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The Offi cial Magazine of the

ISSN 1174-7935

A changefor the better

big test

TD97

31

June 2007

After all, let’s face it – manufacturers are not in the habit of pouring millions of dollars into the development of a new or updated model, only to take backward steps in terms of performance or operator friendliness.

But once in a while we do come across a new

model where the report card has to be marked: “Can do a whole lot better.” That was definitely the case with the Isuzu EXY530, operated by Ashburton’s Wilson Bulk Transport, that we tested during 2005. The truck was fitted with Isuzu’s brand-new and self-developed 16-speed automated manual

BIG TEST

A change for the better

Story – Brian CowanPhotos – Mark Barber

USUALLY, on our monthly New Zealand Truck & Driver tests, we don’t find too much that’s majorly wrong with the trucks under scrutiny.

The Isuzu heads out of a farm inland from Te Puke with a load of pulp logs

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transmission, which at the time it called Smoother-G.

Sadly, despite the name, it wasn’t smooth sailing for the gearbox: It proved to be very slow on shifting – so much so that in auto it was incapable of handling the climb over Evans Pass from Sumner to Lyttelton.

The leisurely nature of the shifts meant that all forward momentum was swallowed up by the hill. And, with the box in the manual setting, the driver had to ensure that he dropped down more ratios than would otherwise be needed for the climb, to compensate for the slowness of the shifting.

Even on the flat the system became all tangle-footed when the truck slowed to near walking pace (say, at a give-way sign or approaching a roundabout) and the driver wanted to move off again: It couldn’t seem to make up its mind what gear to pick and on a couple of occasions, driving through Christchurch, it actually locked in one of the high ratios, calling for the truck to be completely stopped before the start-off gear could be picked up again.

Consequently, we've been really keen to evaluate the latest version of Isuzu’s self-shifter. The system – now called MJX16-AMT – is, says Isuzu NZ, “much improved.”

And much-improved is indeed what we can now report – the company obviously listened to the comments on its first attempt and, for the most part, has addressed them very well…to the point where the gearbox has now significantly bridged the gap to the best from Europe.

Host truck for our revisit of the system is an 8x4 CYH530 running as a truck and trailer logging combination and operated out of Rotorua by Williams & Wilshier. When we meet up with the rig at Opotiki early on a midweek morning it’s on its way to the Port of Tauranga loaded with export 3.7s – and there’s a familiar face in the cab: Peter Johnston was the driver of the W&W Volvo FH12 which we covered in the September, 2003 issue in a feature on the introduction of EBS braking for trailers.

Now he’s settling into his first fulltime Japanese truck after years of European and American iron – plus his first automated manual. So, is it proving to be a rude culture shock?

Says Peter: “I was a bit apprehensive coming in. The sign on the side said ‘530’ but I’d had brief experiences with other Japanese engines and found them short on promise, so I was prepared to be disappointed – but it’s not too bad at all. In fact, I’m

impressed with how it performs.”So what about his entry into the

word of self-shifters? Again, the response is very positive, though like most experienced drivers, Peter chooses when to leave the gearbox to its own devices and when to pick the manual setting.

“If you’re slowing down for a turn or roundabout in town the gearbox can tend to want to shift up into a higher gear than is needed to pull away. I find if you keep your foot gently on the accelerator it holds it in a lower ratio, ready to move off. However, it’s often just as easy to either pop it into manual or use the manual override to knock it down a gear or two when required.”

From an ergonomic point of view, the Isuzu is set up ideally for this sort of driving. Cycling between full-auto or full-manual is accomplished by pushing a button set on top of the stubby little shift lever – up for manual, down for auto. In manual the lever is pushed forward for one gear up, back for one down. The action can also be used in auto setting, momentarily overriding the controller but then reverting to self-shifting after a few seconds.

As Peter explains: “That’s for the situations where you’ve got it in auto

As the logs go on the truck and its Patchell trailer, Peter Johnston keeps an eye on the scale readout situated on the cab protector frame

but you can see a change is needed. To be honest, when I’m loaded I keep it in manual most of the time, because it’s quite sensitive to the accelerator. When the road’s rolling up and down, even gently, there’s a tendency to press a little harder on the pedal when it rises, which means the system will chop back a gear or two – then as soon as you ease off as the road drops, it shifts up again. The more juice you give it the more it’s going to go up and down. One way to avoid this is to keep

a steady foot on the accelerator, but I find it’s easier to shift the box into manual mode.

“Empty, it’s not such an issue, because it’s easier to keep a steady right foot and of course you don’t get the same drop in speed on the little rises in the road.”

