Inspection (Disassembly And Assembly): Commutator

Support the armature with a pair of V block and turn it to measure the runout of the surface not rubbed by the brushes using a dial gauge.
Standard value: 0.05 mm or less

Limit: 0.1 mm

Fig 1: Measuring Commutator Runout
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Measure the diameter of the commutator.
Standard value: 29.4 mm

Limit: 28.8 mm

Fig 2: Measuring Diameter Of Commutator
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
Measure the depth of the undercut between segments.
Standard value: 0.5 mm

Limit: 0.2 mm

Fig 3: Measuring Depth Of Undercut Between Segments
Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.