UK: US automakers try new diff lock
GKN Driveline has begun production in the United States of a new electronic differential lock for two- and four-wheel-drive vehicles.
The new unit is easier for drivers to use, locks faster and responds better at higher speeds and lower temperatures than pneumatic-based differential locks and competing products the driveline specialist claims. Vehicle owners push a button to handle off-road and other difficult driving conditions and system also automatically disengages at higher speeds.
Referred to as an 'EDL' by GKN Driveline's torque technology group, the new electronically controlled device - especially suitable for the light trucks and off-road vehicles popular in North America - recently went into production at the company's renovated assembly plant in Bowling Green, Ohio.
It will debut during the 2007 model year as standard feature on one unspecified US manufacturer's four-wheel-drive vehicle and be offered as an option on several other models. A second US auto maker will introduce a version on one of its 2008 light trucks.
The new EDL was first produced by GKN Driveline in Japan for use on Nissan's Titan, Frontier and Xterra light trucks currently on sale in the United States. Other automakers in Europe and North America are evaluating systems.
The electronic system eliminates the need for air pumps, mounting brackets and tubing that are subject to damage under severe off-road driving conditions.
If caught in ruts, mud or snow, vehicles equipped with the new EDL can be rocked back and forth without disengaging the locker to shift from forward to reverse. More conventional systems require diff unlocking when moving between forward and reverse, an uncomfortable situation for the driver that also places added stress on a vehicle's rear axle.
With four-pinion-gear design, the electronic 'locker' is lighter and requires less package space than current products which are all features that appeal to development engineers, GKN said. The EDL also is lockable with more than a 200 rpm speed difference between two wheels on the same axle.
GKN claims its new EDL is stronger than most competitive products and operates more smoothly and quietly.
Most differentials use a two-pinion design but, by using a four-pinion design, torque capacity was increased over 50% in the same package size.
The Bowling Green manufacturing plant was included in the company's acquisition in 2005 of Japanese-based automotive supplier Tochigi Fuji Sanyo.