Mitsubishi 4DQ3 Service Manual page 19

(S) Main bearings
Inspect each main bearing for evidence of wiping
or fatigue failure, for scratches by dirt particles
imbedded and for improper seating on the bore
(bearing cap). On the basis of findings, determine
whether the bearing should be replaced or not.
Check each main bearing to be used in engine
reassembly to see whether it will provide the speci­
fied radial clearance. This can be accomplished in
this manner.
Install the main bearings on the crankcase, less the
crankshaft, securing each bearing cap by tightening
its bolts to 8.5 kg-m (61.5 lb-ft) and read the
diameter in the two directions (A) (B), in indicated
below. Mike the journal and, from these readings,
compute the radial clearance.
Sp ec i fi ca t io ns
Item
Fit of main
bearings on
journals
Camshaft
(1) Check the camshaft end play as outlined for the
timing gears. Where the end play exceeds the
repair limit, replace the thrust plate with a new
one.
Specifications
Nominal
Item
value
5.0
Camshaft end
(0.197)
play
(2) Inspect the camshaft journals for abnormal wear
and damage; the camshaft must be replaced if an y
of its three journals is found in bad condition
beyond repair.
(3) Mike each cam of the camshaft to read D1 (cam
height) and Dz (diameter), and compute the
difference between D1 and 01 . If this difference
is less than the service limit, replace the camshaft.
U n it : m m (in .)
Repair
Standard
limit
0.03 -0.089 0.200
((0.0012 -0.00350) (0.00787)
Unit: mm (in.)
Standard
0.05 -0.112
(0.00197 -
(0.012)
0.00441)
Repair
limit
0. 3
Measuring main bearing ID
Positions for miking main bearing