JCB has been building wheeled loaders since it took over Chaseside in the late 1960s. And, like all competitive products, the JCB range has come a long way since then.
Yet even members of the companys management would admit that during the 1980s JCBs wheeled loaders fell a bit behind in the technology race, as electronics made their way into mainstream machinery. And the Staffordshire company took a long time to react to customer demand for rear-end mounted cabs and Z-bar linkages.
But the result of this delay looks impressive, as Dan Gilkes discovers.
LAST year JCB replaced its ageing 425 and 435 loaders with the new 426/436. They feature rear-end cabs, improved transmissions, higher output engines, hydraulic braking and a choice of Z-bar and four-ram arms. For the first time in a number of years, the JCB wheeled loader line-up looks like a very serious competitor for the heavy rock digging market leaders.
But looks are one thing, and performance is something else. We took the biggest machine in the range (so far) and put it to work in a Staffordshire sand and gravel quarry to see if JCB has really come up with the goods.
The 436ZX in detail
The first thing to hit you about the 436ZX is, of course, its layout. The now conventional articulating frame has the cab mounted on the rear half, above and in front of the engine. The front half of the chassis concentrates its strength around the mounting tower for the single- piece loader arms and rams.
The machine has a pleasing design with a good low centre of gravity and a relatively low sloping bonnet line to the rear. The cab is gently curved at the front with a glass-to-glass join on the windows for maximum visibility. And the ROPS/FOPS structure at the rear is well integrated.
A six-cylinder Perkins turbo-charged engine provides 164 PS of power (6 per cent up on the old 435) and 567 Nm of torque. A ZF powershift transmission provides four forward and three reverse speeds to all four wheels. Electrical operation of the gear change provides smooth modulation between gears and the machine has a top forward speed of 38 kph. A fully automatic box is available as an option, though I would not have thought it necessary for general use.
The loader uses two variable displacement piston pumps to provide hydraulic power, and during the test it proved well up to the job of filling the bucket and offering a fast turnaround.
Engine noise levels are just 75 and 106 dB(A) inside and out, which is respectable for this size of machine. So much work has gone into keeping the engines quiet in so many of the loaders now on the market that quite often other parts of the machine then become more audible.
Driving the ZX proved that the engine is both powerful and quiet, and the transmission is fast, easy to use and equally quiet. This lack of noise exposed the steering as the next point of call for the engineers, as it was unusually audible, though that may have been just on our test machine.
At the front end, the ZX loader arms look as if JCB has been in the Z- bar arena for years. Clean lines and strong, single-piece arms have plenty of breakout force for the toughest of jobs. However, we did feel that, though the 436ZX has plenty of hydraulic power to dig into the pile, and the ability to carry the spoil around the site, a 5-tonne bucket load proved almost more than enough in terms of stability.
Down at ground level, the heavy-duty axles perform well. Limited slip differentials are optional in both axles, and on some sites they will no doubt be seen as essentials. But traction is good and reasonable rear axle oscillation keeps the wheels on the ground in all but the roughest terrain.
A ride suspension system is not available yet, but watch this space.
To bring it to a halt, JCB has followed the current trend with oil-immersed, dual-circuit multiple disc brakes which have plenty of stopping power and cut down on regular maintenance.
At the controls
Inside the cab, wheeled loader managing director John Appleby and his team have done JCB proud. The layout is clean and uncluttered, with the main console on the right of the cab in front of the attachment controls. It looks very modern yet retains a JCB family feel which operators should find easy to use.
A fully adjustable suspension seat is standard along with a tilting steering column. Transmission kick-down is built into the head of the hydraulic arm lever as well as the gear change, so you can drop the machine into first as it hits the face without taking your hand off the controls.
The 436ZX has nice chunky controls that you can really get hold of, and which feel as if they can stand the test of time. The cab is also easy to keep clean. Thick rubber mats are fitted throughout, extending up the sides and channelling dirt and water to the door.
It might not seem important at this time of the year but cast your mind back to last summer and you will welcome the air-conditioning system that provides filtered cool air to the operator. And there is plenty of space for storing personal belongings.
Gull-wing doors at the rear expose the engine on both sides. Accessibility to service points is excellent. There is no lying on the wheels to get at things, it can all be reached from the ground.
At the back the radiator cover hinges up and the oil-cooler can be swung out to clean it on both sides.
And at the front, heavy- duty polyurethane covers protect the hydraulic valve block from bucket overspill.
All of the pivot pins are specially treated and have lip seals to prevent the ingress of abrasive dirt. Greasing at the front end is just once every 100 hours.
As with all Construction News plant tests, we put the machine onto site and attempted to create realistic operating conditions (see opposite page).
The manufacturer supplies an operator who is familiar with the machine and is briefed on the operation. A fuel-flow meter was fitted to the machine to give accurate consumption figures during each test.
Production data is compiled by independent consultant Robert Brown of RB Research, and each hour of operation is calculated to 50 minutes to allow for spotting of trucks and cleaning of the working area.
JCBs wheeled loader division has put a lot of time and work into the 426/436 range. Its also invested 4 million in improving the production line over the past year. And it looks like money well spent.
The 436ZX is well built and well equipped. It has plenty of power for its size and manages to put that power to good use, both in traction and hydraulic output. The market seems to have taken to the machines too. In 1995, JCBs UK wheeled-loader sales of the 436 size rose by almost 75 per cent.
The 436ZX appears to be a hit, and, most importantly for JCB, a hit in a very competitive sector of the market. If rumours are to be believed, JCB is going to build a bigger wheeled loader, to compete in the toughest part of the sector. If it is as good as the 436ZX, it should go into production now.