- Off-Highway Truck:
- 793B (S/N: 1HL1-UP)
Use Special Instruction, REHS0130, "Procedure to Retrofit 3516B Engine In 793B Off-Highway Trucks Equipped With Vital Information Management System (VIMS)" with the following publications:
- Special Instruction, REHS0715, "Removal and Installation of the Engine and Torque Converter for the 784B, 784C, 785, 785B, 785C, 789, 789B, 789C, 793, 793B and 793C Off-Highway Trucks/Tractors"
- System Operation, SENR6059, "Vital Information Management System"
- Service Magazine, SEPD0341, 20 January 1997, "New Ether Starting Aid Groups Include Flexible Hose Assembles Instead of Tube Assemblies"
- Testing And Adjusting, SENR1450, "793C and 793C XQ Off-Highway Truck Power Train"
In some cases, the VIMS configuration software must be upgraded. The VIMS source software may need to be updated also. Before you start the procedure, review the latest Service Magazine, "Updated VIMS 9.62 Class of Onbaord Software" article and download the appropriate files from the Caterpillar Service Information System.
Additional Parts
Additional parts are required in order to complete the upgrade. These parts update the 793B Off-Highway Trucks with the following performance features:
- 3516B Standard Stroke Engine
- 9U-9822 Transmission Ar
- 199-9847 Power Train Electronic Control Module or 178-5174 Power Train Electronic Control Module
3516B Standard Stroke Engine
| Altitude | Elevation | Part Number | Description |
|---|---|---|---|
| Low | less than 2750 m (9000 ft) |
156-6230 | Engine Arrangement |
| High | greater than 2450 m (8000 ft) |
187-4593 | Engine Arrangement |
Note: Modifications to the water lines may be necessary in order to mate with the existing radiator assembly.
The 3516B Standard Stroke Engine offers the following features:
- Gross power increased from 1600 kW (2160 hp) to 1700 kW (2300 hp) with the installation of 9U-9822 Transmission Ar .
- Sump capacity increased allowing up to 500 service hours between oil changes.
- Acceleration improved by approximately 30 percent.
- Emission of nitrous oxide is reduced by 20 percent.
- Future compatibility with the oil renewal system is provided.
9U-9822 Transmission Ar (S/N: 4GX)
9U-9822 Transmission Ar offers the following enhancements:
- Higher speeds in sixth gear
- Larger clutch discs and additional clutch discs are required for the increased horsepower.
- Increased size of the piston which increases the service life of the discs and of the seals
- Additional planet gears which increase the service life of the gears and of the bearing
EPTC II Control
To take advantage of the latest improvements, update the transmission to EPTC II control. Reference the following publications:
- Service Magazine, SEPD0221, 29 August 1994, "Description and Usage of the Electron Programmable Transmission Control (EPTC II)"
- Service Magazine, SEPD0387, 20 October 1997, "New Off-Highway Truck Electronic Group (EPTC II) Used"
- Service Magazine, SEPD0427, 27 July 1998, "Improved Transmission (EPTC II) Control Speed Sensor Used on Certain Off-Highway Trucks"
- Service Magazine, SEPD0559, 22 January 2001, "The 144-0178 Speed Sensor (Transmission) Must be Used on Off-Highway Trucks"
Note: The harness code within EPTC II must be changed after 9U-9822 Transmission Ar is installed. EPTC II will then allow the ECM to select the higher horsepower.
Modes of Operation
The two operating modes are "Dual Horsepower" and "Multi-torque". These operating modes were created in order to allow the installation of 3516B Standard Stroke Engines in 793B Off-Highway Trucks. The engine software uses the transmission to determine the operating mode.
Dual Horsepower Mode
Dual Horsepower uses only one of the following horsepower ratings:
- The horsepower is 1610 kW (2160 hp) if the machine is not equipped with 9U-9822 Transmission Ar .
- The horsepower is 1715 kW (2300 hp) if the machine is equipped with 9U-9822 Transmission Ar .
Dual Horsepower mode is chosen when any of the following conditions exist:
- The engine control module (ECM) is unable to establish Caterpillar data link communication with the transmission electronic control module.
- The engine control module (ECM) establishes Caterpillar data link communication with the transmission electronic control module, but the ECM does not receive the proper response for the transmission serial number.
"Multi-torque" Mode
"Multi-torque" uses multiple torques which are determined by the transmission gear. In order to enter the "Multi-torque" mode, the engine control module (ECM) must receive a transmission serial number that begins with S/N:4GX
.
Manually set the Operating Mode
To override the operating mode that was selected by the engine, use the Electronic Technician (ET). Be aware of the following statements when you manually set the operating mode:
- Use Testing And Adjusting, SENR1450, "793C and 793C XQ Off-Highway Truck Power Train".
- The Engine Control Module can only be overridden to "Multi-torque" if a 4GX transmission is present on the CDL.
- The Engine Control Module can be overridden to "Dual Horsepower" under all conditions.
- The override remains until the ECM powers up.
Note: When the Electronic Technician (ET) starts the configuration screen, an available option is "Rating Selection". This option allows the user to select "Dual Horsepower" or "Multi-torque". Be aware that this parameter does NOT display the current status of this feature. "Multi-torque" is displayed when the screen is opened regardless of the actual operating mode. There is no feedback that would indicate that the operating mode was changed. The display shows the selected operating mode. This issue will be addressed in a later version.