Naturally, at the start of a steep climb the driver is best able to judge what’s needed in terms of choosing the correct gear, but Peter finds the significantly improved speed of the

Isuzu gearshifting mechanism is capable of playing catchup very well: “Even if you have got yourself into trouble and the revs have dropped down to around 1100rpm you can pick three or four gears quickly and it will change in time enough to still pull away.”

In this respect the skip-shift control is very handy, offering as it does two gears with every movement of the lever or command from the control unit, though Peter cautions about

Above: Well-organised dash puts all controls within easy reach, instrument panel offers clear, simple gauges. Minor storage is well thought out – note flip-forward top to centre console box

Left: Stubby shift lever offers sequential gearchanging, has auto/manual mode button on top

Below: Isuzu’s biggest-power engine is still not a giant in terms of outright power, but it is starting to challenge the front runners

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remembering that it’s switched on: “You have to be a bit careful of having the skip-shift button in when you’re changing manually, because if you forget and go quickly for a couple of gears it will try to give you four!”

Ergonomically, the skip-shift control’s position is still dodgy, because it remains on the far right-hand end of the dash. A more useful location would be on the shifting console beside the gear lever.

Peter says he’d also like a facility to hold a gear in auto: “The thing that scares me in auto is that it might get away from me on a downhill by shifting up when I don’t want it to. It’s a pity they don’t have a Hold button like some cars do that can just lock it into a particular gear.”

He also finds sometimes that if the controller feels the speed is a little high for a particular ratio it will not shift into it at the beginning of a downhill, even though it would happily go through without over-revving in a full

manual box: “Say I’m looking for two gears and it only gives me one, what I do then is just tap the service brakes to pull a little speed out of it, then it will go through.”

Unlike the first example of Isuzu’s automated manual, which still used a clutch pedal to start and stop, the latest version handles everything itself. Yet it still carries a clutch pedal, for those times (like easing into a tight loading bay) when the electronic system is not quite as delicate on the slippage as an experienced human foot. Pete Johnston admits to having used the pedal only once – “and that was because I forgot for a minute and went back to my manual instincts! I don’t bother using it for manoeuvring. Even in the bush, on tight skid-sites, I just let it do its stuff – it hasn’t been worried yet.”

As he says, the swap to the new gearbox has meant a whole rethink of the way he drives: “Some guys might think you can just jump in and treat

them the same as a Roadranger, but it takes a bit of adjustment.

The layout of the shift lever and its gate is simplicity itself, with its push forward or pull back shifting – the lever returning to the centre each time. Shifting it to the left, then pushing down and forward against a detente, calls up reverse.

One of the major hassles we discovered with the first version – the system’s confusion in dropping into the correct takeoff gear when the truck slowed to a walking pace – has been brilliantly sorted out. The original system was foxed when the truck was still moving slowly.

To overcome this all that’s needed is to quickly shift the lever left to the neutral position (on the way to reverse), then back to Drive and the controller will instantly drop into the driver-chosen starting gear. This, in turn, is easily reset (for example, after dropping a load and preparing for some empty running) by keeping the

brake on with the truck stationary and using the lever to choose the desired ratio. Naturally, whenever the unit comes to a full stop the same preset gear will automatically be chosen.

Pete demonstrates the improvement as we slow for the Pekatahi Bridge over the Whakatane River near Taneatua. Down to a walking pace, a flick of the lever…and in seconds we’re moving away smoothly.

At the Waimana Hill, which we approach at about 90km/h, Peter picks two gears quickly and the unit crests the rise barely breathing at 65, after dropping briefly to 50 mid-slope. Even allowing for the speed of the skip-shift, you can still detect the gearbox sequencing down between ratios – it doesn’t jump directly to the new gear.

Peter explains that he tries to keep the engine spinning in its happiest band, from 1500-1600rpm: “When it drops to below 1400 I just grab a couple and that brings it back nicely on the boil.”

Though the 6WG1 engine is Isuzu’s

torquiest yet, with a broad power band, it still doesn’t have the low-revs lugging power of comparable-capacity American engines and is happier being spun in the 1500-1700rpm band. However, its combination of high-pressure commonrail injection and cooled EGR put it right up there in terms of meeting Euro 4 emissions standards now and lining itself up for the standards to come.

“I don’t have any problems with the power this produces and its ability to handle heavy loads,” says Peter Johnston, “though it still wouldn’t outdrag a C-15 or a Signature. But give the Japanese a few years and they’ll be right up there.

