What issue might cause a crawler dozer with an electronically controlled hydrostatic steering system to pivot left only when moving forward or reverse?

The issue that would cause a crawler dozer with an electronically controlled hydrostatic steering system to pivot left only when moving forward or reverse is likely related to a poor wiring connection at the pump for the left track. In a hydrostatic steering system, electronic signals control hydraulic flow to the tracks, allowing the dozer to maneuver. If there is a poor connection in the wiring, it could lead to insufficient hydraulic pressure being delivered to the left track when the dozer is in motion. This would result in the dozer being able to pivot to the left, as one track would have less power, thus making the vehicle turn in that direction more easily.

In this scenario, other potential issues, such as faulty hydraulic fluid, incorrect track tension, or worn-out steering components, while they could affect the overall performance of the dozer, would likely not specifically limit left pivoting motion under both forward and reverse conditions. Each of these factors would generally contribute to a different set of handling issues, making the wiring and corresponding hydraulic signals the most likely cause of the described behavior.