CB9A-020 page 13
MAINTENANCE
c. Lift the crosshead assembly and connecting rod off the top of the crankcase.
NOTE: The connecting rod parts are not interchangeable and must be reassembled with the
same upper and lower halves. To avoid confusion, it is advisable to work on one connecting
rod at a time, or to mark the individual halves with corresponding numbers.
d. Remove the opposite connecting rod and crosshead assembly in the same manner as outlined in
step 8.
8. Rest the crosshead assembly on a bench. Carefully drive the wrist pin and wrist pin plugs out of the
crosshead and connecting rod using a suitable pin driver or an arbor press. Removal of the pin releases
the crosshead assembly from the connecting rod.
9. If necessary, the wrist pin bushings can be replaced after the crossheads are removed. Connecting Rods
with new brass bushings must be honed to the proper size after installation.
Inner Dimensions: 0.8753" to 0.8756" (22.233 mm to 22.240 mm).
10. To replace the crankshaft bearings, the crankcase must be disassembled, and the crankshaft removed.
Refer to "Bearing Replacement" for disassembly instructions.
COMPRESSOR ASSEMBLY
Compressor assembly is generally the opposite of compressor disassembly. Before reassembling, clean each
part thoroughly. Check all machined surfaces for burrs or roughness, and file lightly if necessary.
NOTE: If any of the O-rings or gaskets are removed or disturbed during service, it is recommended they be
replaced with new.
1. CRANKCASE ASSEMBLY
After replacing the crankshaft, bearing carrier, and bearing carrier assembly (see "Bearing Replacement"),
the connecting rod and crosshead can be installed.
a. Coat the wrist pin, the wrist pin bore in the crosshead assembly, and the bushing in the connecting rod
with grease, then attach the connecting rod to the crosshead assembly.
b. Start the wrist pin in the bore of the crosshead assembly and tap lightly until the pin begins to project
through to the inside of the crosshead assembly.
c. Slide the connecting rod up inside of the crosshead assembly and align the bushing with the wrist pin.
d. Lightly tap the wrist pin through the connecting rod until it is centered in the crosshead assembly.
NOTE: The wrist pin should be snug in the crosshead assembly. The connecting rod should rotate
freely on the wrist pin, but should not be loose.
e. Dip the wrist pin plugs in grease and press them in place.
f. Place the bearing halves into each half of the connecting rod, aligning the bearing tangs with the slots
in the connecting rod. Coat the bearing with grease.
g. Set the top of the connecting rod over the crankshaft journal. Replace the connecting rod cap,
remembering that the dots on the connecting rod and cap must be on the same side.
h. Start the nuts on the connecting rod bolts and torque per the Bolt Torque Table.
i. Follow this same procedure for the opposite connecting rod.
2. CROSSHEAD GUIDE
a. Place the crosshead guide gasket on top of the crankcase.
b. Lubricate the inside bore of the crosshead guide with light oil.
c. Set the crosshead guide over the piston rods and the crossheads, and slowly lower it against the
crankcase. Make certain that the crosshead assemblies are started straight in the bores of the
crosshead guide to prevent binding when lowering the crosshead guide into position.
d. Install the crosshead guide capscrews loosely.
3. Fill the crankcase with oil. See "Lubrication" for proper amount. Squirt oil into the crankshaft, roller
bearings, crankshaft journals, and crosshead assemblies so they will have lubrication at start up.
4. Attach the inspection plate and the inspection plate gasket to the crankcase.
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