Removal, check and installation of a camshaft

Removing

Disassemble the engine (see above section "Engine disassembly and assembly").

Pull out the camshaft. Care must be taken when doing this, as the bearings usually stick to the shaft and may fall off and be damaged when the shaft is removed.

Remove and mark bearings.

Examination

Check the tight fit of the gear on the camshaft.

Check for wear on the cams and camshaft at the bearing locations (those. whether the running surfaces of the cams are worn and whether the surfaces of the protrusions are even).

Check the camshaft gear tooth profile for wear.

Check the gap between the teeth of the gears of the camshaft and crankshaft. It should be 0.00-0.05 mm. Can the clearance be adjusted? only by installing another camshaft.

The camshaft gear has the correct dimensions if, when it is carefully rotated in different directions, a barely perceptible play is felt during a change in the direction of rotation. The gap between the gear teeth is too small if the camshaft, when turned in the opposite direction, lifts the crankshaft out of the bearings.

With an excessively large gap, a camshaft with other dimensions can be installed. To identify gears of different sizes on the end sides of the camshaft gears facing the cams, a digital marking is embossed (For example, "-1,0", "+1", "+2" etc.). The number shows how many hundredths of a millimeter the radius of the pitch circle differs from the nominal size.

Attention! Don't confuse the number "0" labeled "ABOUT", which serves to install the gears of the gas distribution mechanism drive. For the crankshaft gears, there are no differences and, accordingly, designations.

Installation

Lightly file the edges of the bearing oil holes (if necessary). Install bearings (from flywheel side) so that the protrusions are located in the recesses of the housing. Bearing N3, as a centering, perceives radial loads and therefore has shoulders on both sides for the camshaft.

Lubricate the bearing journals and camshaft cams with engine oil. Install the shaft so that the gear tooth indicated by the mark "ABOUT", is located between the two teeth of the crankshaft gear, which are indicated by punched points.