Dismantling of the Fan Motors

One of the great things I’ve found about the restoration of the various electrical components is that they were designed in an era before our ‘throw away’ society. Therefore overhauling the units is well within the capability of most enthusiasts. As with the fuel pump, the stripping down of the fan motors was very simple.

Having said that, the fans had been attached the wrong way round and no matter what I tried they would not come free. I tried using a small, hub puller type tool on the first fan. However all this achieved was to shear the nylon fan from its central metal fixing, which then had to be carefully cut off using a Dremel tool. So two new fans were added to the ever growing shopping list of parts required!

The fan motor casing consists of a square steel body clamped between two alloy end plates. After the two long screws have been withdrawn, the end plates can be prised from the body with a screw driver. These Lucas motors weren’t designed to be watertight as the rear end plates have openings for the electrical connections. So, over time, water ingress had taken its toll on the interior components.

As the fan was still attached, the rotor (or armature), the front end plate and fan had to be removed as one. The only other parts within the motor are a wound stator and the armature brushes mounted in a plastic holder. The holder can be withdrawn by removing the two screws on the underside of the motor body.

The stator can then be pushed out of the plastic holder. The brushes are loose fitting and can simply be pulled apart and lifted away from the holder. In the end neither fan blade could be removed intact. A Dremel with a cutting disc was needed to remove the metal fixing that remained stubbornly attached to the armature shaft. Once it had been removed the armature and front end plate could be separated.

A thrust washer sits between the front end plate and the armature. A similar washer isn’t necessary between the armature and the rear end plate. When the fan is operating, the fan blade produces a forward force on the armature pushing it towards the front end plate and away from the rear end plate. Therefore there is no load on against the rear end plate.