Copyright Goodheart-Willcox Co., Inc. 817 Chapter 24 ∣ Track Steering Systems Common Track Steering System Designs The three most common steering systems equipped on tractors with twin tracks are the following: • Dual-path hydrostatic drive. • Steering clutch and brake. • Differential steer. Dual-Path Hydrostatic Drive Systems Hydrostatic-propelled track-type tractors are equipped with dual-path hydro- static transmissions. As mentioned in Chapter 13, Hydrostatic Drives, dual-path hydrostatic transmissions use two separate hydrostatic transmissions. One pump and one motor are responsible for driving the left track and one pump and one motor are responsible for driving the right track. See Figure 24-5. Most late-model hydrostatic-propelled track-type tractors use joystick con- trols, Figure 24-6. Dual-path transmissions provide forward and reverse propulsion as well as steering. When the left and right hydraulic motors are propelled in the same direction and at the same speed, the tractor moves either forward or in reverse. When the motors are propelled in the same direc- tion but at different speeds, the tractor performs a power turn. Dual-path hydrostatic transmissions are capable of counter rotating. The operator can perform a coun- ter rotation turn at variable speeds, ranging between a slow counter rotation to a fast counter rotation. Some machines, such as the power train in an older Case track loader that is described later in this chapter, are capable of counter rotating, but only at fixed speeds. Goodheart-Willcox Publisher Figure 24-4. The neutral steer method involves shifting one track into neutral and propelling the other track in either forward or reverse. Goodheart-Willcox Publisher Figure 24-5. Dual-path hydrostatic transmissions use a pump and motor to drive the left track and a separate pump and motor to drive the right track. Goodheart-Willcox Publisher Figure 24-6. This Caterpillar D5K dozer is propelled using the left-hand joystick. The tractor moves in the same direction as the operator directs the joystick: forward, reverse, left, or right. Neutral Steer to the Right Left track forward Right track shifted into neutral Engine Pumps Motor Motor Right- side HST Left- side HST Left Forward Reverse Right