ZF’s aftersales programme in the UK is delivered by a combination of a wholly-owned subsidiary and several service partners. Keeping its customers on the road is key to how it does business with them
ZF Services UK is a wholly-owned subsidiary of the German driveline and technology giant. It recognises that regardless of how good the axles and gearboxes from Friedrichshafen may be, they are nothing without the highest standard of support.
To deliver that, it provides aftersales back-up from a head office in Nottingham and premises in Crick in conjunction with a network of highly-trained service partners.
ZF Services has expanded its senior team since 2017. It recognised that it needed to be closer to its customers, and it believes that such a reset is paying dividends.
Although the partner network would usually be an operator’s first point of contact, ZF Services acts as their ‘mother ship’. It provides training, support and other backup to enable the rapid rectification of problems, or the replacement of units where applicable.
“We are rebuilding relationships with operators, but not to the detriment of those that are already established between them and our partners,” says Service Manager Debbie Fisher. “All of our partners’ technicians are trained to the same standard as our own, but any operator – large or small – can make contact with ZF Services first if they choose to. We are more than happy to act as the conduit between them and a partner.”
Supporting operators
The support aspect of what ZF Services does is key. Besides training its partners’ technicians, it also offers tuition to operators’ engineers, at either Crick, Nottingham or their own premises.
Sessions that involve employees from more than one operator are particularly productive, and when training is held at Nottingham, ZF Services’ relationships with local bus operators mean that it can usually obtain the use of a vehicle to give a more ‘real world’ flavour.
Additionally, ZF Services has taken engineering apprentices from a number of major operators to its workshops and familiarised them with the EcoLife gearbox. In return, the supplier’s own apprentices spend time with an operator.
“That has benefits all round; it helps the apprentices and it also allows us to forge closer relationships with operators,” says Technical Manager Tim Jordan.
Gearbox remanufacture
At Nottingham, one the principal tasks is the remanufacture of coach and bus gearboxes. Among stock awaiting attention, the EcoLife is prominent. So too is the AS-Tronic automated manual transmission (AMT). Older Ecomat models are also supported, and the first overhauled Traxon models are also on the shelf awaiting a call to action.
“We have already stripped and rebuilt Traxons to ensure that our staff are fully trained,” says Debbie. Also available as remanufactured units are the higher input torque EcoLife variants that are used in coaches.
When gearboxes arrive for remanufacture they are first thoroughly inspected. Anything that needs replacing – including the casing if it is damaged – is dealt with, and a comprehensive overhaul is then undertaken that culminates with extensive testing in a dedicated facility.
“We have casings for all models in stock. Among overhauled gearboxes that are ready to go are those with and without angle drives, meaning that we can meet all requirements,” Debbie continues. Meanwhile, parts are dispatched to operators and service partners from Nottingham on a next-day basis, and ZF Services encourages the former to carry out repairs themselves at depot if they have the skillset to do so.
Service partners are able to change gearboxes at customers’ operating centres, typically within a day. In the case of AMTs, the clutch may also be replaced at the same time. All service partners’ staff have been trained in how to do that.
“That’s part of what we’re trying to achieve with a one-stop shop approach,” says Debbie. “The operator calls us, tells us what gearbox the vehicle has, we deliver a replacement unit, and the service partner fits it.
“Then the old gearbox is taken away. Alternatively, the operator can carry out the work itself.”
Axles, too
Remanufactured axles for all manner of vehicles, including Euro 6 models, are held in stock at Nottingham and dispatched on the same basis as gearboxes.
ZF Services has contracts with a number of large bus groups for axle reconditioning, and at the time that routeone visited Nottingham, those for various vehicle types were dressed and awaiting dispatch.
The stockholding will soon extend to the AVE130 electric drive axle, which has hub motors. As an alternative, the CeTrax has a single centrally-mounted motor in a more traditional layout.
The AVE130 gives the potential for a fully low-floor layout, and ZF believe that is where the market will go when electric buses are fully integrated into the UK landscape.
It is suitable for use with battery-electric, hybrid and hydrogen fuel cell drivelines, and while software allows acceleration to be limited, the rate at which road speed is gained remains consistent regardless of gradient or passenger loading. Additionally, the AVE130 has a safety feature that prevents it from generating electricity when the vehicle is being towed with the motors connected.
Stop-start for EcoLife
ZF has developed the EcoLife in recent years with a focus on efficiency. It has also had a close eye on noise emissions, and engine speed is key to that. “How the gears within the transmission are cut and machined also plays a part,” says Tim. “Engaging the torque converter’s lockup clutch as early as possible is important, for both noise emissions and fuel efficiency.”
The torque converter is also key to engine stop-start. That function is now standard on all EcoLifes with maximum input torques of between 1,000 and 1,600Nm, with work centring on ensuring that the converter retains oil pressure for long enough when the engine is off.
“That gives us almost unlimited ‘off time’ and it allows the smooth re-engagement of drive when the engine restarts. There is no limit to the number of stop-start cycles that the gearbox can perform,” he continues.
Although stop-start is perhaps not seen by the industry as a significant fuel saver, ZF’s trials show that in heavily urban drive cycles it can deliver a reduction of up to 10%.
Data illustrates that under these circumstances, per annum a bus may cover 60,000km, undertake 348,000 stop-and-go cycles and spend 1,933 hours at a standstill with the engine running.
As a result, stop-start is designed for buses that are subject to highly-intensive operating cycles. As the commercial speed increases, the benefit of stop-stop becomes less apparent, but it still delivers a slight improvement on those less intensive duties.
New model coming
More information has been revealed about the PowerLine automatic gearbox, which ZF had already suggested would be suited to bus work in lower-torque applications. The eight-speed PowerLine can accept a maximum input torque of 1,400Nm. Although that puts it into the scope of engines that are used in heavyweight buses, the manufacturer plans instead to target it at the lighter sector, which is more price-sensitive.
“The PowerLine has been developed from gearboxes that we already supply to car and van OEMs, and because of that there is a volume benefit,” says OE Account Manager Nigel Marson.
ZF is already engaged with bus manufacturers about the PowerLine, and it expects to have the first on the road in a PCV application towards the end of 2019. As yet there is no data on time between overhaul when compared to the EcoLife, but the PowerLine is significantly lighter than its bigger brother.
“We see a good midibus market for the PowerLine, and also in midicoaches. Because it has eight gears, it can keep engine speeds precisely within the torque band. That benefits fuel economy . The PowerLine will also lend itself to retrofitting to existing vehicles.”
While ZF Services and its partners continue to focus on delivering aftersales support, there will still be much more to come from its parent company in the short- and medium-term. Potential for hybridisation of both the Traxon and the PowerLine is already apparent, and when combined with two variants of axle for zero-emission bus operation, the German giant is clearly looking toward the future.
