The starter motor of the Renault Duster is a four-pole, four-brush DC electric motor with permanent magnet excitation, combined with an electromagnetic two-winding pull-in relay.
The covers and the stator housing are held together by two bolts. Permanent magnets are secured in the stator housing.
The rotation from the armature shaft of the electric motor is transmitted to the drive pinion through the freewheel clutch.
When the key in the ignition switch is turned to position "D" (engine start), the voltage from the battery is applied to the pull-in and hold-in windings of the pull-in relay; as a result, the drive lever moves and the starter pinion engages with the ring gear of the engine flywheel.
Simultaneously, the armature of the pull-in relay closes the power contacts (at this moment the pull-in winding is switched off) and the voltage from the battery is applied to the starter electric motor.
The starter armature, through the freewheel clutch, turns the engine crankshaft.
After the engine starts, when the rotational speed of the pinion exceeds the rotational speed of the starter shaft, the freewheel clutch unlocks and slips, protecting the starter from high rotational speed and damage.
Removal and testing of the K4M engine starter motor
We prepare the vehicle for the work.
We place the vehicle on an inspection pit or a lift.
We disconnect the negative terminal of the battery.
We withdraw the oil dipstick.
We remove the fuel rail protection.
Using a 10 mm socket, we undo the nut.
We remove the cable terminal from the contact bolt of the pull-in relay.
Using an 8 mm socket, we undo the nut.
We remove the cable terminal from the control terminal of the pull-in relay.
The nut is secured on the cable terminal.
Using a 13 mm socket, we undo the upper starter motor mounting bolt.
We undo the lower starter motor mounting bolt (shown from underneath the vehicle).
This bolt also secures the wiring harness holder bracket.
We remove the starter motor.
We check the starter motor drive.
Using a screwdriver, we turn the drive pinion.
The pinion must turn in one direction with the drive shaft and in the other on the drive shaft. Otherwise, the drive must be replaced.
Using a screwdriver, we move the drive pinion along the shaft.
The pinion must move along the shaft easily, without jamming.
To test the starter motor, we connect with wires: the positive terminal of the battery to the upper contact bolt 1 of the pull-in relay, and the negative terminal to the starter motor housing.
Using a screwdriver, we bridge the upper contact bolt 1 and the control terminal 3 of the pull-in relay.
The drive pinion should then extend and the starter electric motor should run.
Otherwise, we check the electric motor and the pull-in relay of the starter.
To test the electric motor, we connect with wires the positive terminal of the battery to the lower contact bolt 2 of the pull-in relay, and the negative terminal to the starter motor housing.
The electric motor shaft should then rotate.
Otherwise, the electric motor is faulty.
To test the pull-in relay, we connect with wires the positive terminal of the battery to the control terminal 3 of the pull-in relay, and the negative terminal to the starter motor housing.
The drive pinion should then extend.
If this does not happen, the pull-in relay is faulty.
We install the starter motor in the reverse order.
The locating pin on the clutch housing should then enter the corresponding opening in the front cover of the starter motor.
Removal and testing of the F4R engine starter motor
We disconnect the negative terminal of the battery.
We remove the power unit protection (article — Removal of the engine protection, wheel arch liners and mudflaps).
We remove the air intake with the resonator as an assembly.
Using a 13 mm socket, we undo the two starter motor mounting bolts.
We withdraw the bolts.
Location of the bolts.
Using an 8 mm socket, we undo the nut securing the cable terminal to the control terminal of the pull-in relay.
The nut is secured on the cable terminal.
We remove the cable terminal from the relay terminal.
Using a 10 mm socket, we undo the nut securing the cable terminal connected to the positive terminal of the battery.
The nut is secured on the cable terminal.
We remove the cable terminal from the contact bolt of the pull-in relay.
Using a 13 mm socket, we undo the lower starter motor mounting bolt.
We remove the starter motor.
We check the starter motor drive.
Using a screwdriver, we turn the starter motor drive pinion.
The pinion must turn in one direction with the drive shaft and in the other on the drive shaft.
