Can you profit from clutch repairs?

Malcolm Short, Schaeffler’s Technical Services Manager, outlines clutch best practice to prevent problems and promote profit.

Some workshops are still avoiding clutch work, preferring instead to send it to a ‘specialist’ that, in reality, has simply learnt the tricks needed to avoid having a car stuck on the ramp overnight when what should have been a five-hour job, goes wrong. By following a few simple precautions, all garages can avoid the pain and problems and potentially start turning a profit from clutch.

Identifying the car

Supplying car parts is becoming increasingly difficult, especially when looking at genuine parts from OE suppliers. With millions of errors on the DVLA system, a vehicle registration look-up may not be as accurate as you would think, so furnishing yourself with some basic vehicle details (preferably directly from the car if you have it) will help the motor factor supply the correct part first time.

Good-to-know problem solving information includes finding the correct VAG engine code; knowing where reverse is located on Vauxhall applications to identify the correct CSC; and knowing if a VW has start/stop is essential in identifying the right DMF.

Follow the (free) fitting instructions!

While you are waiting for the parts and/or the car to arrive, it’s a good time to see if any accurate fitting instructions are available, especially if you are not familiar with the vehicle.

Schaeffler’s REPXPERT workshop portal is a perfect place to start, as clutch fitting instructions are free or charge for members to access, and can be saved, printed and attached to the job card.

Whilst you are looking up the TecRMI vehicle manufacturer instructions using TecDoc in REPXPERT, you will pass the clutch application listings, so take a quick look to see how many components are shown and check if you have ordered all of the parts required.

If your technicians do not have access to an iPhone or Android phone (or mobile device) installed with the free ‘DMF Checkpoint’ app, then you can also find and print the critical tolerance values from REPXPERT, so they can accurately diagnose DMF wear when the gearbox is removed.

Equipment

There is not a great deal of specialised equipment required, but a few essentials can make the job easier; a two-post ramp and a working transmission jack (or two if you work on some larger vehicles such as the L200), preferably with a tilting head for a trauma free gearbox refit.

A universal alignment tool will also help with smooth gearbox installation and prevent any damage to the new clutch.

Whilst it is essential to use a special tool to fit a self-adjusting clutch, Schaeffler’s LuK SAC tool has added value in that it can be used during any clutch installation to help prevent judder, and it also includes lots of special alignment tools to suit the latest BMW applications.

Dual mass flywheels can be checked for wear prior to gearbox removal by using a LuK DMF tool, in conjunction with the DMF CheckPoint app

Dual mass flywheels can be checked for wear prior to gearbox removal by using a LuK DMF tool in conjunction with the DMF CheckPoint app. If the DMF does need replacing then the app also tells you if new bolts are required and what torque values to use.

Correct parts

When the parts have arrived and you have removed the gearbox, it’s always worth doing some basic comparisons:

Spline count – sliding the drive plate back and forth to distribute a small amount of grease is a good check that the splines are correct (not forgetting to wipe off any excess grease afterwards).

Drive plate orientation – “Getriebe Seite” is German for “Gearbox Side”, “Schwungrad” is “Flywheel”, and if you see something else or even nothing, contact the free REPXPERT technical hotline – the problems caused by fitting a drive plate the wrong way round are easily avoidable!

Dual Mass Flywheels (DMF) – It is always worth checking the reluctor ring on the back of a DMF, even if it’s from a different manufacturer it should still have the same number of teeth and they should be undamaged. OE suppliers such as Schaeffler will replace transit damaged goods as long as it has been spotted before fitment.

Concentric Slave Cylinders (CSC) – A modern plastic CSC can obviously look different, but it should have the same number of fixings and the pipe position should be similar. It may sound simple, but always read the instruction sheet inside a CSC box! It may contain critical information, such as how to find and discard a redundant pipe seal (on Vauxhall applications), and some Ford instructions explain that the O-ring should be replaced by sealant (and not too much!).

Dual mass flywheels can be checked for wear prior to gearbox removal by using a LuK DMF tool, in conjunction with the DMF CheckPoint app

Check the rest – Worn or seized cross shaft bushes need to be rectified; bent or damaged forks need to be replaced; always replace the ball pivot on BMW applications and check the others; repair leaking gearbox seals and, finally, reset or replace all self-adjusting cables.

Final assembly

Never grease plastic release bearings. On most pull type clutches you fit the release bearing to the gearbox and locate it to the clutch cover after fitting the gearbox. Be careful when inserting the gearbox, swinging up and down on the back of a gearbox to fit it to a poorly aligned clutch will probably cause judder and damage.

