The main dimensions of the crankshaft are given in Figure 1.

The crankshaft is cast, cast iron, five-bearing.

It is possible to regrind the crankshaft journals during repairs with a diameter reduction of 0.25; 0.5; 0.75; and 1 mm.

The axial movement of the crankshaft is limited by two persistent half rings.

They are inserted into the sockets of the cylinder block on both sides of the middle main bearing, with a sintered metal half-ring (yellow) on the rear side, and a steel-aluminum one on the front side.

Half rings are made in two sizes - normal and increased in thickness by 0.127 mm.

Осмотр и ремонт коленчатого вала двигателя ВАЗ-2123

Crankshaft bearing shells are thin-walled, steel-aluminum.

Upper crankshaft bearings 1, 2, 4 and 5 with a groove on the inner surface, and the lower bearings without a groove.

Liners of the 3rd support (upper and lower) without a groove.

The connecting rod bearings (upper and lower) also have no groove.

Repair liners are made of increased thickness for the crankshaft journals, reduced by 0.25; 0.5; 0.75 and 1 mm.

The flywheel is cast iron, cast, with a pressed-on steel toothed rim for starting the engine with a starter.

The flywheel is centered by the front bearing of the gearbox drive shaft, pressed into the crankshaft.

On the rear plane of the flywheel, near the toothed rim, there is an alignment mark in the form of a tapered dimple.

It should be against the crank pin of the fourth cylinder.

Technical condition check and repair

Crankshaft

Inspect the crankshaft. Cracks anywhere on the crankshaft are not allowed.

On the surfaces mating with the working edges of the oil seals, scratches, nicks and risks are not allowed.

Осмотр и ремонт коленчатого вала двигателя ВАЗ-2123

Install the crankshaft with the outer main journals on two prisms (Figure 2) and check the runout with the indicator:

- root necks (no more than 0.03 mm);

- seating surfaces for the sprocket and the bearing of the transmission drive shaft (no more than 0.04 mm);

- surface mating with the oil seal (no more than 0.05 mm).

Measure the diameters of the main and connecting rod journals. The necks should be sanded if their wear is more than 0.03 mm or the ovality of the necks is more than 0.03 mm, as well as if there are seizures and risks on the necks.

Grind the necks with a reduction in diameter to the nearest repair size (see Figure 1).

When grinding, observe the dimensions of the fillets of the journals, similar to those shown in figure 1 for the normal dimensions of the crankshaft.

The ovality and taper of the main and connecting rod journals after grinding should be no more than 0.005 mm.

The displacement of the connecting rod journals from the plane passing through the connecting rod and main journals axes after grinding should be within 0.35 mm (see Figure 2).

To check, install the shaft with the extreme main journals on the prisms and align the shaft so that the axis of the connecting rod journal of the first cylinder is in a horizontal plane passing through the axes of the main journals.

Then use the indicator to check the vertical displacement of the connecting rod journals of 2, 3 and 4 cylinders relative to the connecting rod journal of the 1st cylinder.

After grinding the necks, polish them with diamond paste or GOI paste.

After grinding and subsequent finishing of the necks, remove the plugs of the oil channels, and then process the plugs' seats with the А.94016 / 10 cutter, put on the А.94016 spindle.

Thoroughly rinse the crankshaft and its channels to remove abrasive residues and blow with compressed air.

Press in new plugs with the A.86010 mandrel and mark each at three points with a center punch.

On the first cheek of the crankshaft, mark the amount of reduction of the main and connecting rod journals (for example, K 0.25; W 0.50).

Earbuds

No adjustments must be made on the liners. Replace the liners with new ones if they are scored, scratched, or peeled off.

Осмотр и ремонт коленчатого вала двигателя ВАЗ-2123

The gap between the liners and the crankshaft journals is checked by calculation (by measuring the parts).

It is convenient to use a calibrated plastic wire to check the gap. In this case, the verification method is as follows:

- Thoroughly clean the working surfaces of the liners and the corresponding neck and place a piece of plastic wire on its surface;

- install a connecting rod with a cap or a main bearing cap on the journal (depending on the type of journal being tested) and tighten the nuts or bolts.

Tighten the connecting rod bolt nuts to 51 Nm (5.2 kgcm), and the main bearing cap bolts to 80.4 Nm (8.2 kgcm);

- remove the cover and use the scale on the package to determine the size of the gap by flattening the wire (Fig. 3).

The nominal design clearance is 0.02-0.07 mm for connecting rod and 0.026-0.073 mm for main journals.

If the clearance is less than the limit (0.1 mm for the connecting rod and 0.15 mm for the main journals), then these bushings can be used again.

If the gap is greater than the limit, replace the liners on these journals with new ones.

If the crankshaft journals are worn out and are ground to a repair size, then replace the liners with repair ones (increased thickness).

Persistent half rings

As well as on the inserts, no adjusting operations can be performed on the half rings. Replace half rings with new ones if they are scuffed, scratched or peeled off.

The half rings are also replaced if the axial clearance of the crankshaft exceeds the maximum permissible - 0.35 mm.

Select new half rings with a nominal thickness or increased by 0.127 mm in order to obtain an axial clearance in the range of 0.06-0.26 mm.

The axial clearance of the crankshaft is checked with an indicator as described in the article "Repair of the VAZ-2123 engine".

The axial clearance of the crankshaft can also be checked on the engine installed on the vehicle.

In this case, the axial movement of the crankshaft is created by pressing and releasing the clutch pedal, and the size of the gap is determined by the movement of the front end of the crankshaft.

Flywheel

Check the condition of the toothed rim and replace the flywheel if the teeth are damaged.

If the flywheel is discolored on surface 3 (Fig. 3), check the rim tightness on the flywheel.

The rim must not turn when the torque is 590 Nm (60 kgfm).

Осмотр и ремонт коленчатого вала двигателя ВАЗ-2123

On surface 1 of the flywheel, adjacent to the crankshaft flange, and on surface 3 under the clutch disc, scratches and scoring are not allowed.

Remove scratches and scratches on surface 3 with a groove, removing a metal layer no more than 1 mm thick. In this case, grind surface 2 as well, keeping the dimension (0.5 ± 0.1) mm.

When grooving, it is necessary to ensure the parallelism of surfaces 2 and 3 relative to surface 1. The non-parallelism tolerance is 0.1 mm.

1. Place the handwheel on a mandrel, centering it on the bore with an emphasis on surface 1, and check the runout of planes 2 and 3.

At the extreme points, the indicator should not show beats exceeding 0.1 mm.