“The big thing about this model is that now that Isuzu has this high-power engine and automated manual up and running so well it will force Mitsi and Hino to step up to the mark, because they won’t want to be left behind.”

Isuzu is rightly proud of its GIGA-TARD permanent magnet driveshaft retarder – together with the exhaust brake it’s capable of producing up

to 500hp of holding power. However, Peter isn’t easily impressed – he’s experienced the mighty retardation of European hydraulic systems, which he reckons have left him spoilt for pretty well anything else: “I’m not knocking it – it does a good job – but compared with the likes of a couple of ones I’ve driven it’s a distant third.”

He also points out that the whole rig is new – truck AND trailer – so everything is pretty tight at the moment. That makes him more than pleased with the 1.78km/litre he’s achieving after just four weeks and 14,000 kilometres: “I wouldn’t be surprised if by the end of the year it reaches better than 2.0km/litre.”

Since he’s had the truck he’s been mainly working along the coast at Houpoto (near the Motu River mouth), carting out of a Hancocks block that has been sold to CHH. Export makes up a high proportion of the loads – for example the one he’s now taking to the Mount. There are local destinations as well, however: P-grade logs go to Carters ply at Kinleith and saw logs for domestic and export markets go to the

Right: By the standards of American and Euro engines, the Isuzu six seems to be festooned with exterior plumbing, but layout is orderly and maintenance access good

Both below: Electro-hydraulic cab tilt works quickly and strongly; minor servicing points are easy to reach

A secondopinion

WHEN a truck has changed as dramatically as the automated Isuzu, a second opinion is always

handy. To get this we seek out John Pederson, who drives a 6x4 Isuzu 530 semi-trailer unit for PGF Transport of Benneydale.

The truck runs containers across the Kaimais to Port Tauranga, with loads up to 39 tonnes GCM.

Like Peter Johnston, John admits to keeping the gearbox in manual mode most of the time: “I find when it’s starting to climb a hill, it stays in the higher gear for just a little too long, then it drops suddenly through two gears. It’s often better to keep it in manual and take the gears singly.”

He appreciates the skip-shift function, though, finding it allows him to do a quick drop from 11th to 9th to handle the sudden steepening of the slope near the top of the run over the Kaimais: “The setup is very good and the shifting mechanism works well – it’s just that I find it easier to keep it in manual.”

He is especially impressed with the new starting-gear protocol: “It’s really good to know that whatever you choose, that’s the gear it’s going to pick when taking off. And because I’m running empty a proportion of the time, the fact that you can quickly and easily dial in a new start-gear after you’ve dropped the load is really useful.” T&D

A secondopinion

PGF Transport’s automated Isuzu runs back and forth over the Kaimais from the Waikato

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Tachikawa Forest Products sawmill in Rotorua – generally delivered on the way home, at the end of the day.

On a typical day, Peter will travel from Rotorua to Houpoto and cart to the Mount or to the Kawerau sawmill. He also carts out of Rayonier woodlots inland from Te Puke – and a trip from that area will be his next assignment today.

He came out of the FH12 500 into the Isuzu and his mount before that was a 520 Argosy: “There’s no truck as comfortable or quiet as the Volvo, so the switch to the Isuzu was a bit of a shock for a start – you’ve got a big six-rod suspension at the back, so naturally it responds to the road a little more and gives you the occasional kick. On the other hand, go into a corner and this one really bites nicely. You haven’t got the ‘KZ7 lean’ of the Volvo’s soft cab suspension, so it’s easy to place the truck in a bend.”

Peter points out a couple of ergonomic aspects of the Isuzu cab though that he finds less than ideal. One of them is the location of the trailer brake control – set level with his left elbow and calling for quite an awkward pull back of the arm to engage: “Particularly on a steep block, when you’re manoeuvring and backing up and have to pull the brake on when you’re on full steering lock, it becomes very awkward.”

But his fiercest criticism is for the exterior mirrors. Now, on our original test of the Isuzu automated

transmission model – on a tractor unit pulling a tri-axle skeletal semi, from Ashburton to Christchurch – the mirrors didn’t present themselves as much of a problem.

But Peter Johnston points out that in the truck and trailer logging application, the fact they’re designed for a Japanese environment is disappointingly obvious. They are, he says, set so far forward that the left-hand ones are best viewed by the driver leaning forward and looking in front of the A-pillar and around the RUC stickers. Even though they’re power-adjusted, Peter says, they still can’t be brought into any angle that gives a proper view of the trailer from the normal seated position.

Both the main and subsidiary mirrors are parabolic as well, complicating the issue further, while the little front-view mirror that projects above the whole setup is a natural to snag on overhanging branches, he adds.

