One of the big reasons for buying Ava was that she has four wheel drive. Being bogged down on a muddy camp site is not appealing so I’m hoping 4wd will keep me moving.
It works like this. Ava has a mighty 2½ litre diesel engine situated transversely at the front of the vehicle and driving the front wheels. Power is taken from the final drive and transmitted via a prop shaft underneath the body to the rear wheels.
But it’s not so simple. Instead of having a single, plain propshaft from front to back there is an intermediate device called the “viscous coupling”. Here’s the whole shooting match:
The front section of the prop shaft is at the top, next to the hydraulic trolley jack, then comes the viscous coupling (with the central white marker on it) between its two bearings (with the other two, outer, white markers; these marks were used to keep the components lined up) and finally the second section of the prop shaft which connects to the rear axle.
I can see you’re ahead of me. “Why”, you’re asking, “is all this laid out on a garage floor instead of installed in Ava?” The answer is because the carrier which holds the viscous coupling to Ava’s underside was badly corroded, and the two bearings either side of the unit were badly worn. Also, the rubber doughnut that connects the propshaft to the transmission output was perished. This necessitated much welding of the carrier and the sourcing of replacement parts. Since parts are no longer readily available for vans of this age, it was necessary to take the shaft to a specialist dealer and find current parts that WOULD fit. In the end the bearings are from a Jaguar and the doughnut from a Peugeot. This set me back nearly £700, which is why things are progressing at a slow rate. Better to have the work done here electively than in an emergency in Poland (or wherever).
You can see more detailed images on the Picture Galleries page – click the Refurbishment thumbnail.