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Frequently Asked Questions
Why are clutches sold and fitted as kits?
Because the labour to reach them dwarfs the parts, and the three main components wear together - so replacing one means doing the same job again later for the others.
The gearbox has to be removed to reach any of the disc, the pressure plate or the release bearing. That access cost is identical whether one part is replaced or three.
The three also share a service life, because they have all done the same work for the same time.
A new disc against a worn pressure plate gives reduced clamp load and a clutch that slips early, which reads as a faulty new part.
A reused release bearing is the worst case of all: it is the cheapest item in the kit and the most common cause of a repeat job.
Kits typically include an alignment tool, which is not optional - a disc fitted off-centre will not allow the gearbox to seat.
What else should be replaced while the gearbox is out?
The spigot bearing, the release fork and pivot, the concentric slave cylinder if fitted, and any oil seal that is weeping.
All of these are inexpensive and all become inaccessible the moment the gearbox goes back in.
The spigot or pilot bearing supports the gearbox input shaft. A failing one produces noise and misalignment and is trivially cheap.
The release fork, its pivot and any plastic bushes wear and are a common source of a heavy or notchy pedal.
A concentric slave cylinder lives inside the bellhousing. On vehicles with one, it must be replaced with the clutch as a matter of routine, not judgement.
Oil contamination on a clutch disc comes from the crankshaft rear main seal or the gearbox input shaft seal. Fitting a new clutch without curing the leak guarantees the job comes back.
How do I tell slipping from dragging?
Slipping is engine speed rising without the vehicle accelerating; dragging is the vehicle still being driven with the pedal down.
Slip is a friction problem: worn facings, oil contamination, or a pressure plate that has lost clamp load. It shows first in high gear under load, such as pulling away up a gradient.
A quick test is to pull away in a high gear with the handbrake on. A healthy clutch stalls the engine; a slipping one does not.
Dragging is a release problem: the clutch is not fully disconnecting. It shows as difficulty selecting first from rest, or a graunch into reverse.
Dragging is very often hydraulic rather than mechanical - a failing master or slave cylinder, or air in the line - and those are far cheaper to fix than a clutch.
Check the hydraulics and the pedal free play before condemning the clutch itself. That check costs minutes and can save the whole job.
What causes clutch judder?
Uneven engagement - contamination, a distorted disc or flywheel, or worn mounts letting the driveline move.
Judder is a shudder felt through the vehicle as the clutch takes up, usually worst when pulling away gently.
Oil on the facings is the commonest cause, and it points at a seal rather than at the clutch.
A warped or heat-damaged flywheel face gives the same effect and is why the flywheel should be inspected, machined or replaced with the clutch.
Worn engine or gearbox mounts allow the whole driveline to rock as torque comes on, which presents as judder and has nothing to do with the clutch at all.
Dual-mass flywheels have their own wear pattern - excessive free play or rattling at idle - and a failing one will make a new clutch judder immediately.
Should a dual-mass flywheel be replaced with the clutch?
Check it, and replace it if it is outside the manufacturer's limits - which, at the age most clutches are replaced, it frequently is.
A dual-mass flywheel damps torsional vibration between the engine and the gearbox using internal springs, and those springs wear.
Its condition is measured as rotational free play and lateral movement against published figures. It is not a visual judgement.
Fitting a new clutch to a worn dual-mass flywheel produces rattle at idle, judder on take-up, and a repeat job.
Conversion kits replacing the dual-mass with a solid flywheel and a sprung-hub disc exist and are cheaper, at the cost of more transmitted vibration and, on some vehicles, noticeable rattle.
For fleets, the decision is usually made once per platform and applied consistently, because mixing the two on identical vehicles makes driver complaints impossible to interpret.
Is the noise the pedal makes diagnostic?
Yes - whether the noise appears with the pedal up or down separates the release bearing from the gearbox input shaft bearing.
A noise present with the pedal up and disappearing when it is pressed is usually the gearbox input shaft bearing, which is unloaded as the clutch disengages.
A noise that appears when the pedal is pressed is the release bearing, which only spins under load when the clutch is being released.
A squeal that changes with pedal position and not with engine speed is usually the pivot, the fork or the cable rather than a bearing.
Rattling at idle in neutral that stops when the pedal is pressed points at the dual-mass flywheel or a worn spigot bearing.
Whichever it is, all of them are inside the bellhousing, so the diagnosis determines urgency rather than access - the job is the same.
How long should a clutch last?
It is a duty-cycle item, not a mileage item - urban stop-start work can consume one in a fraction of the life the same clutch achieves on long runs.
Wear happens during slip, and slip happens when pulling away and changing gear. A vehicle that does both constantly wears a clutch quickly.
Load matters as much: a fully laden commercial vehicle slips the clutch harder and longer at every start.
Driving technique is the largest single variable, and riding the pedal or holding on a gradient with the clutch will halve the life.
For fleets, that makes clutch life a useful driver-behaviour indicator, and it is worth tracking by vehicle and by driver rather than by model.
There is no service interval and no inspection short of removing the gearbox, so the practical approach is symptom-driven replacement with the associated items done at the same time.