Note. Standard values for all checks are given in the section «Service data and specification» at the end of the chapter.
Camshaft runout
1. Put the prisms on the marking plate and lay the shaft on the prisms with necks No. 2 and 5.
Attention. Do not lay neck No. 1 on the prism (closest to the shaft sprocket), because it has a different diameter from the others.
2. Install the stem of the dial gauge vertically on neck #3.
3. Rotating the shaft with your hands in one direction, determine the beating of the camshaft (arrow oscillation amplitude).
4. If the measured value is out of specification, replace the camshaft with a new one.
Camshaft lobe height
1. Measure the height of the camshaft cam with a micrometer.
2. If the measured value is out of specification, replace the camshaft with a new one.
Oil clearance on the camshaft journal
Camshaft journal diameter
Measure the outer diameter of the camshaft journal with a micrometer (A).
Camshaft bed diameter
Tighten the camshaft bracket bolts to the specified torque.
With the help of a caliper (A) measure diameter (IN) camshaft bed.
Oil gap on the camshaft journal
(Oil clearance) = (Bed diameter) - (Neck diameter)
If the calculated value exceeds the specifications, replace the camshaft or cylinder head, or both.
Note. The camshaft bracket is not replaced separately, as they are bored together with the cylinder head. Replace the cylinder head assembly.
Checking the axial clearance of the camshaft
Install the dial indicator leg on the front end of the camshaft parallel to its axis. Moving the shaft back and forth, measure the axial clearance:
Check if the following dimensions are within tolerance:
Size «A» groove bed No. 1 of the cylinder head. Standard value: 4.000-4.030 mm.
Size «B» camshaft flange. Standard value: 3.877-3.925 mm.
Taking into account the given technical conditions, a decision is made to replace the camshaft and / or cylinder head.
Camshaft sprocket runout
1. Put the prisms on the marking plate and lay the shaft on the prisms with the necks No. 2 and 5.
Attention. Do not lay neck No. 1 on the prism (relay closest to sprocket), because it has a different diameter from the others.
2. With a dial indicator (A) measure sprocket runout (arrow amplitude).
If the measured value is out of specification, replace the sprocket.
Valve tappet
Check tappet surfaces for cracks and wear.
In the presence of such defects, replace the pusher.
The gap between the pusher and the walls of the socket
Outer diameter of pusher
Measure with a micrometer (A) outside diameter of the valve lifters.
Pusher seat diameter
With the help of a caliper (A) measure the diameter of the pusher seat.
Gap between pusher and socket wall
(Gap) = (Socket diameter) - (Outer diameter of pusher)
If the calculated clearance is out of specification, based on the measured tappet and seat diameters, replace the tappet and/or cylinder head.