Ford Sierra

3.2.1.8. Check of backlashes of a cranked shaft and rods

THE GENERAL DATA

Loose leaves of the first radical bearing (from outside a system drive timing) have больший the size, than loose leaves of other bearings, and both have an oil flute. In other bearings loose leaves from outside the block of cylinders have an oil flute, and from outside covers have a smooth surface.

Check of radial backlashes

The radial backlash in radical and шатунных bearings of a cranked shaft is measured by means of special measuring cores Plastigage from an artificial material. The measuring core laid along a neck (radical or шатунной) and clamped in the bearing is exposed to flattening. The radial backlash in the bearing can be defined (on the basis of a corresponding scale on packing of measuring cores) depending on width of the deformed core.

Conditions of measurement by means of measuring cores Plastigage:

  – Necks and loose leaves should be dry and are carefully degreased;
  – The cranked shaft should not change the position in process of installation and extraction of measuring cores;
  – The measuring core should be laid in half of loose leaf, on большем distance from an oil aperture in the loose leaf or a shaft neck;
  – Covers of bearings should be established manually, and their bolts should be tightened by the corresponding moment; it is impossible to strike blows to covers;
  – It is necessary to tighten only a bearing cover in which the radial backlash is measured; it is impossible to measure backlashes in all radical bearings simultaneously.

PERFORMANCE ORDER

1. To establish loose leaves on radical bearings in the block of cylinders of the engine and to establish in them a cranked shaft. 2. To lay on the first radical neck measuring core Plastigage. 3. To establish a cover of the radical bearing together with the loose leaf and to tighten fastening bolts the corresponding moment. 4. Cautiously to uncover the bearing and to measure by means of a scale delivered together with measuring cores, width of the deformed measuring core and on the basis of the table or the schedule to define a radial backlash in the bearing. 5. To compare the measured value to necessary size of a backlash (subsection 3.2.1.2.4 see). If the measured backlash exceeds admissible value it is necessary to use repair loose leaves. 6. In the similar way to measure a backlash in other radical and шатунных bearings.

Проврка an axial backlash

PERFORMANCE ORDER

1. After installation of a cranked shaft in the block of cylinders it is necessary to establish persistent half rings of a cranked shaft (oil flutes should be directed outside of the radical bearing), covers of bearings and to tighten their fastening by the corresponding moment. 2. To rest a measuring tip of the indicator of hour type against an end face of a cranked shaft and to measure its axial backlash. 3. To compare the measured values to necessary sizes (subsection 3.2.1.2.4 see).Если a backlash exceeds admissible value it is necessary to use repair persistent half rings accordingly большей thickness.

Check of piston rings and piston backlash in the cylinder

PERFORMANCE ORDER

1. After removal of rings from pistons it is necessary to measure their backlash in piston flutes, and after installation in cylinders in which they stood earlier, to measure width of the lock (backlash) between their ends (subsection 3.2.1.2.4 see). 2. To measure diameters of cylinders and diameters of pistons (in a directing part, below an aperture of a piston finger) at right angle to an axis of a piston finger. The piston backlash is equal in the cylinder to a difference of these two measurements. 3. By means of the special adaptation to establish rings on pistons so that inscriptions (or designations) have been directed towards a piston bottom. Cuts of rings to arrange at an angle nearby 120 °.