We remove and install the crankshaft during engine overhaul.
Removing the crankshaft
Remove the main bearing caps.
a) Check for timing marks on the main bearing caps and cylinder block.
Cover numbers start at the front of the engine.
b) Remove the main bearing cap bolts, but do not remove them.
c) Using the 2 bolts as a lever, swing the main bearing cap and remove it.
Do not damage the threads of the bolts.
We apply marks on the removed parts in accordance with their location
Remove the crankshaft
Remove the upper main bearing shells.
Apply a relative position mark to the removed liner
Checking the crankshaft
Measure the diameter of the crankshaft connecting rod and main journals.
Connecting rod journal diameter:
- nominal 68.962 - 69.013 mm;
- rem. (0.25 mm) 68.712 - 68.763 mm;
- rem. (0.50 mm) 68.462 - 68.513 mm.
Main journal diameter:
- nominal 82.962 - 83.013 mm;
- rem. (0.25 mm) 82.712 - 82.763 mm;
- rem. (0.50 mm) 82.462 - 82.513 mm.
Maximum ovality 0.050 mm
Maximum taper 0.013 mm
If the dimensions of one neck differ from the nominal size, bore all the necks to the nearest repair size.
Determine the main bearing clearance with a plastic gauge.
a) Place the crankshaft in the cylinder block.
b) Place a plastic gauge across each root journal.
c) Install the main bearing caps.
d) Tighten the main bearing cap bolts.
Note: do not turn the crankshaft.
e) Remove the crankshaft main bearing caps.
f) Measure the maximum width of the flattened gauge by determining the value of the radial clearance.
Main bearing clearance 0.04 - 0.12 mm
Check the length of the main bearing cap bolt rod length.
Maximum length 120 mm
Check the thickness of the main bearing shells.
- nominal 2.456 - 2.464 mm;
- rem. (0.25mm) 2.706-2.714mm;
- rem. (0.50 mm) 2.956-2.964 mm.
If necessary, select a new bearing using the number stamped on the back of the old liner.
Installing the crankshaft
Install the main bearing shells by aligning the shell projections with the grooves in the main bearing seats.
Install the crankshaft thrust bearing shell on the # 4 main bearing.
Apply assembly grease (# З163О87) to the running surfaces of the main bearings and the crankshaft end thrust bearing.
Make sure the guide bushings are in the main bearing caps.
Install the crankshaft.
Install the main bearing shells aligning the tabs of the shells with the grooves of the main bearing caps
Apply assembly grease (# 3163087) to the running surfaces of the main bearings and the crankshaft end thrust bearing. Do not apply grease to the back of the liner!
Make sure there is no dirt or debris on the surfaces of the main bearing caps between the cap and the cylinder block.
Install the main bearing caps according to the numbers on the removal.
Align the guide bushings on the main bearing cap with the corresponding holes in the cylinder block.
Note: Make sure the covers are properly installed where they were removed from, numbered towards the engine oil cooler.
Numbering starts at the front of the engine.
Lubricate the threads and under the bolt heads with engine oil.
Install the main bearing cap by tapping it gently with a plastic hammer.
After reinstalling the cover, tighten the bolts.
Tightening torque 50 Nm
Tighten the bolts evenly in the sequence shown in figure 20. Perform each step on all bolts before moving on to the next step.
- first stage 60 Nm;
- second stage 80 Nm;
- turn the third stage 90 °.
- the first stage 120 Nm;
- the second stage completely loosen the bolts;
- third stage 60 Nm;
- fourth stage 85 Nm;
- turn the fifth stage by 120 °.
Make sure the crankshaft turns freely.
Using a dial gauge, check the axial movement of the crankshaft.
Axial travel 0.11 - 0.39 mm
If the axial clearance is greater than the maximum value, replace the thrust bearing of the main bearing, which is installed in the area of the main journal 4.
There are repair sizes of thrust bushings 0.25 mm and 0.50 mm.