If in doubt about any repair, call the REPXPERT hotline on 0872 737 0037 for help. A two-minute conversation could save you hours.

LuK’s SAC tool has added value in that it can be used during any clutch installation to help prevent judder

Training Review: Going Dutch

The partnership between JLM Lubricants of the Netherlands and the DPF Doctor in Northumberland has given birth to the JLM Academy. Rob Marshall gives and overview of the main technical tips from the inaugural training course.

While we should all be a little suspicious of celebrity endorsement, certain techs within the aftermarket have earned their fame, by imparting their expertise to raise standards within the trade. A rising star is Darren Darling. You may have seen his presentation at Automechanika Birmingham earlier this year and, if you have not, it is possible that you have become conscious of his DPF expertise, including his recent elevation to Dutch JLM Lubricants’ brand ambassador. So, has this cheerful Geordie (albeit born in Scotland) sold out? 

“Not at all”, he argues, and explains, 

“I was aware that the modification trade was unsustainable, so my own business had to evolve into another speciality. As many garages tended to have no idea about repairing the growing DPF blockages, I experimented with a number of products and techniques. Since I found that nothing could touch JLM’s products, this kick-started a working relationship with the manufacturer.” 

Darren confirms that his ambassadorial role is also unpaid and, while he receives an annual fee from the vetted garages that have joined the DPF Doctor network, he emphasises that members have no obligation to use JLM products. He explains, “Even so, we prefer that JLM products are used, because we know how and why they work. However, using an inappropriate DPF cleaning product for the presented fault, can not only be harmful but also dangerous, which is why basic training had become necessary for both technicians and suppliers. 

THE JLM ACADEMY LAUNCHES 

The British market is being seen globally as a pioneer in DPF repairs, which was made clear by the JLM Academy’s first training course being supported by not only UK technicians but also the Australian JLM wholesaler, who had flown-in specially for the event and joined Kalimex, the UK distributor. Held on the 10th and 11th September, the two days-long event cost £600 per delegate and it was especially reassuring that JLM Lubricants BV’s Founder and MD, Gilbert Groot, with Ruud Post (Sales Manager) flew over specifically from the Netherlands. 

GO SLOW 

Importantly, the course is not a JLM hard-sell lecture but it presents a logical process that technicians can follow, when confronted with a DPF-blockage. Darren underscores that workshops must price accordingly to allow for the time necessary to assess the vehicle properly. This is not to ‘rip-off’ the customer but to factor that DPF blocking is a symptom of another issue that must also be rectified. Garages that quote and carry-out a rushed half-hour DPF clean immediately are likely to see the car again very shortly, as Darren proved, by a severely split turbo boost pipe on the V50 blocking its brand- new OEM DPF after only 12 miles of open-road driving. 

JLM’s latest intake cleaner was demonstrated. This is another two-step process that is gentle on the engine. Mr
Darling explains that the chemicals soften the oily/carbon mix in the intake that is dislodged during driving

As an engine and its associated components are stressed severely under high exhaust back pressure conditions, detail was provided about why the engine should be run for as little time as possible and under the lightest possible load. A high RPM ‘thrash’, therefore, is likely to be harmful. Basic checks were also detailed, explaining how garages can structure the task and giving solutions to the customer that solve the symptom (unblocking the DPF), effect a cure (diagnosing and resolving the underlying fault) and offer an aftercare service (included as an oil flush/change/filter replacement and additive advice). This is not to overcharge the motorist but it allows the workshop not to operate at a loss, while offering the customer optimum value and minimising the risk of complaints. 

It was also explained when DPF issues tend to be caused by another component, how ash deposits are seldom the reason for blockages and why fault codes should not be reset until a degree of further investigation and live data readings are considered and verified, before being trusted. 

CHEMICAL WARFARE – KNOWING THE PRODUCT 

As iron-cerium based chemicals are available freely for motorists to add to the fuel tank themselves, to assist with raising DPF temperatures to facilitate regeneration, quizzing the customer about whether or not any such products have been added beforehand must be part of the initial information- gathering exercise. DIY overdosing is common and garages could make things worse easily, by adding even more iron- cerium product. The result can be either a melted DPF core, or a serious fire, due to DPF thermal runaway that the ECU cannot control. 

