PLATE A 4Z8643 - Caterpillar

Torque Converter Lockup Control
Illustration 1 g03622276
Torque Converter Lockup Control Switch - Move the switch to the upper position to enable the torque converter lockup clutch. Move the switch to the lower position to disable the torque converter lockup clutch. Note: Disable the torque converter lockup clutch when traveling downhill. With the torque converter lockup disabled, the transmission will be in torque converter drive mode. Shifting to a lower gear will minimize the need to use the service brake to slow the machine, and will result in lower axle oil temperature and extend service brake life.Only disable the torque converter lockup clutch when the operating conditions require the machine to stay in torque converter drive. Disabling the torque converter lockup will improve machine response when operating in short load, haul, and dump cycles.The lockup clutch feature allows the machine to maintain efficient speeds while transporting material. The torque converter lockup clutch operates in all transmission speeds except first speed forward. The lockup clutch will engage when the transmission output speed reaches the required value. The lockup clutch will disengage when the transmission output speed falls below a predetermined level and during gear shifts.