Crankshaft oil seal: common defects and their signs

1. Deformation
   • Motor oil level lowers.
   • The engine loses power.
   • Stains of lubricant appear on the timing belt.
2. Mechanical damages
   • Motor oil consumption increases.
   • There are troubles in the clutch operation.
   • The timing belt wears out faster.
   • Oil level warning light is on.
   • The crankshaft pulley wears out faster.

How to replace a crankshaft oil seal?

Approximate lifetime limit of the crankshaft oil seal is 100 000 - 150 000 operational kilometers. The component can’t be repaired, that is why it is replaced if defects are found.

In order to install a new crankshaft seal you should visit a service station. This procedure is rather laborious and can have specific features for cars of certain models. Moreover, the action sequence depends on which oil seal is out of order - the rear or front. For example, to perform replacement of the front oil seal on the car it is often required to demount the radiator or a special plate which covers the crankshaft pulley. Sometimes in order to gain access to the component the engine needs to be lifted and the crankshaft pulley - removed.

The algorithm of rear oil seal replacement includes a more complex procedure. The gearbox and the clutch unit will have to be dismounted. During replacement it is very important to install a new component correctly. The inner side of the oil seal can get bent, resulting in fast component wear-out.