- This type is a compromise between the full floating type and the semi floating type.
- In three-quarter floating rear axle, bearings are on the axle casing and hub.
- In this case, major part of vehicle weight is taken by axle casing and not by axle. This is the main advantage of three-quarter floating type over half floating type.
- The axle shafts do not have to withstand any shearing or bending; it has to take only the end loads and driving torque
- Thus, axle breakdown is less in this case compared to the Semi floating.
- Even though it is better than the semi floating type, it is not as robust as the full floating type.
Three quarter floating are is a compromise between the more bust full floating type & the simplest semi floating type (fig:15.1). In this bearing is located between the axle casing & the hub instead of between the axle casing & the. shaft as in case of semi-floating axle. As is clear from the figure, the axle shafts do not have to withstand any shearing or bending action due to the weight of the vehicle, which are taken up by the axle easing through the hub & the bearings provided the bearing lies in the plane of the road wheel. However, it has to take the end loads & the driving torque.
At one time, this type of axle was popular for cars & light commercial vehicles. However, with improvements in design, materials & fabrication techniques, the cheaper & simple semi-floating axles are again being preferred these days over the three-quarter floating type.