TM-9-2320-272-23-1

TRUCK, 5-TON, 6X6, M939, M939A1, AND M939A2 SERIES TRUCKS (DIESEL)

TECHNICAL MANUAL; FIELD MAINTENANCE MANUAL; VOLUME 1 OF 5

SEPTEMBER 2012

TM-9-2320-272-23-1 - Page 380 of 1313

FIELD MAINTENANCE

EXCESSIVE VIBRATION OR CLUNKING

INITIAL SETUP:

Tools and Special Tools

Tool Kit, General Mechanic's: Automotive

(Volume 5, WP

0826, Table 1, Item 56)

Personnel Required

(2)

References

Point to Point Schematics

References (cont.)

Volume 2, WP

0216

Volume 2, WP

0218

Volume 2, WP

0219

Equipment Condition

Vehicle parked and engine shut down.

(TM

9-2320-272-10)

TROUBLESHOOTING PROCEDURE

EXCESSIVE VIBRATION OR CLUNKING

NOTE

Conduct this malfunction test if engine excessive vibration or clunking. This procedure will

check for loose or damaged motor mounts and loose vibration damper.

STEP

1.

ARE ENGINE MOUNTING BRACKETS AND PADS LOOSE OR DAMAGED?

Check engine mounting brackets and pads for looseness or damage.

CONDITION/INDICATION

ARE ENGINE MOUNTING BRACKETS AND PADS LOOSE OR DAMAGED?

DECISION

YES - Replace or tighten loose or damaged mounting brackets and pads (Volume 2, WP

0216). Go to Step (3)

to verify problem is solved.

NO - Go to Step (2).

TM 9-2320-272-23-1

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