REPXPERT Alistair Mason answers Aftermarket questions


REPXPERT Alistair Mason answers Aftermarket questions
  • Aftermarket November submission
  • Clutches & transmission. feature
HEREFORD, 3rd October. Engines are changing, so the clutch and transmission system is being adapted too. All the latest on technology and methods.

*What’s new in the world of clutch and transmission?
“Manual gearbox cars are still very popular, so there is still a high demand for clutch repairs and replacements. The number of vehicles using self-adjusting clutches continues to increase, as they give the benefits of a lighter clutch operation with a consistent bite point and a consistent clamp load.

“We are now seeing the use of hydro-electric clutches in semi-automatic transmissions, where an electrical actuator controls hydraulic pressure to the concentric slave cylinder to operate the clutch. A position sensor is fitted to the slave cylinder to give feedback on the clutch position.

“The future is in electrically-controlled clutches, which will also help reduce vehicle emissions, allowing the car to coast wherever possible (Figure 1 attached).

“Double clutch systems are also now being used by most vehicle manufacturers (VMs). The main advantage is the gearchange speed – which can be as quick as .08 seconds! Because of this, when accelerating, drivers tend to hold the throttle in one position until the desired speed is reached, and then they lift slightly to maintain that speed. As a result, it is lot easier for the vehicle to run at Lambda 1 to aid emissions control and, because the gearbox is controlled by an ECU, it is always in the correct gear. The dry double clutch system is the most efficient as there is no drag on the clutch.”

*With vehicles becoming more efficient, how important is for clutch and transmission systems to be maintained properly?
“Generally, the only maintenance required on the transmission system are oil changes on automatic, wet double clutch and constantly variable gearboxes. This is because the oil becomes contaminated as the clutch wears, losing its lubricating properties as it deteriorates, causing premature wear on associated components, leading to expensive repair bills.

“Another area to look at, to ensure gearboxes are maintained properly, is the control unit software. VMs are constantly modifying software to optimise systems and prevent potential problems.”

* What are the options for garages when sourcing parts to please customers?
“My first piece of advice in this area would be to fit quality parts from a known manufacturer, not simply choose on price. It is the workshop’s reputation at the end of the day, and if rectification work is required due to faulty parts, who’s going to pay? There’s also going to be an unhappy customer.
“I’d also recommend not ‘mixing and matching’ parts during a clutch replacement – use all components from just one brand as they will be optimised to work together. If the flywheel is also being replaced, again use the same brand. We have seen many problems arising from mixing different branded components.

“I would also use a reputable and trusted supplier; if there are any problems they can then be quickly and easily resolved and advice given if required. Sometimes, workshops need support, and we also have to remember there is a vehicle owner paying for the work at the end of the day.”

*Tips and tricks?
Spend 10 minutes researching the job; special processes are becoming more common these days, mistakes can be costly. Software updates can resolve a lot of faults on cars, so these are always worth checking before removing major components.

Use the correct tools; tolerances are a lot finer these days and components are more sensitive. The tool will pay for itself if the job has to be done again.

Technical bulletins are becoming more widely available on manufacturers’ websites, so it is always worth checking if there is one for your job, as this could save a lot of time and effort down the line.”

Information on Schaeffler products, fitting instructions, labour times and much more can be found on the REPXPERT garage portal – – and also in the REPXPERT app, or by calling the Schaeffler REPXPERT hotline on (+44) 1432 264264.