So complex has modern engine design become that companies wanting to have their engines remanufactured should first look carefully at their service provider’s equipment and in-house skills profile.

According to Andrew Yorke, operations director of Metric Automotive Engineering, the cost benefit of remanufacturing a ‘new generation’ engine is quickly lost if a vehicle starts to underperform as a result of incorrect parts being fitted, or very fine engineering tolerances not being met.

Yorke warned that there are increasingly critical differences between parts that look the same, and that ignorance of these subtleties will lead to sub-optimal engine performance.

“Rebuilders can give our sector a bad name by not closely complying with engine and component numbers, which reflect a range of small size variations even within one manufacturer’s range of products,” he says. “This is vital because it is no longer possible to identify the differences simply by a visual inspection.”

“The danger for the end-user,” he says, “is that it is very difficult to establish why a remanufactured engine is underperforming once the vehicle is back on the road, and the engine’s power, fuel efficiency and emission standards may be compromised.

Achieving a high standard of remanufacture therefore requires both the right workshop infrastructure and a higher level of engineering skill than in the past, he says. When customers source remanufacturing services, therefore, they should audit the remanufacturer’s equipment to check that it is up to the task of being applied to new generation engines.

“As the most comprehensively equipped diesel engine component remanufacturer in the country, our facilities have kept abreast of key industry trends – including the move towards larger and heavier diesel engines,” he says. “So we now have one of the most comprehensive crankshaft grinding facilities in Africa, which is capable of grinding shafts that are up to 4,7 metres long and weigh up to2 tonnes. This allows us to grind crankshafts from industrial compressors right through to the V16 locomotive diesel engine.”

The workshop also boasts a state-of-the-art, three-axis CNC machines – the only two of their kind in Africa. The machines can do line-boring, surfacing and blue-printing of blocks up to 6 metres in length, and are suitable for dealing with the very large engine blocks found in the heavy equipment sector, as well as in marine and rail.

“Tighter machining and clearance tolerances also call for far higher skill levels among remanufacturing engineers and artisans, as there is simply less room for error,” says Yorke. “Our experience in this business ensures that our highly skilled in-house engineers understand new generation engines, and are familiar with all the engine variants and appropriate components. For instance, we just don’t sell parts unless we know the serial number and the arrangement number.”

This capacity and expertise positions Metric Automotive as a world-class remanufacturing centre, he says, whose quality of workmanship is the equivalent of operators anywhere in the world – while offering its services cost effectively to markets across Africa and abroad.

Metric Automotive Engineering is the most comprehensively equipped diesel engine component remanufacturer in the country.


Users of equipment driven by diesel engines can look forward to many more years of economical operation if they understand that these modern engines are designed for two, three or more ‘new lives’ between overhauls; but proper maintenance goes hand-in-hand with quality remanufacturing to make this possible.

“Beyond their first overhaul at about 15,000 hours, most diesel engines are designed to be overhauled several times,” says Andrew Yorke, operations director of specialist diesel engine component remanufacturer Metric Automotive Engineering. “However, many users will try to cut corners on the maintenance side, especially under the current tough economic conditions – quickly putting pay to this valuable benefit.”

The end result of poor maintenance practices is that machine ownership ends up costing more, and the potential value of a longer working life for the unit is lost.

“Sadly, the situation leads to a sort of self-fulfilling prophecy, where the purchasers of used equipment are even less likely to maintain it properly – arguing that it is not worth the expense,” says Yorke. “They buy used plant because they can’t afford new, but then further undermine its value by wanting to spend less on servicing too.”

The fact is, he says, that many engines do not get the right level of service workmanship or the best quality parts at the latter stages of their lives – so their possible longevity is cut short.

“By viewing the equipment and its engine as a pure cost, the asset value and reliability is not fully realised, and the second and third lives of those engines are severely compromised as a result,” he says.

Several original equipment manufacturers (OEMs) contract Metric Automotive Engineering to remanufacture customers’ engines that are still under a maintenance plan – as a positive way of protecting their warranties.

