Diesel Data: Automotive Repair

Initial Inspection and Diagnostic Overview

CHECKING THE COMMUTATOR




1. Place the armature on a pair of V-blocks, and check the run - out by using a dial gauge.

Standard value
Armature run - out : 0.05 mm (0.002 in.)

Limit
Armature run - out: 0.1 mm (0.0039 in.)




2. Check the outer diameter of the commutator.

Standard value
Outer diameter of the commutator: 29.4 mm (1.157 in.)

Limit
Outer diameter of the commutator: 28.4 mm (1.118 in.)




3. Check the depth of the undercut between segments.

Standard value
Depth of the undercut between segments: 0.5 mm (0.020 in.)

Limit
Depth of the undercut between segments: 0.2 mm (0.079 in.)

OVERRUNNING CLUTCH
1. While holding the clutch housing, rotate the pinion. The drive pinion should rotate smoothly in one direction, but should not rotate in the opposite direction. If the clutch does not function properly, replace the overrun clutch assembly.




2. Inspect the pinion for wear or burrs. If the pinion is worn or burred, replace the overrun clutch assembly. If the pinion is damaged, also inspect the ring gear for wear or burrs.

FRONT AND REAR BRACKET BUSHING
Inspect the bushing for wear or burrs. If the bushing is worn or burred, replace the front bracket assembly or the rear bracket assembly.