How to change a clutch in eight steps

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Clutches have a pretty tough time of it. They’re one of the hardest-working components in any car, withstanding enormous amounts of pressure and heat, yet it’s a part you don’t really think about until it stops working.

When it does? You’ll know about it. A bad clutch – whether burnt out, distorted or just plain worn – could quickly make you fall out of love with your beloved classic car.

But changing your clutch needn’t mean a trip to the garage. With some time, the right tools and a bit of care, you can replace it yourself. Here’s how.

What is a clutch?

The clutch is a key part of a car’s transmission, connecting the engine to the gearbox. When you want to change gear? It helpfully disconnects via a handy hydraulic system.

A clutch comprises three main parts: the plate, which is made of friction material and transfers drive from the flywheel to the gearbox shaft; the pressure plate, which uses springs to push the clutch plate against the flywheel; and the release bearing, which moves the pressure plate and disengages the clutch when the pedal is pressed.

Changing the clutch involves removing the gearbox – and sometimes the engine – so it’s usually cost- and time-effective to replace all three items, especially as they tend to wear out in sympathy. So, here goes...

Step 1: identify the problem

It’s crucial that you know what’s wrong before diving into any repair job – especially if you have to pull the engine out to get at the problem.

Is the clutch grating when you change gear or slipping when you accelerate? The former could mean it simply needs adjusting rather than replacing, or bleeding to remove air from the system. 

Vibration at speed, on the other hand, could be an unbalanced propshaft.

Step 2: disconnect the slave cylinder

The slave cylinder helps to disengage the clutch by pushing a rod against a fork or lever when you press the pedal.

To change the clutch, you’ll either need to remove the slave cylinder or – if you’re leaving it in situ – disconnect the hydraulic feed.

To remove it, first take out the pin that attaches the slave rod to the clutch fork. Before undoing the feed pipe, clamp the flexi hose to avoid emptying the master cylinder all over your nice clean overalls.

Step 3: remove the gearbox

Gearbox removal usually involves unbolting the starter motor, prop, speedo drive and any chassis-based gearbox mounts.

And that’s not the end of the heavy lifting: be prepared to take the weight of the unit when it comes free of the engine – and handle it with care. A lot of cars have ’boxes with aluminium housings, which can be fragile.

Step 4: examine all parts

The clutch plate is grooved to dissipate heat, which has the handy benefit of showing wear: if it’s smooth, it’s worn out.

As for the pressure plate, it should be smooth and crack free, with tight-fitting springs. 

If your car has a roller release bearing, spin it and listen for any rumbles. And inspect the clutch fork and flywheel face for damage while you’re at it, too.

Step 5: install clutch and plate

Ready to replace? Do the clutch and plate first. The longer side of the spigot drive usually faces the pressure plate, with the shorter side facing the flywheel.

Be sure to check the flywheel and pressure plate for markings, as they’re often balanced as a unit.

Then use an alignment tool to centralise the plate, before torquing the bolts by hand – a pneumatic drive could strip the threads.

Step 6: replace bearing

There are two types of release bearing, both of which are made from carbon: a hard-wearing, low-friction surface that meets the pressure plate, and a roller, which lets the bearing face spin.

Most British classic cars use the former – which wears and should be replaced – but both are usually fixed to the clutch fork with spring clips. Top tip: always use new clips.

Step 7: check and assemble

Ready to put everything back together? First check the phosphor-bronze spigot bearing at the back of the crankshaft: it wears and isn’t costly to replace.

Either squeeze it out with grease and a shaft that matches the internal diameter, or drive it out with a chisel. Soak the new one in oil then gently drive it in. Easy.

Finally, double-check everything before offering up the gearbox. Carefully.

Step 8: bleed and adjust

To finish off, reattach the slave cylinder and bleed the system.

If you can rope in a helper, this next step is easier with two: test the clutch and, when you feel it working, set up the free play on the slave rod or master cylinder (or both, in some cars) to prevent the release bearing resting on the pressure plate.

Tighten any locknuts then give it a road test. Re-check the free play when the clutch is hot, check for leaks and, if all seems well, the job’s done. Congratulations!