Renault Megane, Scenic

Since 1996 of release

Repair and car operation

Survey of radical bearings

Typical damages of loose leaves

And — Are scratched by alien particles - the particles which have plunged into a working layer of the loose leaf are visible In — an oil Lack - the top layer is erased With — Loose leaves are incorrectly located at installation - there are brilliant (polished) sites	D — the Neck is shown on a cone - the top layer is removed from all surface Е — Deterioration of edge of the loose leaf F — Malfunction of "weariness" - craters or pockets were formed

SURVEY

1. In spite of the fact that radical and шатунных bearings during an engine partition it is necessary to replace loose leaves, keep old loose leaves for detailed survey as they can give the valuable information concerning an engine condition. The size of loose leaves is printed on an underside and it is necessary to give this information to the supplier of new loose leaves. 2. Damage of loose leaves can be caused a greasing lack, hit on them of alien particles, an overload of the engine or corrosion (address to an illustration above). Irrespective of the reason before to collect the engine, it is necessary for eliminating. 3. For survey of loose leaves of bearings, remove them from the block of cylinders/covers/rods. Spread out from on a pure working surface in the same order as they stand in the engine. It will allow to find out, in which bearing the problem is localised. 4. The dirt and alien particles get to the engine various ways. They can be left in the engine after a partition or pass through filters or ventilation system картера. The grains of metal remained after a repoint or formed at usual deterioration of the engine often come across. The alien particles which have got to bearings actively вкрапляются in a soft working layer of loose leaves, where from easy to find out. The big particles do not plunge into a loose leaf material, and scratch the loose leaf and a neck. The best prevention of malfunction of the bearing for this reason - careful clearing of all components and maintenance during assemblage of the engine of faultless cleanliness. Besides, it is recommended to change impellent oil and the filter often and regularly. 5. The greasing lack has set of the interconnected reasons. Them can be: an overheat (does oil by less viscous because of what утоньшается its layer on loose leaves), an overload (wrings out oil from a bearing surface) or leaks (backlashes of bearings the oil pump is excessive, worn out or it is high engine turns). Blocking of lubricant channels which usually grows out несовмещения of lubricant apertures of loose leaves, also leads to a lack of greasing and puts the bearing out of action. When a bearing cause of defect - the greasing lack, a working layer of the loose leaf is erased or exfoliated from its steel basis. The temperature can increase to such values when the basis steel becomes blue from an overheat. 6. The driving manner also influences bearing service life. Full gas and long work on slow turns (an engine overload) give very high loading on bearings that leads to a pushing off from loose leaves of an oil film. As a result loose leaves bend and on them the network of small cracks (malfunction of "weariness") is formed. Finally, the working layer of the loose leaf of the bearing will break up to pieces and comes off a steel basis. Trips on short distance lead to corrosion of loose leaves, since the engine heats up insufficiently to push away compressed water steams and коррозийные gases. Steams are adsorbed by impellent oil, forming acid and a sediment. When such oil will get to engine bearings, the working layer of loose leaves of bearings is oxidised. 7. Wrong selection of the loose leaf also will lead to malfunction of the bearing. Too big loose leaves which are densely sitting down in the bearing, leave an insufficient working backlash that leads to a greasing lack. 8. If it is necessary to establish new loose leaves before to collect the engine it is required to measure working backlashes to be convinced of correctness of a choice of loose leaves (address to Section Survey коленвала). If there are any doubts concerning what loose leaves should be used, consult on representative Renault.