BEARING 3G8115 - Caterpillar

Refer to SENR6498 Schematic foldout and SENR6597 Electronic Troubleshooting for additional information when performing the following procedures.Vehicle Battery Circuit Requirements
Grounding
Improper grounding will cause uncontrolled and unreliable circuit paths. Stray electrical currents can result in damage to the engine's crankshaft main bearings, crankshaft journal surfaces or other engine components, especially aluminum components. They can cause electrical noise that may degrade the performance of the vehicle's electronic control system, electrical communication equipment, and radio.
Proper grounding for vehicular and engine electrical systems is necessary for proper performance and reliability. The problems stated above are often difficult to diagnose and repair.Starting Motor and Alternator
All ground paths must be capable of carrying any conceivable fault currents. An AWG #4 (or larger) cable is recommended between the engine ground stud and the vehicle frame (or starting motor negative post).The wire size from a ground must be of adequate size to handle full alternator charging current. An AWG #4 (or larger) cable is recommended to handle alternator currents. For engines which have the alternator grounded to an engine component, the component MUST be electrically isolated from the engine and a ground strap must connect that component to the battery negative post.A maximum of three (ring) terminals are to be connected to the engine ground stud to ensure ground connection integrity. More than three terminals can cause the stud to easily loosen. The ECM is capable of operating with a 12V or 24V battery system. CMS and EMS modules have a power supply range of 18 to 24 volts. Two required terminals are determined by Caterpillar. 1) engine ground stud to vehicle (-)Battery connection and ...2) engine ground stud to ECM (-)Battery connection.
The cab must not be grounded to the engine ground stud because noise transients (affecting control system performance) can be introduced.
Caterpillar recommends splicing like wire sizes together as a method of reducing ring terminal congestion at the engine ground stud.
Engine ground stud to starting motor to (-)Battery connection.Electrical Power Supply Connections To ECM
Vehicle Battery Circuit Requirements and Considerations
* Grounding Proper grounding for vehicle and engine electrical systems is necessary for proper performance and reliability. Improper grounding results in unreliable electrical circuit paths. Stray electrical currents can damage main bearings, crankshaft journal surfaces and aluminum components. They can also cause electrical noise degrading the performance of the control system, vehicle systems, and radio. These problems are often very difficult to diagnose and repair.All ground paths must be capable of carrying any conceivable fault currents. An AWG #4 or larger cable is recommended between the engine ground stud and the frame or starting motor negative post. AWG #4 wire is recommended to handle alternator currents. A maximum of three ring terminals are to be connected to the engine ground stud to ensure ground connection integrity.
Ground Stud to Starting Motor to BatteryTwo of these ground stud connections have already been defined by Caterpillar; the stud to vehicle (-)Battery connection and the stud to ECM (-)Battery connection.More than three terminals can cause the stud to loosen too