Subaru Legacy/Outback

1999-2003 of release

Repair and operation of the car

The repair procedures which are not connected with extraction of the engine from the car - four-cylinder engines

Reduction of the piston of the first cylinder in situation VMT

General information

The highest point of a piston stroke in the cylinder is called as the Top Dead Point (TDP). Strictly speaking, in 4-stroke engines in the course of rotation of a cranked shaft this situation is reached by each of pistons twice: once at the end of a step of compression and the second - at the end of a final step. During the performing of settings of phases of gas distribution and installation of a corner of an advancing of ignition the provision VMT of the end of a step of compression of the piston is in most cases used (usually the first cylinder).

Need for reduction of the piston(s) in situation VMT arises when carrying out many procedures, in particular such as removal/installation of camshafts and components of the GRM drive.

Some engines are designed in such a way that at a provorachivaniye of cranked or distributive shaft at the taken-off gas-distributing belt / chain there can be an input of valves in contact with the bottoms of pistons that is fraught with risk of damage of the corresponding internal components, up to destruction of molding of a head of cylinders.

Do not allow change of provision of shaft after removal of a belt!

Procedure performance order

Reduction of any of pistons in situation VMT is made by a provorachivaniye of a cranked shaft of the engine. If to take a detached view of the engine of the GRM drive, the direction clockwise will be the normal direction of rotation of a cranked shaft. Remember that attempt of a provorachivaniye of a shaft counterclockwise can lead to violation of adjustments of phases of gas distribution. Cylinders are numbered from No. 1 on No. 4 from the right board of the car to left and in front back. The first is the right forward cylinder; the second - left forward, etc.

Disconnect a negative wire from the battery. For the purpose of simplification of a provorachivaniye of the engine turn out all spark plugs.

For the purpose of ensuring access to VMT tag on a camshaft cogwheel, uncover the GRM drive (see the Section Removal and installation of forward covers of the GRM drive).

By means of the key (ST 49977300 – engines of 2.0 l or ST 49977100 - engines of 2.5 l) which is put on a bolt of fastening of a pulley of a cranked shaft turn the last in the direction of normal rotation until the adjusting tag in the form of an arrow (And) on a cogwheel of a camshaft of the left is not developed vertically up.

When performing of the condition stipulated in the previous paragraph the engine will be given to provision VMT of the end of a step of compression of the piston of the first cylinder.