Universal joint consists of spider(cross) and 4 grease-filled roller bearings. It can transmit large torque at low friction. Spider with journal pegs and bearing cases as outer ring were hot forged or cold formed and machined. They are later carburized in furnace so that increased ruggedness and wear resisitance are obtained. Parts are finally ground to designed size under severe tolerance. Oil seal as well as dust cover are also in use to protect internal journal area from intrusion of foreign material. Variety of grades and materials are selected to repond to extreme conditions such as very hot / very cold temperatures.
