How To Change Rubber Mountings in a Car Engine and Manifold Gaskets

HOW TO CHANGE RUBBER MOUNTINGS IN A CAR ENGINE

The rubber mountings that help to prevent engine vibrations from being transmitted to the body shell 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 transmission judders when the clutch is engaged.

To change the mountings under the engine or gearbox, a pillar or trolley jack can be used to take the weight while the old mounting is undone.

The engine or gearbox is then lifted, the old mounting removed, and a new one inserted.

1. Place a jack under the engine sump. Put a piece of timber at least 1in thick and measuring about 9in x 6in 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 cooling system and remove them. You can remove the radiator or fan if it becomes 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.

HOW TO FIT A NEW STEADY-BAR RUBBER BUSHES

Worn steady-bar rubbers will allow an engine to rock excessively, causing clutch judder and putting an unnecessary strain on the exhaust system. The illustrations show how the job is done on a mini.

1. Remove the fixing bolt and loosen the cover bracket bolt on the cylinder head.
2. Swing the steady bar clear and pushing the old rubbers from the eye.
3. Fit the new rubbers and sleeve by hand. If they are difficult to fit, coating them in the washing-up liquid will help them into the eye.
4. Fit the center sleeve re-assemble the bracket and fixing bolt and tighten both bolts.

HOW TO CHANGE THE GASKET OF AN EXHAUST MANIFOLD

If an exhaust manifold gasket leaks, usually because a nut or bolt has worked loose exhaust fumes may drift into the car. A leak makes a distinct chuffing sound and the hot escaping gas can be felt with the palm of a hand.

Renewing the gasket can stop the problem. Some cars have their inlet and exhaust manifolds combined, in such cars; the carburetor air filter must be removed and it may become necessary to disconnect the throttle and the choke controls at the carburetor if they are anchored to the manifold.

Below are the steps to take in doing that:

1. If the manifold has never been removed, penetrate oil on the fixing bolts or nuts and leave it overnight to work into the threads.
2. Remove the nuts or bolts securing the manifold using a socket and extension or a box spanner if it becomes necessary.
3. Move the manifold away from the cylinder head and extract the old gasket. In a few cars, the downpipe to the exhaust system will restrict the movement of the manifold. On these, loosen the clamp between manifold and downpipe.
4. Scrape off all traces of old gasket material from the manifold and head faces.
5. Insert the new gasket, refit the manifold and do up all fixings finger-t0ight. Then tighten them firmly with a spanner or socket, working outwards from the center.
6. If the downpipe joint has been loosened, re-tighten the fixings. Reconnect throttle and choke controls, and refit the air cleaner if it has been removed.