When you turn the key and you just get a clunk but no turning of the engine it may be time to overhaul the starter solenoid.
First before you do anything check that the small spade connector on the starter motor is tight as this is what tells the startermotor to fire so if loose or corroded this can cause issues. However if all is ok here then chances are that the starter motor needs an overhaul of some sort.
Rebuild kits are available on e-bay etc from this seller
Cost is about a tenner for a kit, which is a lot cheaper than a full refurb, but chances are it won’t need a full refurb.
This How to… article covers how to fit this kit. The kit itself comes with pretty good instructions but these photos might prove helpful along the way.
First of all remove the starter motor from the car.
Disconnect the battery earth first of all as otherwise you might short something out with a spanner. Then disconnect the starter motor power feed, and the small spade connector.
There are two bolts that secure the starter motor, one at the front/top is obvious. The other which is at the bottom/back is much more hidden and is often a nut and bolt arrangement rather than just the bolt on the top. Once it is removed that is by far the hardest part of the job I reckon.
On the end of the starter you’ll see 3 8mm bolts. Unscrew these and remove any wire retaining clip noting how it was fitted
Once removed the cap will pop off under spring pressure. If it doesn’t pop off then give it a bit of assistance. Note the fitment of the rubber seal.
Remove the central plunger assembly noting the fitment of the smaller diameter long spring. Swap this spring onto the new plunger assembly supplied with the kit.
Note the wear to the copper contacts which is what stops the starter from turning. Put this to one side for a moment.
Next if you look inside you’ll see two electrical contacts.
These also need replacing with new items from the kit. However you’ll need to re-use everything else originally present on the starter motor. Unscrew each contact in turn noting carefully which ways round all the components are fitted and in which order.
Then replace with the new copper contact the correct way round, making sure everything goes back in the same order.
You can compare the thickness of the new contacts with the old ones as the old ones tend to wear out giving the no start problem.
Repeat the process for the other contact which has a bolted electrical connection to the starter motor. Making sure you replace everything in the correct order.
Once this is done then the plunger can be placed back into the starter motor making sure the long spring is placed over the end of it first. Then replace the cap and ensuring that the rubber seal is in place, and replace the 3 bolts and wire retainer. Then replace the starter motor back onto the engine and finally reconnect the power and spade connectors for it. Then finally reconnect the vehicle battery. Test it and then that’s it, job done and you’ve saved yourself about £50 on a rebuild charge.