Recently, the big tree underneath whose branches we usually have our lunch witnessed an animated discussion. Japie asked each of us to name the toughest car built since WW2.
I opted for the 123-series Mercedes-Benz models that can still be seen in their thousands all over Africa and the Middle East. Hennie selected the Toyota Camry that was the first foreign car to outsell the Yankee models in their own country. Syd pointed out that the Mazda 323 deserves an honourable mention, and Japie chose the 1200 and 1400 Datsun/Nissan range of cars and bakkies.
This explains our surprise when Ray Hoffmann, our happy-golucky artificial inseminator, pulled into the forecourt with his welltravelled Camry. “I’m glad I made it here,” were his first words. “The gearbox has been noisy for some time, but it now feels like its going to give in completely, especially when cornering.”
Hennie took the wheel, but came back very quickly to tell us that the car is almost undrivable, and proceeded to the workshop. About an hour later the transmission and final drive parts were laid out for inspection.
It was plain that the spider gears were unbelievably loose on their shafts, but the other components did not show any excessive wear. These gears only work during cornering or when wheelspin takes place, and since Ray wasn’t that kind of driver we new that something else must have caused the excessive wear.
We all put on our thinking caps, but by the next morning nobody had offered any explanation. Japie did remark that the Camry seemed to have been used as a 4×4, to judge by the grass seeds in the radiator and underneath the car, and Koos, who knew the owner well, said that Ray was not overly bothered about keeping the Camry in good condition, because inseminators often have to travel on very bad roads to get to their clients.
I went out to have another look at the car, and spotted something weird. The left-hand and right-hand tyres had different profiles, and hence different running circumferences.
Could this cause excessive spider gear wear? I contacted a friend who runs a gearbox repair centre, and he confirmed that the different tyre diameters would force the gears to rotate continuously, resulting in the wear we were viewing.
A new differential unit would be expensive, but Ray can afford it. Koos told me that he’s so casual with money that he sometimes leaves cheques in the car’s cubby for so long that they eventually run out of date!