RIM A-TRACK 9W4343 - Caterpillar

General Information
The purpose of the off-highway truck actual gear indicator is to show the operator which transmission gear is actually engaged.The two main parts needed for this system to work are the actual gear indicator and the transmission control.
Actual Gear IndicatorThe transmission control tells the actual gear indicator which gear the transmission is in. The transmission control is located behind the operator seat on the 769, 773 and 777 trucks. The transmission control is located in the right side console on the 785 and 789 trucks.
Transmission Control 769, 773 And 777
Transmission Control 785 And 789Actual Gear Indicator
The actual gear indicator for off-highway trucks is a cab located box with a display window. The display should face the vehicle operator. Symbols show the operator when the vehicle is in REVERSE, NEUTRAL or in a Forward Gear.The left most symbol is the reverse symbol. The reverse symbol has a red light emitting diode (LED) behind it. The red light emitting diode will be ON and flashing when the vehicle is in REVERSE. The symbol looks like:
Reverse SymbolThe center symbol is a number symbol. The center symbol has a green LED light behind it. The green LED will be ON when the vehicle is in a FORWARD gear. This number changes and tells the operator which forward gear the transmission is in. For example, a "3" tells the operator that the transmission is in THIRD gear. The center symbol also provides system diagnostics at certain times.The right most symbol is the neutral symbol. It has an amber LED behind it that will be ON when the transmission is in NEUTRAL. The symbol looks like:
Neutral SymbolTransmission Control
The transmission control matches the transmission gear to the gear selected at the transmission shift lever. The transmission control gets information of the selected gear through the electrical system. The transmission control electrical system activates the hydraulic system (transmission and torque converter) through solenoids (up shift, down shift and lockup).The transmission control must get information from six sources: the shift lever switch, the transmission switch, the transmission speed sender, the bed raise switch, and the retarder brake switch or the secondary brake switch. Then the transmission control will send output to one of the three solenoids.The information the transmission control receives from the transmission switch is used and sent to the actual gear indicator.Normal Operation
Power-up Sequence
When the electrical system of the off-highway truck is activated, usually by movement of the key switch to the run or start positions, the actual gear indicator will power up. The following events should occur.1. The display will light up with all symbols showing for approximately one second. The center symbol will display a numeric digit which represents the type of transmission that the actual gear indicator "thinks" is on-board. The number displayed is dependent on the model of the truck as shown in the following chart. 2. After the one second test, the center digit will change to an "8" for approximately two seconds. This is done so that the