Otherwise, the drive must be replaced.
Using a screwdriver, we move the pinion along the shaft.
The pinion must move along the shaft easily, without jamming.
If the pinion jams on the shaft, the drive must be replaced.
To test the starter motor, we connect with wires: the positive terminal of the battery to the upper contact bolt of the pull-in relay, and the negative terminal to the starter motor housing.
Using a screwdriver, we bridge the upper contact bolt and the control terminal of the pull-in relay.
The drive pinion should then extend and the starter electric motor should run.
To test the electric motor, we connect the positive terminal of the battery to the lower contact bolt of the pull-in relay, and the negative terminal to the starter motor housing.
The electric motor shaft should then rotate. If this does not happen — the electric motor is faulty.
To test the pull-in relay, we connect the positive cable of the battery to the control terminal of the pull-in relay, and the negative terminal to the housing.
The drive pinion should then extend.
If this does not happen, the pull-in relay is faulty.
When installing the starter motor, we first place the cable terminals on the contact bolt and the control terminal of the pull-in relay and start the nuts of their securing.
We install the starter motor in place and start the three bolts of its securing.
The locating bush 1 in the clutch housing must enter the opening 2 in the front cover of the starter motor.
After this, we finally tighten the starter motor mounting bolts and the nuts securing the cable terminals.
We install all parts in the reverse order.
Disassembly of the starter motor
Using a 13 mm socket, we undo the nut.
We remove the cable terminal from the terminal of the pull-in relay.
Using a Torx T-25 key, we undo the three screws securing the pull-in relay.
We remove the pull-in relay.
We withdraw the spring from the pull-in relay.
Using a 7 mm ring spanner, we undo the two clamping bolts.
We separate the front cover and the starter motor housing.
We withdraw the seal.
We remove the front cover.
We remove the drive lever.
We remove the pull-in relay armature from the drive lever.
We remove the drive assembly.
We withdraw the armature with the brush holder from the starter motor housing.
Using a cross-head screwdriver, we undo the two screws.
We remove the cover.
We withdraw the retaining washer from the groove of the armature shaft.
We remove the spacer washer.
We remove the rear cover.
We remove the brush holder.
We remove the insulated brushes from the brush holder.
Using a screwdriver, we prise off the cover.
We remove the planetary gear reducer cover.
We withdraw the three planetary gears of the planetary gear reducer.
We rest the end face of the ring gear on a wooden block.
Having placed the jaws of a 12 mm open-end spanner on the limiting ring of the drive pinion travel and struck the spanner with a hammer, we press off the limiting ring.
We prise with a screwdriver.
We remove the locking ring.
We remove the limiting ring.
We remove the freewheel clutch with the drive pinion as an assembly.
Using a screwdriver, we move it off the groove.
And we remove the retaining ring.
We move the washer off the drive shaft.
And the ring gear of the planetary gear reducer.
We inspect and check the condition of the commutator and the armature windings.
Charring of the windings is not permitted.
The ends of the windings must be well soldered to the commutator segments.
In case of slight burning of the commutator, we clean its segments with fine abrasive paper.
Using an ohmmeter, we check the armature winding for a short to earth.
The resistance must be very high (tending to infinity).
We replace the faulty armature.
We inspect the brushes; they must not have cracks or chips. Otherwise, we replace the brush holder with a new one.
We assemble the starter motor in the reverse order.
We mount the brush holder before installing the armature into the starter motor housing.
Before installing the brush holder on the armature commutator, we push the brushes into the guides and insert the mandrel 1 into the central opening of the brush holder.
We can use a socket with an outside diameter of 30.5 mm.
Pressing the mandrel against the commutator, we move the brush holder off the mandrel onto the commutator.
We install the rear cover, the spacer and retaining washers and close them with their cover.
We install the rear cover so that the protruding part of the cover aligns with the rubber seal of the brush leads.
When installing the starter motor housing onto the armature, we hold the armature with the hammer handle to prevent it from being attracted by the permanent magnets of the stator and lower the housing onto the rear cover.
