TM-9-2320-273-34

TRUCK TRACTOR, LINE HAUL; LIGHT EQUIPMENT TRANSPORTER; TRUCK CHASSIS; MEDIUM EQUIPMENT TRANSPORTER

TECHNICAL MANUAL; DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE

DECEMBER 1980

TM-9-2320-273-34 - Page 166 of 801

TM9-2320-273-34

(2) Set up a dial indicator gage and measure the run-out of the commutator. The total run-out

must not exceed 0.003 inch.

(3) Check the armature for grounds with a 115-volt ac test light by touching one probe to a

commutator bar riser and the other to the armature core (fig. 5-50). Test all commutator bars in this man-

ner. If the test light glows, the armature is grounded and must be replaced.

TA 002232

Figure 5-50. Testing Armature for Grounds.

(4) Check the armature for short circuits by turning the armature slowly in a growler while

holding a thin steel strip (such as a hacksaw blade) about 1/32-1/16-in. away from the armature core

(fig. 551). A short circuit will pull the steel strip against the armature core and cause the strip to vibrate.

Replace the armature if a short circuit is found.

5-38