Technicians were taught how to use their judgements, when selecting the most appropriate chemical. Iron-cerium based additives, such as JLM’s DPF Regen Plus, are still useful, if used in the correct concentrations and conditions, to reduce soot build-up in the case of low mileage/urban driving conditions. A combined DPF and injector cleaner (such as JLM’s Catalytic Exhaust Cleaner) can be used as an aftersales product, as preventative maintenance, too, but also acts as an injector cleaner and cetane booster. Yet, more expensive alternative products (such as JLM’s DPF Particulate Filter Cleaner) contain platinum-cerium catalysts that cleanse the filter without causing temperature spikes and should be employed when a filter is moderately blocked with soot. 

For severe blockages, where the cleaning solution has to be injected directly into the DPF via the pressure differential sensors’ flexible pipes, the V50 was used to demonstrate the two stage process of JLM’s DPF Clean & Flush. The session included critical advice to prevent the solution from being forced through the EGR circuit, on severely-blocked filters, and into the intake, which risks hydraulicking the engine. 

The course provided a fascinating introduction for garages to tackle DPF work confidently, while maximising profitability, customer satisfaction and value. It also succeeded by providing JLM wholesalers with sufficient technical knowledge to support garages that may not have access to the detailed level of advice that is available to the DPF Doctor network. 

For course information and booking, please contact Lenny Beers at lbeers@jlmlubricants.com

 

Advice to promote successful suspension repairs

Multi-link suspensions have largely replaced conventional wishbone suspensions, increasing driving dynamics and comfort. The modern design, explains TRW, features one or both wishbones broken down into multiple components, so that significantly more moving parts are installed.

The distance between wheel centre and steering axle – the so-called disturbing force lever arm – is relatively short. This allows disturbing forces (propulsive, braking and lateral guiding forces) to be kept away from the steering as much as possible. However, the joints move closer to the brake, which automatically exposes them to higher temperatures, resulting in significantly higher demands on the installed rubber sleeves and plastic bearing shells, as well as for the grease used.

More moving parts also means more joints connecting the parts, this results in a higher sum of ‘moments’, which are divided into breakaway torque and running torque. Breakaway torque results from the force required for setting the ball pin into motion from its resting position. The running moment results from the force required for rotating the ball pin or moving it back and forth in the joint.

Development engineers try to keep these moments as small as possible as this ensures, for example, that after cornering the front axle returns to the centre position independently and smoothly and that the suspension responds more sensitively. Today, so-called low-friction ball joints are used that have a substantially lower friction moment than previous types.

While a smoothly moving ball pin used to indicate increased wear of the ball joint, this is no longer the case. Modern ball joints have distinctly lower breakaway torques and running torques.

DEVELOPMENT AND DESIGN OF A MULTI-LINK SUSPENSION

The product specifications defined for a multi-link suspension are determined during extensive test procedures on a test bench as well as in the vehicle. The associated moments (running torque and breakaway torque) as well as the damping properties of a joint always have to be considered within the overall system.

The influencing factors for steering systems, suspension, springs, brakes and tyres are extremely important for the functioning of the overall vehicle and for vehicle safety. Altering individual components and specifications is only permitted with consideration of the overall concept and always requires approval from the vehicle manufacturer.

Screen Shot 2017-11-29 at 18.41.28MAINTENANCE AND REPAIR

Mechanics should observe several points when replacing individual components.

When replacing a ball joint, the eye and the rubber contact surface in which the joint is installed have to be cleaned and any rust removed. The contact surface must be free from rust or the rubber sleeve will rub against the rough surface and leak. Dirt and moisture can enter the joint, which leads to premature joint failure.

During installation, it has to be ensured that the corrosion protection layer of the circlips is not damaged, as rust causes them to lose their spring force, allowing moisture ingress into the joint, significantly affecting service life.

Never tighten the ball joint with an impact wrench. There is a risk the ball pin could start to rotate so fast that the plastic bearing shell becomes deformed by the frictional heat, leading to play in the system. Furthermore, the tightening torque can be exceeded, causing the ball pin to move too high into the eye of the stub axle. This means the rubber sleeve can no longer fulfil its sealing function, allowing dirt and moisture to enter into the ball joint.

The rubber bearing on a control arm may only be tightened when compressed and without load to avoid twisting and therefore applying pre-tension to the bearing.

The installation errors described here can lead to premature wear or even failure of the replaced part. Garages should always carry out a wheel alignment after replacing suspension parts, even if only axle components were released. If these simple rules are followed, all suspension repair work can be carried out successfully.