BMW 3 series E30

Since 1983-1994 of release

Repair and car operation

14.17. A gear belt for a mechanism drive timing

THE GENERAL DATA

Today gear belts have found "the second breath". Almost all motor-car manufacturers equip the cars with an elastic drive. German designers have gone further away. They widely apply a double gear belt (Duplex) as reliable connection of a cam-shaft with krivoshipno-shatunnym the mechanism.

The gear belt has a number of advantages before a chain. It obviously is more expensive. To make a belt is much easier, than a chain. By and large, it is the closed tape from маслобензостойкой the rubbers, reinforced by a kapron cord with пирвулканизированными to it teeths. If to compare it to a chain comparison will appear not in favour of last. The belt is much easier than a chain that, naturally, should affect weight of the engine. Besides, the engine equipped with a belt, is much more silent than the colleague equipped with a chain. Also "elastic band" out of an engine casing that affects time of its installation or replacement is mounted. For example, at the author of these lines on replacement of belt ГРМ with its subsequent installation on labels 25–30 minutes leave. With a chain such focus will not pass.

At correct service and the control the gear belt goes long. Home producers, we will remind, give a guarantee on run in 60 thousand in km, foreign – and that it is more. Rover has managed to remove term of replacement of a belt to 160 thousand.

In what the correct control and service of this simple adaptation consists? Not less often, than km everyone 15-30 thousand correctness of position and a belt tension should be checked. However it does not mean that it is necessary to remove only a casing and to check up, whether on a place a belt. Is better to examine it, having removed from the engine. At times it is difficult to notice that one of teeths has overstrained. If it has already occurred, be assured that he will not stretch. Therefore, having removed a belt, make on it a mark a chalk, and further a tooth behind a tooth "banish" it. After installation also it is necessary to check position directing and натяжителя. All these elements should be on one axial, otherwise the belt will work with a warp that will not go to it on advantage.

The important factor for belt work – absence on its surface of oil. Whatever there was маслобензостойкая a rubber from which the belt is executed, nevertheless it not that case when "porridge oil you will not spoil". Here oil just to the detriment. Therefore it is periodically necessary to pay attention to a condition of epiploons. And if you have noticed an oil leak, try to eliminate it somewhat quicker. As practice shows, stay of a belt in the oil environment cuts its resource by half, and even three times.

If this control to ignore, consequences will not keep itself waiting long. Through 40-50 thousand in km for the account вытягивания a belt the necessary tension weakens also it starts to whip. As a result of it the heavy cam-shaft rotates not synchronously, and with backlog. This асинхрония motor works leads still большему to belt easing. As a result there are excessive loadings on teeths.

Breakage of several teeths can lead to that once the cam-shaft remains motionless while the knee will rotate successively. During such moments open valves meet pistons. Result – a regional ohm or a valve bend, its broken plugs, the broken off cam-shaft. Is, the truth, and exceptions when breakage passes almost without serious consequences. However such it is possible only on those cars in which specially on this case are available проточки in pistons. Our VAZs, namely cars, for example, concern them with engines VAZ-2105, 1300 cubic sm, and VAZ-2108, 1500 cubic see

If the car is not equipped by such engine, belt breakage manages to the owner in a round sum connected with capital repairs of the engine. Cost, for example, a belt on BMW reaches $40. Engine repair on the same Saab will manage in $5000. For вазовской the belt can be bought "nine" for $25. And here cursor repair will pull on $400.