marked on the piston top.
The connecting rod as used in production is
marked both on the rod dnd the cap on the
camshaft side. 1£the standard bearing does
not give the correct clearance on the crank-
shaft, .OOZ"undersize bearings are available.
The desired clearance on the connecting rod
bearing is .0015" to .OOZ". The spur on the
bearing insert which prevents it from turn-
ing in the rod is on oppos ite side s of the
crankshaft when the rod is correctly as-.
sembled. The oil spray hole in large end of
connecting rod should face the camshaft side.
Tighten the connecting rod capsc rews to
ZO to
l5 foot Ibs. torque. Do not file the
connecting rod, cap or insert to obtain bearing
fit.
The a
lWTIinurn piston-";;~d-N62-'jil7:i '~d;b~ve
is cam ground. When fitting ca'ffi ground
pistons use; a .OOZ" feeler strip I/Z" wide
between the cam or tight side of cylinder .~~ll •..
With feeler strip in place at tightesU)oint,:.:~ou· .
should be able to move the pi!iton~ya slight.
. . ,~ '. . '\ - '.. . .
push with thumb. If recommerid~<iClearance,
can not be obtained hone or 'rebore for next
larger size: piston. Minimu~' clea;ance_is ..
•001" to .OOZ" between. piston arid.cylinder.
wall. ' ..
The bearings are not provided with shims.
The rod or cap should never be filed to obtain
bearing adjustment.
T'he camp'r'es'sio'n 'rings ·6f'the tractor s are
tapered and have a small pit mark: on tht' top
side. The standard size service ring set will
.. consist,of·"'.chromium plated top compression
~'ring ttiat ~ij~;nl?t be tapered and tilt' spcond
.'~ompre·ssioh ·ring. which will be tapered. All
,'tapered rings will have a pit mark on the top
·"side. The. lower' compression ring will
Ill'
fitted with~n.exp;mder. The oil control ring
.will also be._supplied with an expander .
,."~_)3~-··~·::~ . .: .. :"-.:
,. '.Fit ~'~h ritlg' in the lower part of the cylinder
The pistons are serviced hi standard size block bor~<w~ere piston ring travel stops or
.0035", .OZO"and '.040" over!iiz~s ~o·pr'o,,:ide where the wear is the least. Try each ring in
pistons when reboring or honingls necessary.':':" the groove un·the piston in which it will
1.)('
The piston pin {S:fitted~ith~;W:~ light push installed to ,;Jttt surethat it is free ..
fit in the connecting rod and'~ ,'light push fit The lowest pb:rtion of the c ylinde
I' bore 1S
in the piston. They -should be replaced ,when chamfered 450 to permit installation of the
.0003" loose or wnennoisy •..
j;•.•...·-:~-:;f'ft:,.~-' '-'_·:·~,-:--rings·'without the need of a ring cr,rnpressor.
, '.,:<' '. Pistons and rods must be installed from the
The piston pin is supplied in' .003'~..,.nd ~00511", .bottom and on the side of the crankshaft
0:ver~izes for repairs. ~.l1e st~:rld.ar;d pin opposite the camshaft.
S1ze 1S .5435. The production cyhnder block .
is 'machined slightly tapered, being .0005" When fitting standard or oversize piston pins
smaller at the top than at the bottom. The, use a spiral fluted expanding reamer or a
bo)-e size is Z.377". The piston is fit.~itli-<'· hone. The bushing in the connecting rod is
ap:proximately .OOZ"clearance. The maxi--·.'·" very thin and great care must be exercised
mum allowable cylinder .wear is approxi- when reaming. A very light cut must be used
mately .010". at all times. Be sure the oil hole in the bush-
,-. ing is in line with the oil holp. in the top of
The production ring gap is f"om .007" to the connecting rod. Clean the oil hole dfter
.01Z".· The ring side clearance in the piston reaming. The' pin fits in the piston with a
ring groove is.0015" to .0035". Standard line to line fit and in the connecting rod with
rings may be used for service untilreboring a .0003" loose fit. A good method of petermin-
is necessary - then .0lO" or .040" oversizes ing the type of fit is to use a light push fit in.
are available and the engine should be re- the piston and a very light push fit in the
bored to these standard sizes. The piston connecting rod.
rings should be replaced if the side clearance
exceeds .0045" or the end clearance exceeds
.050"; The cylinder wall should be refinished
if the standard ring, when new, has .046" or
more'clearance. '. .
The connecting rod has removable bearing
inserts which should be replaced if the
clearance exceeds .004". The crankshaft
should be replaced
if out of round more than
.003". The side' play of the connecting rod is
from .006" to .010" and should be replaced if
it exceeds .014".
i
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