Engine Mechanical: For J20 Engine 1D-123
Crankshaft thrust play
Measure this play with crankshaft set in cylinder block in
the normal manner, that is, with thrust bearing and lower
crankcase installed. Tighten crankcase bolts referring to
“Main Bearings, Crankshaft and Cylinder Block Removal
and Installation: For J20 Engine”.
Use a dial gauge to read displacement in axial (thrust)
direction of crankshaft.
If its limit is exceeded, replace thrust bearing with new
standard one or oversize one to obtain standard thrust
play.
Crankshaft Thrust Play
Standard: 0.10 – 0.35 mm (0.0039 – 0.0137 in.)
Limit: 0.42 mm (0.0149 in.)
Thickness of crankshaft thrust bearing
Out-of-round and taper (uneven wear) of journals
An unevenly worn crankshaft journal shows up as a
difference in diameter at a cross section or along its
length (or both). This difference, if any, is determined by
taking micrometer readings. If any one of journals is
badly damaged or if amount of uneven wear in the sense
exceeds its limit, regrind or replace crankshaft.
Limit on out-of-round and taper
0.01 mm (0.0004 in.)
Out-of-round
“A” – “B”
Taper
“a” – “b”
Main Bearings
Main bearings general information
• Service main bearings are available in standard size
and 0.25 mm (0.0098 in.) undersize, and standard
size has 5 kinds of bearings differing in tolerance.
• Upper half of bearing (1) has oil groove (2) as shown
in figure.
Install this half with oil groove to cylinder block.
• Lower half of bearing does not have oil groove.
Main bearings inspection
Check bearings for pitting, scratches, wear or damage.
If any malcondition is found, replace both upper and
lower halves. Never replace either half without replacing
the other half.
Standard
2.500 mm (0.0984 in.)
Oversize: 0.125 mm
(0.0049 in.)
2.563 mm (0.1009 in.)
1. Thrust bearing
2. Oil groove
I2RH01140183-01
I2RH01140184-01
I2RH01140185-01
I2RH01140186-01
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