To provide flexible connection between two rigid shaft at some angle with each other constantly varying universal joints are used.
In other way we can say that for connecting two shafts inclined with on another at some angle as well as for transmitting rotary motion from engine to road wheel universal joints are used. Transmission of power under this variable condition is impossible without using universal joints. universal joint consists of two yokes. A central piece join the two yokes
Different types of joint are used in motor vehicles:
1) Flexible coupling joints
2) Hooks or ring type of universal joints
3) Multi coupling U joints
4) Yoke type U Joints
Servicing of Universal Joint
1. The Universal joint should be lubricated after specified interval of time recommended by manufacturer with proper grade of grease.
2. For greasing, grease nipples are provided at the cross of universal joint.
3. While greasing ensured that the old grease is completely replaced by new grease.
4. If any noise comes from the universal joint dismantle the joint, remove the needle roller bearings (four numbers) from the yokes of the universal joint.
5. After cleaning inspect all the needles, if require replace needles and reassemble and check for serviceability.
