Rover Owners' Club Inc.

Rover Owners ' Club member Jim Moule has a P4 Cyclops.  Jim has developed a very good repair for the flexible drive on the starter motor on P3 and P4 cars.   The  procedure to repair the drive is made a lot clearer by the series of colour photographs Jim has provided.   The procedure was published in the March issue of the Rover Owners' Club magazine, Freewheeling, and is reproduced again here, in colour, for your information.

Making a Flexible Drive For A P3 / Early P4 Starter Motor.

By: Jim Moule

The P3 and early P4 model cars and Series 1 Land Rovers were fitted with a Lucas starter motor that had a flexible drive in place of the Bendix spring. My guess is that Bendix springs broke so the company decided to replace them with rubber. This was, in theory, a good idea and all Lucas starters of that period that I have seen are fitted with such a drive.

The rubber drive consists of two concentric tubes with rubber filling the gap between them. When the starter motor engages the cog into the teeth on the flywheel, the impact is softened by the flexibility of the rubber.

In practice, especially as the car gets older, the device is a source of trouble. The rubber perishes after being subjected to years of being bolted to a hot, oily engine. The rubber tears or separates from the metal tubes.

I wrote last year about a plan that I had to remanufacture a batch of these drives using polyurethane instead of rubber. Polyurethane is more resistant to heat and oil but still has enough flexibility for the job.

I sourced a polyurethane suspension bush of the correct dimensions. It happens to fit a Toyota Land Cruiser (knew that they would be good for something one day) Nolethane Part 47005 (pack of 12).

The first step is to get all the rubber out of the old drive so that you have two very clean tubes. The bush needs to have the flange cut off. It is better to have the bush too short than too long. Use Loctite 480 glue which sets very quickly and is impossible to get off your hands. Coat the outer curved surface of the bush and the inner surface of the larger tube and press home the bush so that its ends do not protrude into the castellated sections of the tube. Leave to strengthen overnight.

The hole in the bush is a little too small to take the inner tube. It is always the inner tube that breaks away so it is important for this to be a tight fit. Once the bush is inside the larger tube, the hole becomes even smaller so I found it necessary to bore it out a little with an electric drill. I ran the drill forwards then backwards until I could see that it was having some effect on the tough polyurethane.

Finally, coat the outer surface of the inner tube and the inside of the hole in the bush with glue and press the bush home so that the plain end is about flush with the end of the bush at the more deeply castellated end. The end of the inner tube that has little teeth should now be quite clear of the outer

A batch of these that is still being sold around Australia has the inner bush pushed too far in, so that there is not enough grip on those inner tube “teeth” when the drive is fitted to the starter motor. These sell for about $70 and are unusable. My determination to make a batch of these drives came from being sold one of these dud drives on Ebay.

If you try to make one of these bushes, you will probably fail, as I did. It took me three attempts before I was satisfied enough to fit the drive to a starter. So far, the drive has worked without a problem.

If your old drive breaks, don’t throw it away. I will exchange one of my rebuilt drives for $10 plus postage.

Contact Jim Moule on