Fig. 180 Check the axial play of the connecting-rod
1. Dismantling and Inspection of the Connecting-rod and its Bearing
II. Assembly of the Connecting-rod and its Bearing
1. Check the axial clearance of the connecting-rod (Fig. 180)
2. Dismount the connecting-rod cap and check the oil film clearance(0.15
to 0.30mm).
Check the matching marks on the connecting-rod and the cap. Pay
attention to the installation marks during re-assembly.
Dismount the connecting-rod cap. Use a thicknes feeler gauge to measure
the oil film clearance at the widest point (Fig. 66):
Standard model: 0.020-0.051mm,
Model with expansion of 0.25: 0.019-0.065mm,
Max. oil film clearance is 0.08mm. In case of oil film clearance being
greater than the max. , replace the bearing. Polish or replace the crank-
shaft if necessary.
3. Remove the piston and the connecting-rod assembly
4. Dismount the connecting-rod from the piston (see Section II, Chapter II)
Section 2 Dismantling and Inspection of
the Connecting-rod and its Bearing
Fig. 181 Installation of the connecting-rod bearing
Fig. 182 Assembling of the piston and the connecting-rod
Front end mark
(Recess)
Front mark
(Bulging)
1. Assemble the piston and the connecting-rod (Fig. 182).
(1) Paste engine oil on the piston pin and piston pin hole.
(2) With the front end marks of the piston and the connecting-rod on the
same side, push in the piston pin with the thumb.
(3) Press the piston pin into the piston when freezing -40°C or heating
up connecting rod to 100°C with a special tool.
2. Install the upper bearing (Fig. 181)
(1) Select the bearing before installation.
(2) Align the bulging part of the bearing with the recess of the
connecting-rod or its cap, and mount the bearing into the connecting-
rod and its cap.
3. Install the piston and
connecting-rod assembly
(Fig. 183)
(1) Slip a short hose over
the connecting-rod bolt to
protect the crankshaft
from damage.
72
Summary of Contents for JL481Q
Page 1: ......
Page 9: ...5 Fig 3 Components Assembly Drawing of MR479Q MR479QA Engine ...
Page 10: ...6 Fig 4 MR479Q MR479QA Engine and Its Power System ...
Page 11: ...7 Fig 5 Assembly Drawing of Engine and Its Auxiliaries MR479Q MR479QA ...
Page 12: ...8 Fig 6 Electronic Control Fuel Injection System in Engine MR479Q MR479QA ...
Page 13: ...9 Fig 7 Front view of Engine JL481Q MR481QA ...
Page 14: ...10 Fig 8 Sectional elevation of Engine JL481Q MR481QA ...
Page 15: ...11 Fig 9 Electronic Control Fuel Injection System in Engine JL481Q MR481QA ...