New transmission technology is set to shake up the construction industry reports Tristan Wiggill.

Volvo Trucks has introduced three innovative features; the F generation i-Shift gearbox, which is now available with crawler gears; tandem axle-lift technology and a new heavy-duty bumper for the long-haul FH model.

The company pointed out a number of small changes made to the gearbox during the launch event at Gerotek in Pretoria recently, which, it says, enhances efficiency and improves shift speeds. The transmission is now also suited to a greater number of applications as a result of clever gearbox software tweaks.

Most importantly though, crawler gears have been added to the company’s standard i-Shift gearbox. The two extra gears make it possible to start a truck from standstill with up to 325 tonnes in total weight loaded. This is unique for series produced heavy trucks. Crawler gears make it possible to drive as slowly as 0.5 km/h and assists heavily loaded trucks drive uphill.

According to Volvo Trucks, the gearbox achieves the same fuel consumption figures as a regular i-Shift and is available on Volvo FH, FM and FMX models. With crawler gears added, total gearbox length increases by 120mm, which brings it to the same length as a normal manual gearbox, while adding 48 kg.

There are two crawler gears: ultra-low and normal. While first gear in a standard i-Shift has a gear ratio of 14.9:1, the normal crawler gear is 19:1 and the ultra-low crawler gear is rated at 32:1. What this means is that when you start a heavy-loaded vehicle in the crawler gears, you are only putting 25% of total energy through the clutch. This means one can do repeat starts, with heavy loads, without burning the clutch.

Lift-off

The tandem axle lift makes it possible to disengage and lift the rear axle when necessary, making a 6×4 a 4×2 or 6×2 combination. This saves up to 4% on fuel costs compared to a vehicle with both axles on the ground and benefits those in heavy transport where the return trip is often empty or partly loaded.

The inter-axle differential on the first axle has been replaced with a dog clutch, thereby allowing the driven axle to be disengaged and lifted, even when driving. This means better traction, especially when driving empty on soft surfaces like gravel.

One will benefit also from reduced tyre wear while enjoying improved manoeuvrability as the turning radius is reduced. With the second drive axle lifted, rolling resistance is reduced and driver comfort improved as noise and vibration are quashed.  The tandem lift system has to be engaged by the driver, although it will drop automatically should the payload reach a certain level. The manufacturer says it is looking at introducing an automatic function for this, but that it is not currently available.

On the long-distance road going Volvo FH, the company has introduced the new heavy-duty front bumper, as per the Volvo FMX. It features a 3mm thick steel plate that is covered in a wear-resistant coating. This adds about 130mm to the FH’s front overhang but, because of its shape and angle, doesn’t compromise the truck’s approach angle.

Operators will be relieved to know the bumper protects the costly headlights from major impacts and, because it is a three-piece design, can be replaced in sections instead of in its entirety should it be damaged.