Main bearing clearance check
1. Remove the main bearing cap and lower bearing.
2. Clean the bearing and crankshaft main journal.
3. Place a piece of plastic gauge on each crankshaft main journal.
4. Install the bearing caps and tighten the mounting screws. Tightening torque: 54-59 Nm.
Note: Do not turn the crankshaft.
5. Remove the cover and lower bearing shell.
6. Using the control scale, measure the width of the flattened section of the gauge at its widest point. Nominal clearance: 0.022-0.040 mm.
7. If the clearance exceeds the maximum allowable value, replace the main bearing shell with a new one with the same marking and repeat the check.
Attention: Machining of inserts or cover is not allowed.
8. If the clearance in the new bearings still does not correspond to the required value, select a larger or smaller insert (in accordance with the marking) and recheck.
Note: if the required clearance is not achieved by selecting bearings, replace the crankshaft.
Crankshaft bearing marking
Note: Letter markings for all five crankshaft bearings are stamped on the bottom of the cylinder block.
Label | Inner diameter, mm |
A | 54,000-54,006 |
b | 54,006-54,012 |
With | 54,012-54,018 |
Crankshaft journal marking
Label | Neck diameter, mm |
A | 49,962-49,968 |
b | 49,956-49,962 |
With | 49,950-49,956 |
Note: All five crankshaft journals are marked on the front crankshaft counterweight.
5. Letter marking of the size group of the main journals
Main bearing marking
Class | Color coding | Liner thickness, mm | |
№1,2,4,5 | №3 | ||
AA | Blue | 2,014-2,017 | 2,011-2,014 |
A | Black | 2,011-2,014 | 2,008-2,011 |
IN | - | 2,008-2,011 | 2,005-2,008 |
WITH | Green | 2,005-2,008 | 2,002-2,005 |
D | Yellow | 2,002-2,005 | 1,999-2,002 |
6. Letter marking of the insert
7. Color mark
Selection table for main bearing shells
Checking the axial run of the crankshaft
9. Use an indicator to measure the axial run-up of the crankshaft by moving it back and forth with a screwdriver. Nominal value: 0.05-0.175 mm. Limit value: 0.2 mm.
10. If the measured value is greater than the limit, replace the thrust bearing.
Checking geometric parameters
11. Measure the diameter of all main and connecting rod journals with a micrometer. Nominal value: 49.950-49.968 mm (root neck); 44.954-44.972 mm (crankpin).