The mirrors are clever: At the flip of a switch the whole left-hand assembly will swing forward so that it doesn’t project from the side of the cab. Very handy in a Tokyo alleyway…but not a great deal of use when you’re backing into a NZ forest skid site before dawn with the rain pelting down.

Peter also finds that the steering wheel – though adjustable for both swing and telescopically – has limited telescopic range: “If you’re a big guy, it will be too close to your knees. You

can swing it away, but that makes it a long reach for the arms.” Limited fore-and-aft movement of the seat – constrained by the bunk in the semi-sleeper cab – compounds the issue, he finds.

Though minor storage in the cab isn’t bad, Peter mourns the lack of under-bunk lockers, accessible from the outside, in which the likes of rain gear, torches and tools can be stowed.

On the way through to Tauranga we have a driver swap and NZ Truck & Driver tester Trevor Woolston gets behind the wheel. As we climb away from the coast at Otamarakau the new gearbox demonstrates its improved shift action with a quick shuffle back to 13th under manual control. Coming into Te Puke, Trevor leaves it in auto plus skip-shift and it doubles swiftly down to 12th to take the short slope into the town.

There’s a long (near hour and a half) wait at the log wharf while the truck is unloaded. Peter says this isn’t unusual for the busy facility.

Rotorua-based Johnston is a 15-year veteran with Williams & Wilshier and has been driving “nearly forever” (or around 30 years), beginning with International F1800 loggers towing two-axle trailers. Previously he’d been a lineman with the local power board, but had always had a hankering to drive big trucks and jumped at the opportunity when it came up. Logs weren’t the only cargo in his first

decade or so in the job – stock and bulk work also figured at different times. His start with W&W came with intermittent fill-in work on the weekends, which morphed into an offer of a permanent job.

Of the trucks he’s driven with the company, he fondly remembers the first, a Cummins-engined White Road Boss, “a great old truck,” he says. His first new mount, a 500 Foden, is another that carries good memories. With the Foden, he spent some time working on the East Cape, carting export logs from Tolaga Bay to Gisborne during the week, with home loads of pulp logs or peelers every Friday.

A fuel fill at the Mount after leaving the log wharf presents a chance to check out the truck’s specifications, which include central tyre

Right and below right: Logging has played a big part in Peter Johnston’s long driving career. The Isuzu is his first auto and first Japanese truck driven fulltime. Initially apprehensive about both, he’s now a convert

Below: Magnetic retarder isn’t quite up with Jakes and hydraulic systems, but does a solid job

Unloading at busy Port of Tauranga log wharf can mean a longish wait in line. Isuzu’s poor left-side mirror setup is clearly obvious in this shot

Heading along the Bay of Plenty coast. The combination of truck and trailer steers accurately and most times rides comfortably, though rough roads provoke a bit of a reaction from truck’s steel springs

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inflation, steel suspension, alloy wheels fitted with Dunlop tyres and a single 400-litre fuel tank: “It could do with another 100 litres,” says Peter. “That would allow me to get from Kinleith and do a double round trip to home.”

The Isuzu features an electric/hydraulic cab tilt system, plus easy access to the oil filler, dipstick and other fluids under the front grille. The engine is a typical Isuzu, in having a great mass of fuel and air lines around the block.

Completing the combination is a brand new four-axle Patchell trailer, sitting on ROR axles and air suspension, Alcoa alloys and fitted with SI Lodec scales. The truck is fitted with ABS, but the trailer doesn’t have EBS. The scale readout unit mounted in the side of the cab protector also carries the central control that brings the air suspension units on the trailer up to pressure for accurate reading when the unit is being loaded. The truck tare weight is 11,020kg and the trailer 5340kg.

Returning empty from the Mount with Peter once again at the wheel, we head back along the coast to Te Puke, turning inland on the No. 3 Road and heading a few kilometres inland to a big farm woodlot where a load a pulp logs for Kinleith awaits.

Turning off the main road, he demonstrates the combination of automatic and manual shifting he employs when running empty: “As I approach the corner I leave it in auto, but manually override it, skip-shifting down to the gear I need for the bend that in auto it might be reluctant to pick. Then, as I pull away it’s still in auto and picks its own upshifts.”

The home run to Rotorua sees Trevor Woolston back at the wheel and the GCM close to the maximum. Coming through the comparatively tight gate out of the farm lot and a few kilometres later turning onto the main road, the mirrors prove themselves to be seriously lacking.

