How long is a clutch?

Sometimes you come across the oddest cases quite by accident, and this one is no exception.

Whilst carrying out an investigation for a garage into a mysterious appearance of chassis damage - in the immortal words of Michael Flanders "which I'll tell you all about - some other time.", it was necessary to visit the garage on several occasions in order to gather all the information I needed for my report.

One day when I was there, I noticed a Renault Clio with the gearbox removed. There were chunks of metal missing from the clutch housing. "Looks interesting" I said to Alan, the proprietor of the garage. "Certainly is" he replied "the lady has only had the car three weeks and the clutch has literally exploded taking out the gearbox casing." We chatted about it for a few minutes, and being a bit inquisitive, I had a good look at the components which had been removed. The flywheel had turned blue with the heat, the friction linings from the clutch centre plate were virtually non-existent. The owner of the vehicle was in for a fairly hefty repair bill.

I thought no more about the vehicle and concentrated on the work in hand. About two weeks later Alan telephoned me. "Can you" he asked "come over right away, there is something I want you to see?"

You don't need a second invitation like that. I went immediately to the garage, and there was the same Renault Clio. "We delivered it back to the customer just over a week ago and today we have recovered it from the next village. It has lost all drive." Alan asked me to carry out an investigation and report so that he could then go back to his customer with full details of what had gone wrong.

He was certain in his own mind that there was no fault with any of the work which he had carried out on the vehicle. All the replacement parts had been obtained from the Renault main dealer. The customer in question was a lady in fairly advanced years who had, in her own words, "Driven any number of cars in most parts of the world:" I gathered from Alan that she had a somewhat imperious attitude, although that was not the exact word he used. Fine, no problem, let the investigation begin.

The gearbox was removed in order to gain access to the clutch. When it was removed, I could not quite believe my eyes. The shredded fabric of the clutch centre plate linings had crept out through the pressure plate release fingers. Very delicately, all the components were removed, placed on coloured paper and photographed.

Had I not seen this with my own eyes I would have been hard pressed to believe the condition of the parts. The flywheel was once again blue as a result of the heat generated, and the friction linings were almost non-existent. There was little doubt that the clutch had suffered from severe slippage.

"Does your customer have three feet?" I asked Alan. "One for each pedal?"

"Not that I am aware." was his reply.

I wrote my report and sent it in. In the report I ventured to suggest that maybe a car with automatic transmission might be a better option for the future. I had suggested to Alan that if that was not accepted as a solution, then maybe he should buy Renault clutches and flywheels in bulk!

You may imagine that the owner did not take too kindly to the report. The opinion expressed was that the garage and the Consultant Engineer were talking rubbish. Another clutch and flywheel were fitted, and the car was returned to the customer on the Friday afternoon. Saturday morning the telephone rang. It was Alan. "Come immediately." was his short but imperative message. Half an hour later I was there, and guess what - so was the Renault!

"We delivered this yesterday." Alan said, "and this morning we had a `phone call from the owner who was in the next village saying the car wouldn't move!" The clutch/gearbox casing was still too hot to touch without some discomfort.

There was only one thing for it - talk to the owner.

You may well realise that in taking this supposedly easy and simple step there is a distinct health hazard. Nobody admits to being a bad driver - certainly not someone who has "Driven any number of cars in most parts of the world." With a certain amount of caution we asked the owner to show us the gear lever positions for the relative gears. This she did, but not with much good grace. "First" she announced in a very clipped and terse manner. "Second and third." she said in the same tone.

Alan and I looked at each other. Which one of us was going to speak first. It was a bit like Bernard Woolley in "Yes Minister". "Ah, um, er you see that was actually third, fourth and fifth gear." A deafening silence ensued.

You can almost picture the scene when the vehicle left the owner's house up a slope to the road. It must have resembled a Boeing 747 on take-off. Goodness knows how many thousand revs. from the engine whilst the clutch must have been nearly incandescent!

Subsequently, I gather that she changed the car for an automatic, and to date all appears to be well.

So how long is a clutch? In the case of the last one fitted to this vehicle, 24 miles.

Douglas Wragg FIDiag.E

Douglas is a Road Transport Consultant Engineer