In the Mondeo models with a manual gearbox, the engine is separated from the gearbox with each gear change using a single-plate dry clutch – a solution that has been tried and tested many times over the decades. For those who do the work themselves, the single-plate dry clutch has, of course, the disadvantage that worn parts such as the driven disk or the clutch release bearing are not "in sight" in the event of repair. In the Mondeo, this requires separating the gearbox from the engine and dismantling it: work that requires serious knowledge and special tools. Our advice: it is better to delegate the work of replacing the clutch to a specialist workshop.
Teamwork
the clutch consists of a flywheel 1, a clutch disc (driven disc) 2 and a clutch pressure plate (automatic clutch drive) 3. In all Mondeos with a manual transmission, the clutch pressure plate has a diaphragm spring. |
Clutch in detail
Engine flywheel: rotates together with the crankshaft and is firmly connected to it.
Clutch disc (driven disc): is located on the input shaft of the gearbox and rotates with it, it can move longitudinally. Friction pads are riveted to both sides of the "steel disk". The outer diameter of the clutch disc in the Mondeo, depending on the engine used, is different: 1.8 l / 2.0 l Duratec-HE = 228 mm; 2.5 l Duratec-VE/DuraTorg-DI = 240 mm.
Clutch pressure plate (hydraulic clutch drive): is firmly screwed to the engine flywheel. Presses the floating clutch disc to the flywheel with the help of a disc spring.
Clutch release bearing: (in all Mondeo models it is built directly into the clutch slave cylinder). It is located axially and moves on the release shaft. It transmits the clamping force created by the clutch pedal to the disc spring of the clutch pressure plate. The clutch pressure plate is released as a result – the driven disk loses the clamping force on the engine flywheel.
Automatic control unit: in all Mondeo models, the hydraulically operated clutch automatically adjusts the prescribed clutch pedal clearance. Therefore, there is no need for cumbersome adjustment work. As soon as the clutch in your Mondeo slips, assume that it needs to be replaced or perhaps "only" the primary pressure valve is stuck.
Closed-loop hydraulic system: how the clutch works in a Mondeo
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TECHNICAL DICTIONARY |
How does the clutch work?
Clutch clearance: when the clutch pedal is not loaded, the distance from the clutch pressure plate is maintained by the clutch release bearing. Similar to the wear of the clutch disc, the clutch clearance always becomes smaller with increasing mileage: the disc spring of the pressure plate approaches the clutch release bearing. As soon as the bearing is "without clearance" adjacent to the disc spring, the pressure plate is released. The clamping force of the driven disc on the adjacent surfaces of the flywheel and the pressure plate is automatically reduced as a result. If the clearance can no longer be adjusted, the clutch can no longer transmit the engine torque to the gearbox without slipping – the engine flywheel does not touch the driven disc.
Disconnection: If you press the clutch pedal, the elasticity of the pressure plate is weakened by the clutch release bearing. It is released and – when the clutch is fully released – is removed: the driven disk rotates freely between the pressure plate and the flywheel.
Clutch engagement: when the clutch is engaged, the clutch control practically undergoes a "reverse movement" of the disengagement process. The released disc spring of the pressure plate gradually presses the driven disk against the flywheel. At this stage, the friction pads briefly slide on the flywheel and the clutch pressure plate. With the clutch pedal disengaged, the clamping force of the hydraulic drive is ultimately so great that the flywheel even stops and the connection between the flywheel and the pressure plate becomes a reality. Now the engine power is completely transmitted to the gearbox. |
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PRACTICAL ADVICE |
Clutch "killer"
The dubious reputation of a clutch "killer" hurries ahead of any motorist who quite calmly drives his carriage into a rage with a "howling engine" and a slipping clutch: clutch killers regularly stage "hot" dramas between the friction pads of the clutch disc, pressure plate and flywheel with their "heavy" pressing of the clutch pedal, as temperatures build up around the slipping clutch that quickly finish off the clutch disc and pressure plate.
A driver who constantly "parks" his foot on the clutch pedal while driving thereby pays for his comfort in equal measure with increased wear.
Another bad habit of the clutch "killer": instead of switching to idle and setting the handbrake (parking brake), he keeps his car on slopes or in front of a red traffic light in the set first gear, with the clutch and gas pedals "in the air". For this, not only the clutch will "thank" him, but over time also the clutch release bearing, as well as the crankshaft adjusting bearing.
If you don't like the clutch "killer", then before a red light it is better to disengage the clutch and set first gear only when the light turns yellow. And while driving, place your sole - between gear changes - next to, and not on, the clutch pedal. |
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