How to recognise it
The engine revs climb without the car accelerating, most noticeably in 4th, 5th or 6th gear, under load, towing or on hills. You may smell a hot, burning smell after a long climb. The bite point often feels higher than it used to.
Worn clutch
On an older clutch the friction lining wears thin and can no longer hold full engine torque. It usually shows in the top gears first, because that is where the load on the clutch is highest.
Oil or grease on the clutch
A leaking rear main seal or gearbox input shaft seal, or too much grease on the input shaft splines, can contaminate the friction disc so it cannot grip, even if it is new.
No free play or a hydraulic fault
If the pedal has no free play at the top, or the master cylinder or slave cylinder is not fully releasing, the system stays slightly pressurised and the clutch is never fully clamped. This is a common cause of slipping soon after a new clutch is fitted, and the pedal free play and bite point are worth checking first.
What to tell the mechanic
Which gears it slips in, whether it happens hot or cold, when the clutch was last replaced and what was fitted with it (flywheel, slave cylinder), the bite point, and any burning smell or leaks under the bellhousing.
Safe to drive?
A slipping clutch gets worse quickly and the heat can damage the flywheel and pressure plate. Avoid hard acceleration, towing and highway driving, and book it in soon.
General guidance only, not a diagnosis. If in doubt, do not drive it and have it inspected. In an emergency, call 111.
Who can help
Get quotes for transmission & clutch repair near you
Questions
Can a brand-new clutch slip?
Yes. Contamination, a hydraulic or pedal adjustment fault, or the wrong parts can all cause it. The installer should check pedal free play and the hydraulics before anything is stripped down.
Is it the clutch or the automatic gearbox?
A manual car slips at the clutch. In an automatic, flaring revs between gears is a transmission fault, see the gearbox guide.