Car Mechanics (UK)

The ownership propositio­n and what goes wrong

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As the single-clutch automated manual gearbox needs more time to disengage the clutch and select the appropriat­e gear ratio, using its programmed software, the gear changes can seem ridiculous­ly ponderous to drivers more used to twin-clutch (Dsgtype) automated manuals, CVTS or even convention­al torque-converter automatic gearboxes. Sometimes, this can be improved by main dealer software updates, although it cannot alter the characteri­stics completely. For this reason, many drivers prefer to use a manual mode, so they can be sure that the transmissi­on has actually engaged first gear, just prior to the vehicle accelerati­ng from a standstill, for example. This is because some of the pre-programmed shift points are not always ideal for every real-life situation.

Driving techniques that may not damage torque converter-equipped automatic gearboxes, such as holding the car on a hill using the throttle, will cause rapid clutch wear in automated manuals, for the same reasons they do with a manual gearbox. Similarly, keeping the throttle pedal depressed fully when accelerati­ng and not backing-off during a gearchange can put the gearbox assembly under additional stress. While electronic safeguards are in place to cut the throttle on upshifts, full-throttle applicatio­ns can lead to a sudden and jerky clutch reengageme­nt. Car-makers will insist that the transmissi­on is designed to tolerate this punishment – presumably until the warranty expires, that is.

While the manual gearbox part of the system tends to be reliable, the automated components tend not to be as dependable. Problems vary between different applicatio­ns, but, generally, the clutch and gear actuators fail, as do the electronic control units (ECUS) that control them. The results can range from the car selecting only certain gears, to suffering a complete loss of drive.

As most problems are related to the electronic hardware, we consulted ECU Testing of Heanor, Derbyshire, which has developed its own test rigs and bespoke repair methods for the most common automated manual gearboxes on the UK market. While a DIYER might be able to conduct some basic repairs at home, the actuators can be removed quite easily and posted to a suitable mail-order specialist for testing, or repair. The cost of this will be considerab­ly less than at a main dealer workshop, which tends to advocate replacing complete components, the price of which can exceed four figures quite easily. For an older car, the final invoice can exceed the car’s market value.

To demonstrat­e typical dismantlin­g, testing and overhaulin­g techniques, ECU Testing advised us on Vauxhall’s Easytronic system, which is not only one of the most common systems on UK roads but is also prone to several specific faults.

 ??  ?? The interior of a single-clutch automated manual gearbox is virtually identical to that of an equivalent manual transmissi­on. Pictured is the selector shaft on a Vauxhall Easytronic unit.
The interior of a single-clutch automated manual gearbox is virtually identical to that of an equivalent manual transmissi­on. Pictured is the selector shaft on a Vauxhall Easytronic unit.

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