The rubber mountings that help to prevent engine vibrations from being transmitted to the bodyshell can actually cause vibration if they are damaged or softened by leaking oil. The weakened rubber allows the engine to rock excessively, and the engine and transmis- sion judders when the clutch is engaged.

To change a mounting under the engine or gearbox, a pillar or trolley jack is used to take the weight while the old mount- ing is undone. The engine or gearbox is then lifted, the old mounting removed, and a new one inserted.

Step 1. Place a jack under the engine sump. Put a piece of timber at least 1 in thick and measuring about 9in x6in on top of the jack.

2. Raise the jack until it just takes the weight of the engine. The timber will spread the load and prevent damage to the underside of the engine.

3. Remove the nuts or bolts securing the damaged mounting.

4. Slowly raise the engine, watching that the radiator hoses do not over-stretch, and that an engine-driven fan does not move dangerously near the radiator. If the hoses show signs of strain, drain the cool- ing system and remove them (see Project 7). Remove the radiator or fan if necessary.

5. Remove the mounting and insert the new one, putting on the mounting nuts or bolts finger-tight.

6. Lower the engine slowly. When the weight is on the mounting, fully tighten the fixings.