Time to brush up.

(T-Cap partner article)

After a few hundred thousand kilometres your trusty old Toyota might begin to show some difficulties when starting-up.

Has the starter motor – that vital component that keeps your pride & joy purring - just given up the ghost? Perhaps it's not broken – what if the carbon brushes are just worn out?

1. What's a starter motor?

The starter is an electric auxiliary motor powered by the battery that serves to crank the engine at start-up.

Many different models exist according to engine type and manufacturer but today we're going to have a look at the model fitted to D4D engines found in KZJ, KDJ, 4 Runner and other Hilux vehicles.

2. Tools.

You don't need a fully equipped workshop to change your starter motor brushes but you will however need at least the following:
- A few flat spanners.
- A large crosshead screwdriver (N°2).
- A file.
- A high temperature soldering iron (if not a small gas blow torch).
- Suitable tin flux and primer.
- Hampton paste (or any other brand of de-oxidizing paste).
- A set of new carbon brushes that will cost you roughly 10 € from Euro4x4Parts.

3. Dismantling.

Dismantling the starter motor is not very complicated in itself because not everything needs to be stripped. For this particular model only the motor (armature, coil) can be removed. Start off by opening the bonnet (makes things easier) and disconnect the batteries.

Warning: A starter motor requires high power electrics. The cable cross sections are big and a short circuit can easily happen. Always disconnect your batteries to avoid vehicle damage and the risk of burns or fire.

Locate the position of the starter motor (below the oil filter). A wire connects the starter to the engine. First step is to disconnect this by unscrewing the wire from the starter. The wire remains connected to the engine. Unscrew the two long bolts that hold the motor to the starter housing (see arrow in diagram). The motor should then slide out by itself.

Having removed the motor you can head over to your bench.

The photo clearly shows the position of the two bolts that hold the motor.

4. Changing the carbon brushes.

a. Dismantling.

Start off by cleaning the outside of the motor casing – if you off-road then this won't be too soon! The coil can be removed at this stage so as not to hinder operations later.

Next remove the rear cover by unscrewing the two crosshead screws. Clean the screw heads well to avoid nasty surprises. An impact screwdriver is recommended to avoid damaging the heads.

Remove the cover to reveal this:

To separate the brush holders from the armature you need to remove the two springs that hold the brushes fixed onto the armature. Use a small screwdriver, carefully avoiding damage to the springs.

b. Soldering.

Cut the two brush wires next to the armature using wire cutters. As a rule these will have been factory fitted using an electric arc-welder, so it's not easy to just “de-solder” them.

Use a small flat file to clean the copper base where the brush was soldered.

Next use the soldering iron to heat up the copper base and cover it with a drop of flux. You can also add a drop of Hampton grease to improve contact.

Do the same to the end of the wire on the new brush, and then join the brush to the base. Carefully solder and check the strength of the join. Repeat this process for the second brush.

For the brush holder it's the same steps:
- Cut off the old brush
- Clean and file the point of contact
- Solder in the new brush.

Once again it's the quality of your soldering that will determine how well your starter will then work.

c.Checking the coil.

Having dissembled the starter take the opportunity to have a look at the coil. Clean and grease the gearings and check the windings.
Using a voltmeter check the resistance continuity between each contact. And also check that they haven't been overly worn by the rubbing action from the brushes.

5. Reassembly.

Reassembly of the starter motor is pretty straightforward. Just work backwards step-by-step.
Start off by putting the brush holder back in place on the armature with the two brushes pushed back in position. Refit the coil whilst separating the brushes. Now screw down the cover having added a spot of grease to the gearing.
Mount the motor back on the starter casing that remained on the vehicle. Secure into position using the two long screws with run straight through from one end to the other.
Reconnect the wire to the starter body. All that remains is to reconnect the batteries before testing by starting-up.

6. Conclusion

Given that a your friendly Toyota dealer charges almost 800 € (excluding labour of course!), changing your carbon brushes by yourself using a Euro4x4Parts kit is a financially rewarding challenge, well within reach of the average home mechanic. Of course with the 790 € left in your pocket you can now treat yourself to a return trip to Africa to take your rejuvenated starter motor out for a spin!
Euro4x4parts can also supply starter motors to less adventurous mechanics for about 400€. That's still half the price from the main dealer!