Crankshaft End Play Measurement; Crankshaft Main Bearings - Jeep 1979 CJ-5 Technical & Service Manual

1B-28 ENGINES
(2) Use Piloted Driver J-21872-3 to press pin com-
pletely out of piston. Note position of pin through gauge
window of remover support.
Pin lispntlii
(1) Inspect pin and pin bore for nicks and burrs
Remove as necessary.
NOTE: Never reuse piston pin after it has been in-
stalled in and removed from a connecting rod.
(2) With pin removed from piston, clean and dry
piston pin bore and replacement piston pin.
(3) Position piston so that pin bore is in vertical
position. Insert pin in bore. At room temperature, the
replacement pin should slide completely through pin
bore without pushing.
(4) Replace piston if pin jams in pin bore.
listiSiiflii
(1) Insert Pin Pilot J-21872-2 through piston and
connecting rod pin bores (fig. 1B-50).
(2) Position pin pilot, piston and connecting rod on
Support J-21872-1.
(3) Insert piston pin through upper piston pin bore
and into connecting rod pin bore.
(4) Position Piloted Driver J-21872-3 inside piston
pin.
(5) Use arbor press to press piston pin through con-
necting rod and piston until pin pilot indexes with mark
on support.
NOTE: The piston pin requires a 2,000 pound (907.2 kg)
press-fit. If little effort is required to install piston pin
in connecting rod, or if rod moves along pin, replace
connecting rod.
(6) Remove piston and connecting rod assembly
from press. Pin should be centered in rod, ±0.0312 inch
(0.792 mm).
CRANKSHAFT
The nodular iron crankshaft is counterweighted and
balanced. The crankshaft has twelve counterweights.
Both have seven main bearing journals and six con-
necting rod journals. End thrust is controlled by the No.
3 main bearing.
An oil slinger is provided at the rear main journal,
inboard of the rear oil seal. The component parts and
crankshaft are individually balanced. Then the complete
assembly is balanced as a unit.
Service replacement dampers, crankshafts, flywheels,
torque converters and clutch components are balanced
individually and may be replaced as required without
balancing the complete assembly.
Removal or Replacement
If the crankshaft is damaged to the extent that re-
conditioning is not feasible, it must be replaced. Re-
moval and installation procedures are outlined under
Cylinder Block.
Crankshaft End Pliy I i i s i r i n i t
The crankshaft end play is controlled at the No. 3
main bearing insert which is flanged for this purpose.
(1) Attach dial indicator to cylinder block adjacent
to No. 3 main bearing (fig. 1B-50).
(2) Pry shaft forward with flat-bladed screwdriver,
set dial indicator, push rod on face of crankshaft
counterweight and set to zero.
(3) Pry shaft fore and aft. Read dial indicator. The
end play is the difference between the high and low
readings. The correct crankshaft end play is 0.0015 to
0.0065 inch (0.002 to 0.0025 desired) [0.038 to 0.165 mm
(0.051 to 0.064 mm desired)].
Fig. 1B-50 Measuring Crankshaft End Play
(4) If end play is out of specifications, inspect
crankshaft thrust faces for wear. If no wear is apparent,
replace thrust bearing and check end play. If end play is
still out of specifications, replace crankshaft.
NOTE: When replacing the thrust bearings, pry the
crankshaft fore and aft to align the faces of the thrust
bearings before final torque tightening.
Crankshaft Main Bearings
. v;.
' The main bearings are steel-backed, micro-babbitt,
precision type. The main bearing caps are numbered
(front to rear) from 1 through 7, and an arrow indicates