The starter motors used on Series Land Rovers use relatively simple technology. Problems encountered can usually be solved by basic DIY procedures. However, we tend to ignore this important item until it fails to turn the engine rapidly enough for it to start. Removing the starter motor and checking it every few years should form part of our primary health care plan for any Series Land Rover.
Diesel-engined models use a pre-engaged type of Lucas starter motor, whereas petrol models use an inertia mechanism to engage with the flywheel once the motor shaft starts spinning.
Need for sufficient current
For the starter to work it requires 100+ amps and this requires the battery to be well charged and all terminal connections to be tight and not corroded. It is also important that the engine earthing strap and its terminals be in good condition to allow the return of the high current to the battery. So if the starter motor struggles to turn the engine or it has either an integral or remote solenoid fitted that just produces a click sound on activation, then these are the things to check first. The battery also needs to be well charged and the older the battery gets the less able it is to produce the high current required. The temperature of the battery also has its effect as the warmer it is the more easily the chemical reactions in it can take place to produce the current. For vehicles that have the push button starter switch, the contacts in this switch can become soiled and significantly reduce the starter motor current.
Care should be taken with the petrol-engined starter motors
that have the main current feed wire secured at the rear of the motor casing. The stud to which this wire is attached is secured by the inner nut - the outer one secures the wire only. If the stud itself is loose, then a poor electrical connection will result and maybe even cause an internal short-circuit. So be careful when you are re-connecting the feed wire to the starter motor.
Starter lacks power
If all electrical connections are clean and tight and the state of the battery is good (headlights do not dim after 30seconds) then the problem may be with the starter motor brushes, brush springs or commutator.
For diesel-engined starters the solenoid must be removed before access to the brushes can be achieved. Petrol-engined Land Rovers just require the metal band at the rear of the starter to be removed. In either case, the brushes(there are 4 of them) can be lifted by means of a suitably bent piece of wire
and their free movement in their holders assessed. If they stick, then they can be cleaned with a petrol-moistened cloth of even smoothened with a fine file. The thick connecting wire buried in the carbon brush should not be visible at the worn end of the brushes and if it is, or is judged to be nearly so, then the brushes need replacing. To replace the brushes the old ones need to be unsoldered and new ones soldered in. A powerful soldering iron will be needed due to the thickness of the wire and the potential heat sink thus created.
A rare, but possible cause of lack of power is a dirty surface to the commutator (the copper contacts that the brushes touch onto). If the surface is not shiny but is blackened and\or pitted then rubbing carefully with fine glass paper can restore the surface.
Jammed starter mechanism
Diesel-engined vehicles have the pinion gear pre-engaged with the flywheel teeth. This means that the starter gear teeth do not become jammed with those on the flywheel.
For inertia type starter motors, it's possible that the starter pinion gear can become stuck in the flywheel teeth. This would result in starters with a solenoid just producing a click and others simply silence and no turning of the engine. The inertia type motors often have a squared end to the drive shaft (may need to remove a dust cap to see it) and turning this can release jammed pinion gear. Otherwise, putting the Land Rover in 2nd or 3rd gear (ignition off) and rocking the Land Rover back and forth can free it. If this happens frequently, then suspect either a) worn pinion teeth, b) worn flywheel teeth, c) loose starter motor mounting bolts or d) dirt on the screwed sleeve of the starter motor drive assembly. To decide which of these four possibilities is responsible, the starter must be removed and inspected. The pinion teeth will tend to wear quicker than those on the flywheel and it is easier to renew these than to replace the flywheel teeth ring. The pinion must be able to slide freely along the shaft and be returned easily by the spring. If the screwed sleeve has dirt on it then clean it carefully, but do not be tempted to lubricate it as this attracts more dirt to stick - it should operate perfectly well dry unless the spring has become weakened.
In the event of the jamming being the result of a backfire, then the starter pinion shaft may have become bent and a new armature/starter may be required.
Petrol-engined IIA & III Land Rovers have solenoids that just connect the electrical supply to the starter motor. If they have an internal fault they are not repairable - some solenoids have a manual over-ride button on the end and this can be used to check if the fault is within the solenoid or not.
Diesel-engined Series Land Rovers
have solenoids that physically connect the motor drive to the flywheel - similarly the solenoid itself is not repairable.
For inertia type starter motors, this will almost certainly be due to worn teeth on the starter pinion and flywheel. Pre-engaged type starters will rarely be noisey due to worn drive teeth as they are in contact with each other continously.
The starter pinion teeth tend to wear more rapidly than those on the flywheel so just changing the starter
pinion may be sufficient to cure the problem. Early starters had the drive gear held in position on the shaft by a nut and split pin. These are fairly straight forward to remove. Later models, however, have them retained by a spring clip and the large spring needs to be compressed before the clip can be accessed. A spring compressor is available at accessory shops to perform this task, otherwise it can be done by using a suitably sized metal tube and a vice.
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