TM 5-3820-233-35/2
cessive gear lash, scoring, pitting or bearing wear. A
b. Removal
rattling noise is an indication of excessive gear lash,
whereas a whining noise is a result of too little gear lash.
(2) Refer to the Operator's Manual and
The correct backlash for the gear train is 0.003 to 0.008
remove the muffler and air cleaner.
inch.
(3) Refer to the Operator's Manual and
d. Installation. Reverse the steps 1
through 7
remove the hoods, side panels, and tie rods.
under "Gear train removal".
(4) Remove the flywheel and flywheel
Note.
(5) Remove the blower drive gear (para .37).
Refer to figure 30-3 and install gears
in the gear train with the timing
(7) Remove the camshaft and balancer shaft
marks (O-O and R-R) as indicated.
53. Crankshaft and Main Bearings
c. Cleaning, Inspection, and Repair
a. General. The crankshaft assembly is located at
(1) Clean all parts with an approved cleaning
the bottom of the cylinder block, and is supported by
solvent and dry thoroughly.
five main bearings. The main bearings are of the
(2) Inspect idler gear for chipped teeth and
replaceable type and are used at each journal. A main
wear. Replace a defective gear.
bearing consists, of two shells. The upper shell is
(3) Inspect idler gear bearing for scoring,
located in crankcase main bearing support and the lower
pitting, wear, and overheating. Replace a defective
shell is seated in the main bearing cap.
bearing.
b. Removal
(4) Gear train noise usually indicates ex
(1) Drain the engine oil (Operator's Manual).
(3) Remove
Lie
air
cleaner
(Operator's Manual).
(4) Remove the hoods, side panels, and tie
rods (Operator's Manual).
(5) Drain the cooling system.
(7) Remove the flywheel and flywheel
(10) Remove the lubricating oil pump and
(11) Remove the pistons and connecting rods
(12) Remove the crankshaft pulley and front
crankshaft and main bearing.
c. Disassembly. Disassemble the crankshaft and
main bearings in the numerical sequence as illustrated
Figure 27-6. Checking flywheel housing
concentricity.
d. Cleaning, Inspection, and Repair
(1) Clean all parts with an approved clearing
solvent and dry thoroughly.
3-44