Allis-Chalmers Model G - Crankshaft Service; Crankshaft Removal and Assembly

CRANKSHAFT
. ,
PUlLEY
PULLING CRANKSHAFT GEAR
Removal
Remove the engine from the tractor. Re-
move the clutch and flywheel. Remove the
crankshaft fan pulley and the timing gea r
cover. The crankshaft pulley may be re-
moved by using two capscrews and the OTCpuller with a 1" x l-l/Z" spacer with a 600
center. Do not pry on die cast gear cover
or turn capscrews in against cover. ReInOve
the oil sump and the main bearing cap. Re-
move the connectinH rod bearing caps.
Check the crankshaft journals for wear,
scoring and out-of-round. The shaft should
be replaced if worn or out-of-round more
than .003". .OOZ"undersize bearing shells
are provided for service. The bearings do
not use shiIns, and if the shaft is worn under-
LOWER
.,: ;::1 ••
SEAL
INSERT
~-.) .'"..~
size the undersize bearings should be used
for service. Check the end of the crankshaft
at point contacted by oil seal and the crank-
shaft pulley at point contacted by oil seal. If
worn excessively at either place, they should
be replaced. The end clearance of the shaft
should be maintained within .003" to .007".
The clearance itmst be checked with all parts
in place including the crank jaw which is used
to retain the thrust washers in position. It
is best to check end clearance before dis-
assembly. It will not be necessary to dis-
mantle the engine to adjust end clearance
until such time as it is increased to .011".
However, if the engine is downfor any other
reason the end clearance should be adjusted
to the specified limit.
Assembly'
The main bearing inserts may be installed
without removing crankshaft if a small pin
is inserted in the crankshaft oil hole and the
upper shell rotated out of place. The main
bearing shell has an oil hole in the upper half
and is solid on the lower half. The spurs on
the shells to prevent turning in the block are
diametrically opposite. The main bearin~ oil
clearance should be from .0015"to .OOZ'and
should be adjusted if it reaches .004"or more.
Do not file main bearing caps or inserts.
Tighten the main bearing nuts to 70 to 80foot
pounds. Tighten pal nuts to 10foot lbs.
Both thrust washers should be placed on the
shaft with the bevel on the inside diameter
towards the first crank throw of the shaft.
The steel thrust plate goes against the bronze
thrust washer with the large surface towards
G - 18