Abstract: This disclosure relates to the design of pile cap assemblies configured to rotatably couple the torque tube of a photovoltaic solar tracker to multiple support piles that elevate the torque tube above the ground. The pile cap assemblies define low friction bearings that allow the torque tube to rotate smoothly within the low friction bearings. The pile cap assemblies also include numerous mounting hole configurations that allow for adjustment of a position of the pile cap assemblies with respect to the support piles. This allows for any small variation in positioning of the support piles to be accommodated.