return Spring (2) Solenoid (3) Pull-In Winding (4) Start (S) Terminal (5) Hold-In Winding (6) Battery (Bat) Terminal (7) Key Start Switch (8) Solenoid Contacts (9) Motor (Mtr) Terminal (10) Shift Lever (11) Field Winding (12) Pinion Drive (13) Pinion (14) Armature (15) BatteryA DC series wound motor is used as the starting motor. The starting motor has field winding (11) and armature (14). The excitation and armature windings are connected in series. The pinion end of the armature shaft has splines for pinion drive (12) .The solenoid is an integral part of the starting motor. The solenoid pushes the pinion drive (12) with the pinion (13) forward through the shift lever (10) and the plunger. The end of the plunger is a spool which is connected to the shift lever. Return spring (1) helps return pinion drive (12) and shift lever (10) to the rest position after key start switch (7) is released and solenoid contacts (8) have been opened. A semi-solid link mechanism prevents welding of the solenoid contacts.The starting motor has a two-stage mechanical pinion drive (12) that protects armature (14) from an overspeed condition. The pinion drive also allows a smooth engagement of pinion (13) into the flywheel ring gear. The pinion drive is held on the splines of the armature shaft. The pinion drive is connected to the pinion (13) through the teeth of the integral overrunning clutch. Shift lever (10) moves the pinion drive (12) axially in the direction of the ring gear. 37-MT And 41-MT Operation
Illustration 2 g00719202
Partial Engagement (1) Return Spring (2) Solenoid (3) Pull-In Winding (4) Start (S) Terminal (5) Hold-In Winding (6) Battery (Bat) Terminal (7) Key Start Switch (8) Solenoid Contacts (9) Motor (Mtr) Terminal (10) Shift Lever (11) Field Winding (12) Pinion Drive (13) Pinion (14) Armature (15) BatteryWhen the key start switch (7) is closed, the following components are energized: start (S)terminal (4), pull-in winding (3) and hold-in winding (5). The solenoid plunger pulls the shift lever (10) against the force of the spring (1). The shift lever pushes the pinion drive (12) toward the engine flywheel. The armature (14) has not yet turned. The solenoid contacts (8) have not closed. This sends starting motor current to the excitation windings and the armature windings. If the pinion (13) can immediately engage the flywheel ring gear, the pinion moves forward. When the pinion reaches the end of the drive pinion shaft and the solenoid contacts (8) close. The starting motor is now in partial engagement.
Illustration 3 g00719206
Blocked Engagement (1) Return Spring (2) Solenoid (3) Pull-In Winding (4) Start (S) Terminal (5) Hold-In Winding (6) Battery (Bat) Terminal (7) Key Start Switch (8) Solenoid Contacts (9) Motor (Mtr) Terminal (10) Shift Lever (11) Field Winding (12) Pinion Drive (13) Pinion (14) Armature (15) BatteryIf a pinion tooth meets a ring gear tooth, the pinion cannot immediately mesh with the ring gear. The solenoid contacts (8) close as the meshing spring is compressed through the