ArvinMeritor and Eaton are two giant US corporations which have been in head-on competition for decades. Initially, when Meritor traded under the now-defunct Rockwell name, their rivalry centred primarily on axles for trucks and buses; not only in North America but in many other parts of the world. Both entered into joint ventures with European companies, Rockwell/Meritor with Iveco and later Volvo, and Eaton with MAN.
When it came to transmissions (ie gearboxes), Eaton’s only competition on the US market came from Spicer, part of Dana Corporation. But its SST ten-speed constant-mesh splitter box fell out of favour with drivers. Eaton’s Fuller Roadranger nine- and 13-speed boxes were, and are, of range-change rather than splitter form and although they too are non-synchronised, drivers find them very forgiving. With practice and experience, they can even shift up or down without using the clutch.
After the Spicer SST had quietly faded from the scene, Eaton and Dana in the 1990s undertook what amounted to a product swap. Dana took over Eaton’s drive axle operations, including the big manufacturing operation at Pamplona in Spain, while Eaton acquired the important Spicer clutch business.
The swap left Eaton with a virtual heavy-duty gearbox monopoly in North America, although its patents on the Roadranger were soon to expire.
The swap left Eaton with a virtual heavy-duty gearbox monopoly in North America, although its patents on the Roadranger were soon to expire. That gave Rockwell/Meritor the chance to enter the transmission market for the first time. It put into production a nine-speed range-change box which was a virtual clone of the Roadranger. It had no technical USPs, but it had a price influence, effectively keeping Eaton’s prices in check.
Clearly, with its own product a mere copy of the Roadranger box, Meritor could never hope to become a major force in the US heavy-duty gearbox market. So the corporation looked across the Atlantic to Europe’s largest producer of commercial vehicle transmissions, namely ZF. The German company, unlike its American counterparts, had begun developing syncromesh gearboxes for trucks and buses back in the 1960s.
The pros and cons of the constant-mesh versus syncromesh argument have been well aired, but they boil down to two definitions of easy shifting: with either minimum physical effort or minimum driver skill. Truck drivers in the US and Canada have traditionally prided themselves on their professional acumen in gearshifting, that is their ability to judge engine and road speed so precisely that up- and down-shifts could be made both silently and effortlessly without the aid of syncromesh.
In Europe it was deemed more important for the most inexperienced drivers to be able to change gear rapidly, especially in an emergency situation, even if it called for muscle power from the driver’s arm. Eaton, it should be noted, developed a syncromesh range-change box in the 1990s, especially for the European market. It was taken up by MAN and the small UK-based independent heavy truck makers still around at the time.
Though the ArvinMeritor-ZF joint venture has been moribund since the 2005 verdict, it now seems certain that it will be revitalised
Crucially, that Eaton box incorporated a patented design of synchroniser cone, which was based on the self-servo principle. The effect was to significantly reduce gear lever effort as the rotational speeds of the meshing gears were co-ordinated. That patent is at the heart of a dispute between Eaton and Meritor which has ricocheted to and fro for the last six years.
Meritor wanted to market ZF’s AS-tronic AMT (automated mechanical transmission) - branded Freedomline - in North America in competition with Eaton’s AutoShift AMT. Eaton objected and took its rival to court on the grounds that the ZF-designed box contravened its synchroniser design. There were evidently differences of opinion on the protection of US patents versus European patents. In 2005 the US courts ruled in Eaton’s favour. That left it with effectively a US monopoly, though truck OEMs such as Volvo could offer an in-house AMT.
But last week that decision was overturned, largely on the basis that Eaton’s near monopoly went against US anti-trust laws. Though the ArvinMeritor-ZF joint venture has been moribund since the 2005 verdict, it now seems certain that it will be revitalised, with the US corporation looking to establish plant on home soil to first assemble and later manufacture the ZF product.
The opinions expressed here are those of the author and do not necessarily reflect the positions of Automotive World Ltd.