2.2.10. Removal, check and installation of the distributive mechanism
Removal of axes of yokes assembled
Before removal of axes assembled with yokes establish the clamps preventing loss of hydrojacks from yokes of valves.
Besides, when dismantling an axis of yokes spread out them according to number of the cylinder and inlet or final valves not to mix a detail at assembly.
Unscrew bolts of fastening of covers of bearings of camshafts. Remove covers of bearings, camshafts (shaft), pushers and jacks of gaps.
At camshaft extraction from a head of cylinders, be careful and attentive, preserving it against casual damages.
Bolts of fastening of covers of bearings turn on in stages in order to avoid camshaft deformation.
Check of an axial gap of a camshaft (shaft)
Establish camshafts or a shaft in a block head.
Displacing it in the axial direction, by the indicator measure an axial gap.
Nominal axial gap: 0,5–0,08 mm.
The most admissible axial gap: 0,20 mm.
If the axial gap exceeds the most admissible size, replace a head of the block of cylinders. If on basic necks of a camshaft there are damages, replace a camshaft (shaft). Clean channels of pass of oil in a head of cylinders.
Check diameter of basic necks of a camshaft. If the measured size does not correspond to standard value, check an oil gap between a neck and the camshaft bearing.
Standard value: 45,0 mm.
Measurement of an oil gap of necks of a camshaft
Clear covers of bearings and a neck of camshafts.
Establish camshafts in a head of the block of cylinders.
Put rumpled plastic calibres in the axial direction on all necks of camshafts.
Establish covers of bearings of camshafts.
Do not turn camshafts.
Again remove covers of bearings.
Measure rumpled plastic calibres in the widest place.
Nominal oil gap: 0,05–0,09 mm.
The most admissible oil gap: 0,12 mm.
After measurement completely remove the remains of the rumpled plastic calibre.
If the oil gap exceeds the most admissible size, replace a head of the block of cylinders or a camshaft.
Check of cams of a camshaft
Measure height of cams of a camshaft. If the measured size less maximum permissible value, replace a camshaft.
Height of cams (mm)
Height of cams (mm)
Camshaft check at the stand
Establish a camshaft on the stand and measure shaft palpation on an average neck. If palpation exceeds maximum permissible value, replace a camshaft.
Standard value: less than 0,02 mm.
Maximum permissible value: 0,10 mm.
Check of yokes and their axes
Check a surface of a press roller of a yoke of the valve and a yoke pusher, in the presence of wear or damages replace a yoke
Be convinced of smoothness of rotation of a press roller and replace a valve yoke in the presence of jamming or raised люфта.
Measure internal diameter of the plug of a yoke of the valve (under an axis). Replace a yoke if the increased wear of the plug takes place.
Examine an external part of a surface (on a circle) axes of yokes on which the yoke if on it it is noticed non-uniform or raised wear is established, replace an axis of yokes.
Examine and очичтите oil openings in an axis of yokes.
Check a gap between the plug and an axis of yokes. If the gap exceeds standard value, replace yokes and an axis of yokes.
Standard gap: 0,02–0,05 mm.
Installation of an epiploon of a camshaft
Put on a working edge of an epiploon on all its circle a thin layer of engine oil.
By means of a special opravka press an epiploon on a shaft.