Utility Vehicle with Automatic Shift Control

A utility vehicle comprising:

• a. a chassis;
• b. left and right laterally spaced driven ground supports that support the chassis on the ground;
• c. an engine that is supported on the chassis;
• d. a hydraulic system that is supported on the chassis and that includes
• i. a tandem drive pump including first and second pumps, each being powered by the engine and having an output that can be varied by adjusting a setting of an associated swash plate,
• ii. first and second hydraulic drive motors, each of which is coupled to one of the pumps and to a respective one of the grounds supports, and each of the drive motors being operable in a low speed range and a high speed range, and
• iii. a drive control valve assembly that is actuatable to switch each of the drive motors between the low speed range and the high speed range thereof;
• e. a drive control system including
• i. an electronic controller that is electronically coupled to the swash plates and to the drive control valve assembly;
• ii. first and second manually actuated drive command devices, each of which is electronically coupled to the electronic controller and is operable to generate a drive command signal, a magnitude of which is dependent upon a degree of actuation of the drive command device;
• and
• iii. a drive control system that is coupled to the electronic controller and to the drive control valve assembly, wherein the electronic controller is configured to cause actuation of the drive control valve assembly to control each of the drive motors to automatically shift from the first speed range to the second range only if an average output speed of the rive motors exceeds a designated speed threshold.