A CLUTCH
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By allowing only 10 minutes for an adjustment check during every routine service, operators could quadruple clutch life
• Most road transport operators will make sure that the engine oil in their vehicles is dipped each day before they go out on the road. Many will check other fluid levels and brakes. Few, though, will bother to look at clutch adjustment and linkages. Even if vehicles are being intensively used on a threeshift system around the clock, covering perhaps 320,0001an (200,000 miles) a year, it is unlikely that their clutches will be inspected even during routine servicing.
As a consequence of this neglect large numbers of operators are discarding clutches, because they may be slipping or owing to difficult gear engagement, when there is still a great deal of life left in them. That is the contention of Brian Perry, sales and marketing manager of Spicer Clutch and Power Products Division of Dana.
Spicer claims to be leader in the UK market for clutches for British trucks above 28 tonnes gross vehicle weight. Currently, more than 80 per cent of UKmanufactured, premium-weight trucks registered annually in this country have the West Midlands manufacturer's clutches fitted as original equipment. Total production at the company's Wolverhampton plant runs to nearly 16,000 units a year. Of these, 7,000 are sold into the aftennarket and most of that figure is made up of remanufactured units.
This is an expanding area of Spicer's activity, where it and other commercial vehicle clutch manufacturers (principally Lipe) are regaining ground held by "spurious" remanufacturers. These companies, which simply recondition and rebuild clutches made originally by manufacturers such as Spicer, now account for a share of the service market which has been diminishing and now stands at about 50%.
It is the discarded clutches that are reprocessed by Spicer which provide the evidence for Brian Perry's assertion that a large volume of clutches are being thrown away before they are life-expired. Many operators, he says, are getting only 80-95,000km (50-60,000 miles) from them when they could expect up to 320,0001cm (200,000 miles) from clutches with organic friction facings and twice that from cera-metallic clutches (whose sales now outsell organic Spicer units by more than two to one.
"So many clutches aren't even worn when they're changed," says Perry. He adds that with some cera-metallic plates which are returned to the factory as worn out have an even greater thickness of lining material on them than when they were fitted — as they bed in they grow by about 0.23mm (9/1,000in) across the clutch pack.
The reason for such apparent extravagence? "People don't understand clutches," says Perry simply. "Operators are frightened of them." This is particularly true, he adds, of cera-metallic clutches, which are often prematurely discarded simply because when the engine or gearbox has been taken out of a vehicle for repair the exposed clutch has shown apparent signs of burning. In fact, black deposits are normal with cerametallic clutches. They are simply particles of graphite from the sintered copper, iron and graphite compound of which cera-metallic linings are made. On their own they are no cause to suppose that the clutch is approaching the end of its life.
The prevailing attitude among operators towards clutches is, according to Perry, "Fit it and forget it." This could largely be a hangover from the days when self-adjusting clutches were at their peak of popularity.
That popularity may have declined — self-adjusting clutches now account for around 40% of clutch sales in the UK — but these units still have to be adjusted correctly in the first place. "Unfortunately, the common attitude seems to be 'bolt it on to the flywheel and send it out, "Brian Perry says.
The move away from self-adjusting units highlights an important element of how operators regard clutches in general. One reason for their decline has been that CV manufacturers now generally do not offer them as part of the standard specification of their vehicles, but, more significantly, they received a great deal of bad publicity for poor reliability. That has only added to the low expectancy operators appear to have of all types of clutch, although wear has been improving with the advent of twin-plate clutches and larger plates to cope with the trend in recent years towards increased power outputs from engines.
If ever there was a case for customer education it must surely be that concerning clutches. "The best anybody can do is understand the product," maintains Perry.
This is precisely what Spicer has been striving to do over the past few years. One of the mainstays of its campaign is a poster for workshop walls. The 600x420rnrn (2ft x 161/2in) chart explains concisely and with diagrams all of the necessary procedures for setting and adjusting clutches and linkages. Self-adjusting models are also included, and the poster also displays prominently bearinggap, slave-cylinder back-travel and brakesqueeze dimensions.
The chart is purely functional; not being decorative it is unlikely to find its way on to a wall in an executive's office where it would do least good. It is given away at exhibitions and similar events and is available from the company free of charge.
Since it was first published two years ago, interest in the poster has been strong. More than 2,000 have been dispensed and a reprint has been printed.
1n-company demonstrations are another important facet of Spicer's education campaign. The company's chief engineer, Larry Hopkins, two other engineers and Brian Perry himself are involved in these training sessions, In addition, they support training courses run by chassis manufacturers including Leyland and ERF.
There is no size limit regarding operators which qualify for a Spicer incompany clutch adjustment training session; requests from one-man businesses are just as welcome as those from companies with large lorry fleets. "All operators could benefit from our going and showing them," says Perry.
Ironically, Perry has found that it is with fleets that education is most needed. "The one-man operator often understands his vehicle better than the large haulier. After all, he signs the cheque that pays for the vehicle so he will take the time to look after it," he believes.
He adds: "Timing in large fleets doesn't lend itself to preventative maintenance. The big-fleet driver just drives and reports any problems with his vehicle to the workshop."
Exhibitions are used by Spicer as a third line of attack. The company is a regular attender at major CV shows and this year has taken part in exhibitions including Municipal Vehicles in Action, the Institution of Road Transport Engineers' recent Solihull display and the Road Haulage Association's Tipcon tipper show.
"We don't go to shows to sell," says Perry. "We go to talk to operators. We believe that we have to be at the major shows making ourselves approachable to operators."
There is usually no shortage of operators at these events with individual clutch problems to sort out — problems which are often the result of ignorance. This is frequently not the fault of the operator, says Perry. "Some vehicle manufacturers are sometimes slow in advising their customers of changes in specification which may affect clutch life,' he adds.
Slowly, Spicer's message that regular attention to clutch adjustment pays is get ting across, although clearly there is still work to be done. In the final analysis it it costs which are the basis of the most convincing arguments for taking proper care of clutches. Downtime due to insufficient clutch maintenance could cost an operator as much as £1,000 in terms of hours off the road when a vehicle could be earning, and anything from six to 18 hours of mechanics' time to replace a faulty clutch.
It surely makes sense, therefore, to avoid such expenditure by getting two mechanics to spend about 10 minutes to go through a simple series of clutch checks about once every two weeks for intensively-used vehicles. The reward if they do, says Brian Perry, is that there "should not be a clutch failure until the unit is worn out — and a clutch should n( be worn out until it can no longer be adjusted." El