3-1. ENGINE MAINTENANCE (CONT)
d. Cylinder Block (Cont).
Tachometer Drive (Cont).
AND INSPECTION (SHEET 2 OF 2)
Compressed air used for cleaning purposes will not exceed 30 psi. Use
only with effective chip guarding and personal protective equipment
(goggles/shield, gloves, etc). Failure to do so could cause serious
injury to eyes and possible blindness. If you hurt your eyes or if a
foreign object is blown into your eyes, seek medical attention
(a) Immerse tachometer drive in cleaning
solvent P-D-680 and slowly move up
and down to thoroughly clean inte-
rior. Dry using compressed air.
After drying, immerse tachometer
drive in clean engine oil and rotate
gear with fingers to lubricate
(b) Inspect tachometer drive for cracked
body, chipped or broken drive gear
teeth, excessively worn drive shaft
or bushings, blocked oil hole, or
thread damage. Rotate drive gear
with fingers and check that it turns
smoothly. Measure drive gear clear-
ance using thickness gage. Replace
tachometer drive as an assembly if
clearance is not 0.01 to 0.02 inch
or if any of the above conditions
(a) Lower tachometer drive into cylinder block bore. Mesh tachometer drive
and engine gears, and rotate tachometer drive body until oil hole faces
away from engine.
(b) Using soft hammer, carefully tap tachometer drive into bore until flush
with cylinder block.
(c) Connect tachometer drive cable end to tachometer drive. Tighten cable
nut using pliers.
(d) Install engine left front side panel (refer to TM 5-3805-262-20).