20 June 1998

POWER UP A NOTCH

Heavier and more powerful versions of the Maxxum MX tractor fill out the Case-IH range for arable tillage operations. But there are newcomers at the workhorse end of the range, too. Peter Hill reports.

THE names the same but the latest Maxxum uses little of the hardware from its predecessor.

As part of the planned development of the second-generation Maxxum, Case is extending the range in both directions. Most significant structural change when the four 100-135hp models were introduced last summer was the switch from side-rail to full chassis support for the engine.

Apart from extending the wheelbase, this layout is better suited to operating heavy front-mounted equipment and relieves the engine of any stress-bearing role. Separating the power unit from the transmission casing also helps isolate the cab from engine-generated noise and vibration.

This layout is repeated for the big newcomers, the 151hp Maxxum MX150 and 166hp MX170, which neatly span the gap between the 135hp Maxxum MX140 and 7210 Magnum Pro which shares the same 170hp rated speed output of the top Maxxum but is both bigger and heavier.

The MX150 and MX170 also share the same looks and overall design as their less powerful brethren, albeit suitably scaled up. The wheelbase is extended by 150mm to improve weight distribution and stability when using heavy mounted implements and, although the transmission is the same in concept, offering four powershift speeds in four ranges to give 16×12 or 32×24 with the optional creep box added, it has bigger gears and shafts to cope with the extra power and torque.

Clutch packs and other key parts are also uprated. The additional power, meanwhile, comes largely from fuelling adjustments and adding an inter-cooler to the turbo system of the 5.9 litre Case-Cummins motor. Maximum power delivery, at 1900rpm, is 161hp and 177hp so both tractors gain power and torque when increasing draft load pulls the engine down from its 2200rpm rated speed.

At the other end of the scale come three C series Maxxum MX tractors. At 84hp, 90hp and 102hp, they represent a higher specification alternative to the Perkins-engined CX tractors of similar output that Case started selling here earlier this year.

Compared with the CX models, the newcomers have a more versatile four-speed thumb switch-operated powershift instead of simpler synchroshift gearboxes, they can lift quite a bit more on the three-point linkage and deploy a larger amount of oil to power ancillary equipment.

MX170 now tops the Case-IH Maxxum MX range. Its inter-cooled turbo engine pumps out 166hp at rated speed, climbing to a maximum of 177hp.