“From an engineering point of view, we can see the difference between those engines that have been correctly and timeously maintained, and those that have not,” says Yorke. “The condition that these units are in varies dramatically.”

He adds that the component repair costs of a well-maintained engine are also significantly lower, so any savings that an end-user thought they were going to make – by reducing maintenance or by stretching service intervals – is completely nullified by the cost they pay to repair the engine components during the mid-life overhaul.

“Equipment users should also consider the ‘complete picture’ rather than just viewing an engine overhaul in isolation,” he says. “The condition of each component has a knock-on effect on the others, so they need to consider the transmission, the cooling system, the air filtration and other elements.”

If these components are not in good condition, they will in turn compromise the engine; indeed, an overhauled engine could even introduce power levels to the other components that they are no longer in a position to deal with sustainably.

Yorke emphasises that for owners of poorly maintained engines, the extra costs incurred during the remanufacturing process might still be the least of their worries.

“There are plenty of worst case scenarios for an unmaintained engine,” he says. “For instance, lack of maintenance could lead to premature failure, where the equipment has to be withdrawn unexpectedly from service with all the related costs due to project disruption.”

Even worse than that, the customer could experience a catastrophic engine failure, where there are components damaged to the point that they cannot be salvaged or remanufactured.

Among the benefits of quality remanufacturing is the dynamometer testing that follows a complete engine overhaul. While poorly remanufactured engines usually fail within the first 500 hours of life, they are unlikely to endure even an hour on Metric Automotive Engineering’s specialised workshop ‘dyno’ – giving the customer peace of mind that the unit is fit to return to service.

Several original equipment manufacturers (OEMs) contract Metric Automotive Engineering to remanufacture customers’ engines that are still under a maintenance plan .


Leading diesel engine component remanufacturer Metric Automotive Engineering is once again ahead of the curve, installing and commissioning the largest crankshaft polishing machine in Africa.

“This custom engineered, one-of-a-kind machine is capable of accommodating crankshafts with lengths of over six metres,” says Andrew Yorke, operations director at Metric Automotive Engineering. “It represents our philosophy of investing in the latest bespoke and best practice technology, so that we can offer our customers around Africa a world-class standard of service.”

Yorke says that while crankshafts have traditionally been ground and then polished on grinding machines, this is certainly not the ideal solution.

“Polishing debris contaminates the crank grinding machine and this can lead to accelerated wear on critical areas of the machine,” he says. “Moreover, not all crankshafts need to be both ground and polished; some only need polishing, and doing this on a grinding machine is not the best use of this asset.”

Metric Automotive Engineering’s dedicated polishing machine will significantly raise the company’s productivity, enabling even more rapid turnarounds on those crankshafts that require only polishing and not grinding.

“We will also employ this machine to polish camshafts after the re-profiling of the component, or if the journals and lobes only require a polish and not a re-profile,” says Yorke. “Polishing of these components after grinding is vital, as it removes grinding burrs and ensures that the surface finish is ideally matched to the requirements of the bearing materials they run on.”

He emphasises that, in the case of crankshafts and camshafts, there are journals which run on the bearings and lobes which have roller followers carrying high loads. These require the best possible surface finish in order to prevent roller skidding or seizure.

“By polishing these journals and lobes to the correct surface finish, we can return them to OEM specification or better,” he says. “In turn, this leads to improved component performance and longer engine life.”

The company remanufactures heavy diesel engine components for a range of different end-user industries, and has developed a long and impressive track record over almost 50 years. It has generated its extensive capabilities by staying abreast of the latest global developments in diesel engine technology. To ensure the highest standards and expertise, it also maintains close affiliations to the leading diesel engine OEMs.

Repairing and remanufacturing modern diesel engine components to their original OEM specification is an exacting science, says Yorke, and requires long-term development of expert skills and ongoing investment in specialised equipment like this state-of-the-art polishing unit.

Metric Automotive Engineering remanufactures heavy diesel engine components for a range of different end-user industries, and has developed a long and impressive track record over almost 50 years.