Removal
Remove the crankshaft.
Mark the corresponding connecting rods and bearing shells
Loosen the connecting rod nuts and remove the connecting rod caps, connecting rod rods and bearing shells. Mark the bearing shells. It is recommended to stack all removed parts in the order of installation.
Examination
Inspect the connecting rods for external damage.
The connecting rod cap fastening bolts must not be broken or crushed. If the bolts are damaged, replace the entire connecting rod.
The connecting rods must be replaced as a set.
When replacing connecting rods, their weight must be checked, since the difference in weight of individual connecting rods must not exceed? g. Weigh the connecting rods without bearing shells.
If necessary, modify the connecting rods in the places indicated in the figure. This can reduce the weight by 8 g.
Check the connecting rod head bushing. With a new bushing, the unheated piston rod should enter with light finger pressure.
If necessary, balance the connecting rods (work at a service station).
Installation
Wash all parts in gasoline and lubricate with engine oil.
Depending on the design, if necessary, replace 6 connecting rod caps. 2 types of bolts are installed:
1 - rigid bolt, length of threaded part a - about 13 mm, does not change.
2 — Expanding bolt, threaded length b = about 30 mm, must be replaced, as the expanding bolt is released with each tightening. Observe different tightening methods.
To remove the connecting rod cap bolts, it is advisable to clamp the cap in a vice, as shown in the figure. Use a suitable press to press new bolts into the connecting rod caps.
Insert bearing shells and connecting rods in accordance with the markings made. The parts must be installed in their original places.
When installing, the mark on the connecting rod should be located above the "arrow".
Unscrew the new nuts. First remove the protective grease from the nuts and lubricate them with engine oil.
Tighten the nuts on the three rigid connecting rod cap bolts to a tightening torque of 45 Nm.
For stretch bolts (see "2" in Figure 13-792), the nuts are tightened in 2 passes. This requires a torque wrench.
1st pass: tighten the nuts with a torque wrench to 30 Nm.
2nd pass: tighten the nuts with a hard wrench by 180° (1/2 turn). For better reading of the angle of rotation, first apply marks on the engine with chalk. There are also special protractors for turning fasteners at certain angles, for example, from Hazet.
After assembly, the connecting rods should tip downwards under their own weight.
Minor distortions that occur when tightening the bolts between the bearing halves can be eliminated by lightly striking both sides of the connecting rod with a hammer.
Check the connecting rod axial clearance with a feeler gauge. The wear limit is max. 0.7 mm.
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