SHAFT 6K2034 - Caterpillar

Introduction
For Specifications with illustrations, make reference to Specifications For 3406 Spark Ignited Engine Attachments, Form No. SENR3868. If the Specifications in Form SENR3868 are not the same as in the Systems Operation and Testing And Adjusting, look at the printing date on the back cover of each book. Use the Specifications given in the book with the latest date.Electrical System
Two electrical systems are available to provide engine protection. In each case, engine shutoff is achieved by grounding the magneto. Each system is also capable of activating the gas shutoff valve if provided.1. For the self-powered protection system, oil pressure (OP) and water temperature (WT) protection are provided. When combined with a mechanical overspeed contactor switch (MOS) [(provided standard on engine)], full protection is obtained. An energized-to-shutoff (ETS) gas shutoff valve (GSOV) is available which is activated by magneto voltage.2. An energized-to-run (ETR) non-auto-start-stop protection system provides OP, WT and OS (overspeed) protection. An electronic speed switch (ESS) is used for the OS protection. This system is fully independent and requires an external 24 volt power source and an energized-to-run (ETR) gas shut-off valve.Electrical Schematics And Wiring Diagrams
Electrical schematic foldouts are provided in this section with the text for each protection system. Use the electrical schematics to follow the circuit operations of the protection systems.Point-to-point wiring diagrams for the protection systems, junction boxes, and starting, charging, and tachometer circuits are located in the Wiring Diagrams Section of this module. Use the diagrams for component position layout.Components
The components that follow may be used on one or more of the two protection systems available on the 3406 spark ignited engine.Electric Service Meter
The electric service meter group is self-powered. A magnetic pickup mounted on the flywheel housing provides voltage (starting at 200 engine rpm) to power the electric service meter which records clock hours with quartz accuracy. A separate magnetic pickup must be used for each service meter; it cannot be shared with the digital tachometer, electronic speed switch, or electronic governor magnetic pickup.Water Temperature Contactor Switch (WTS)
A water temperature contactor switch is located in the cooling system. The unit is nonadjustable. Thermal expansion of the element operates a micro-switch that signals the shutoff solenoid which causes engine shutdown. The water temperature element must be in contact with the coolant. If overheating occurs due to low coolant level or no coolant, the sending unit will not function.The water temperature sending unit can also be wired into an alarm system or light to signal high water temperature. After an overheated engine is allowed to cool, the contactor automatically resets itself.
Contactor Switch (Water Temperature)Magnetic Pickup (MPU)
Magnetic Pickup
(1) Clearance dimension. (2) Magnetic pickup. (3) Wires. (4) Locknut. (5) Gear tooth. (6) Housing.The magnetic pickup is a single pole, permanent magnet generator made of wire coils around a permanent magnet pole piece. As the teeth of the flywheel ring gear go through the magnetic lines of force around the pickup, an AC voltage is made. A positive voltage is made when each tooth goes by the