Abstract: An adjusting tool for performing precision adjustment of rotary elements disposed in inaccessible areas including an elongated barrel. A driver is rotatably mounted on one end of the barrel and has a coupling configuration for mating with the rotary element to be adjusted. An elongated shaft is journalled within the barrel and a transmission connects the same to the driver. A knob is disposed at the opposite end of the barrel and is connected to the shaft to rotate the same. A scale is carried by the actuator for movement therewith and an index device is disposed in proximity to the scale and is mounted on the tool for movement relative to the scale. A brake is employed for selectively holding the index device against movement on the tool.