On the rolling country just out of Paengaroa on the Te Puke to Rotorua road, the sensitivity of the gearbox to accelerator position – shifting up at the slightest easing on the pedal, then dropping down again when the pressure comes back – is quite evident. Trevor agrees with Peter that this is a situation where leaving it in manual would help, though the responsiveness of the shift controller – so lacking in the earlier example – is impressive.

In fact, there’s a great deal about the latest big Isuzu that is impressive. In many areas, it proves that the Euros and Americans cannot afford to stand still, because as soon as they do, models like this will be on their heels. T&D

WELL, what an improvement! Isuzu seemed to get it all wrong

first time up with its automated manual box, but now it’s delivering the goods. It still doesn’t have all of the answers all of the time – no automated transmission yet does – but it does cover the bases you’d expect it to cover.

As for the rest of the truck, it’s pretty much the GIGA that’s been part of making Isuzu the market leader here – not perfect in many ways, but a good, solid performer that shows that Japan is bridging the gap with its heavy trucks.

The horsepower curve is still a fairly typical Japanese one, in that the engine feels happier spinning above 1400rpm. However, it has a nice spread of effort down to about 1200rpm as well.

The service brakes are really strong and while the two-stage retarder system (exhaust brake only, then that plus the permanent-magnet driveline unit) might not be the strongest in the world, it does the job required.

There’s plenty of space in the footwell and though the seat is limited in its back and forward movement it is comfortable and the overall driving position is as well.

Ride is generally good, though as we approach Edgecumbe on SH2, a particularly bumpy section promotes a certain amount of pitching from the drive-axle suspension. Steering feel and the balance of the combination on the

road is good. You don’t get any bump steer and the truck stays predictably on line. The new Patchell trailer tracks nicely and has no unpleasant effects on the truck.

The dashboard layout is very car-like, with a big, uncluttered instrument panel and a logical placement of most of the minor controls – apart from the skip-shift button, stuck way over near the windscreen pillar. Excellent climate control is a feature of the big Isuzu. The system can be set for automatic distribution, economy airconditioning or manually overridden for fan speed.

Minor storage is very well handled. It includes two gloveboxes, a wide shelf above the windscreen and a centre console box between the seats that offers a hot/cold storage compartment as well as recessed open bins on its top. The forward part of its lid also flips forward to provide a forward-extended tray.

The glovebox above the driver has had its lid replaced by a neat custom woodgrain-finished metal fascia that carries the communications equipment – CB, Fleetlink and a normal R/T, plus brackets for the handpieces. The job

has been done by Willie Malcolm of Rotorua, who does all of W&W’s work of this nature.

Cab entry has been well thought-out. The Isuzu has three handgrips in the door openings – two lowish (at seat base level) plus another little one midway up the A-pillar which is ideal for the second grab that would otherwise have to be on the steering wheel.

The Isuzu designers have obviously done a great job with the cab shape: It creates very little wind noise – you can even open the window fully and there’s still very little buffeting or noise.

So far so good, but there is one downer in an otherwise great package: The mirrors just aren’t up to it for this application. No matter how the left-hand ones are adjusted, about all you can see is the side of the truck – the trailer is barely in view. The thing about the mirrors is that they have all the nice extras like heating and washer/wipers – but you can’t see much with them! They really do need changing.

For the rest of the truck – and especially the revised transmission – the rating is now “Excellent.” T&D

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SPECSthe the trevor trevor testtest

ISUZU GIGA CYH530 8x4

Engine: Isuzu 6WG1-TCS

Capacity: 15.6 litres

Maximum power: 390kW (530hp) @ 1800rpm

Maximum torque: 2273Nm (1675lb ft) @ 1300rpm

Engine revs: 1610rpm @ 90km/h in 16th

Fuel capacity: 400 litres

Transmission: 16-speed Isuzu MXJ16-AMT

Ratios: 1st – 14.01, 2nd – 11.343rd – 9.93, 4th – 8.045th – 6.86, 6th – 5.547th – 4.58, 8th – 3.719th – 3.06, 10th – 2.4711th – 2.17, 12th – 1.7513th – 1.49, 14th – 1.2115th – 1.00, 16th – 0.81

Front axles: Isuzu I-beam, rated at 6400kg each

Rear axles: Isuzu RT210, combined rating of 21,000kg

Auxiliary brakes: Isuzu exhaust brake plus magnetic retarder

Front suspension: Taper leaf parabolic springs, shock absorbers, stabiliser bar

Rear suspension: Isuzu parabolic multi-leaf springs, shock absorbers

GVW: 29,000kg

GCM: 65,000kg

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AVAILABLE AT YOUR ISUZU DEALER NOW

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