LEEVENSPARK

Front Wheel Drive In front wheel drive both the engine and transmission system are assembled in one unit, which is mounted at the front of the vehicle. This arrangement provides the following ad­vantages. (i) Compact construction is obtained. (ii) Flat floor of passenger compartment is possible in absence of propeller shaft tunnel or gearbox bulge. (iii) Good traction is provided as majority of weight is taken by the driving wheels.  (iv) Engine can be mounted transversely so that either bonnet length is reduced or the size of the passenger compartment is increased. (v) Good steering stability is exhibited as driving thrust of the wheels is aimed in the direction that the vehicle is intended to follow. Also the layout rarely suffers from the oversteer characteristics. The front wheel drive vehicles require more complicated drive shafts, but in view of the many advantages the layout is very suitable for small cars. In the typical front wheel drive layout shown in Fig. 26.59, the transv

Front Wheels Alignment 27.2.1. Need for Front Wheel Alignment For free movement of the road-wheels with the least of effort, opposite wheels must be approximately parallel to each other when the vehicle is in motion along a straight path (Fig. 27.8). Each wheel has a tendency to negotiate a path perpendicular to its own axis of rotation. Therefore, if the front wheels are aligned for converging towards the front, then during movement in the forward direction both wheels try to roll close together. On the other hand, if the wheels are aligned for diverging towards the front, the wheels try to roll farther apart. Therefore due to free rolling tendency the average path followed by both wheels have a continuous tendency to either push together or pull apart. Consequently, while rolling forward, each wheel simultaneously tends to slip laterally, so a continuous cross tread scrub action is established, resulting in excessive tread wear, heavy steering and probably leading to poor fuel consum