Remove the valve covers

Turn out the spark plugs

We set the piston of the first cylinder to the top dead center, for this we close the hole for the candle of the first cylinder with a finger and turn the crankshaft of the engine with the starting handle until the air begins to escape from under the finger. This will happen at the beginning of the compression stroke in the first cylinder.

Adjusting the thermal clearances of the engine valves of the GAZ-66 car

After making sure that the compression has begun, carefully turn the crankshaft of the engine with the starting handle until the pointer on the clutch housing coincides with the ball hammered into the flywheel (Figure 1), and for the GAZ-53 car, until the marks on the crankshaft pulley coincide with the central mark of the pointer in. m, t. (Fig. 2).

Adjusting the thermal clearances of the valves of the engine of the GAZ-66 and GAZ-53 car

When the piston of the first cylinder is at TDC on the compression stroke, the intake and exhaust valves must be completely closed.

Adjusting the thermal clearances of the engine valves of the GAZ-66 and GAZ-53

In this position, we set or check the gap between the rocker arm and the valve stem, which should be 0.25 - 030 mm on a cold (15 - 20 ˚ C) engine.

Adjusting the thermal clearances of the engine valves of the GAZ-66 and GAZ-53

It is allowed to reduce the gap to 0.15-0.20 mm for valves located along the edges of the heads: the first and eighth inlet, fourth and fifth outlet (Fig. 3).

If the gap does not match: - loosen the locknut of the adjusting bolt and, turning the adjusting bolt, set the required gap on the feeler gauge.

Tighten the locknut, keeping the bolt from turning, and check the clearance again.

The clearances for the remaining cylinders are adjusted in the order of operation of the cylinders 1-5-4-2-6-3-7-8 by turning the crankshaft ¼ turn when moving from cylinder to cylinder.

Adjusting the thermal clearances of the engine valves of the GAZ-66 and GAZ-53

To better navigate and speed up the process with quick-drying paint, we mark the drive pulley into four parts (Figure 6).