John Deere’s 6M series was launched late last year as a replacement for its ‘standard’ specification 6030 series tractors. This followed on from the earlier introduction of the firm’s higher specification 6R series.

There are six models in the line-up from 115hp to the new flagship 170hp 6170M. The two largest models in the series feature six-cylinder engines while the remainder are all four-cylinder units.

For this test, the Irish Farmers Journal borrowed a John Deere 6140M from TFM in Enniscorthy, Co Wexford.

The 6140 is the largest four-cylinder tractor in the line-up with a Stage IIIB compliant 4.5-litre PowerTech PVX engine.

This engine develops 140hp at a rated engine speed of 2,100rpm; maximum horsepower is quoted at 147hp. Maximum torque of 640Nm is developed at 1,400rpm; that is 100rpm lower than that of the three smaller four-cylinder models which develop their maximum torque at 1,500rpm.

Interestingly, the 6140M is a bit unusual in that it has a four-cylinder engine in a six-cylinder chassis. Many manufacturers are trying to do the opposite by creating ever more powerful short wheelbase four-cylinder tractors.

The 6140M is bucking that trend by dropping a four-pot motor into a six-pot chassis.

Clearly, the company feels there is a demand for such a product so what has it got to offer customers?

Despite a shorter test than normal, we still managed to put in two full days exploring the potential of the 6140M. Unfortunately, it did not allow us enough time to do a dyno test, but it was an interesting performer nonetheless.

First impressions

The John Deere 6140M appears to be a big tractor but weighs in at just 5,534kg and has a wheelbase of 2,765mm. Our test tractor was fitted with Firestone 540/65R28 tyres on the front and 650/65R38 tyres on the rear.

It has the latest R series styling, including updated cab, cab lights and instrument cluster.

While the cab is improved, the manufacturer has stuck to a conventional six-pillar design with standard door and opening side windows. The R series gets the new four-pillar cab.

Whether on the ground or up in the cab, the bonnet looks huge. This is partly due to the fact that this is what the company describes as a ‘diesel-only’ tractor.

To meet the latest round of emission regulations, the company had to add a diesel particulate filter (DPF) to the exhaust system. The DPF unit catches the soot particles in the exhaust gases and burns them through a process called re-generation.

The DPF unit works in conjunction with exhaust gas recirculation (EGR) and a variable geometry turbocharger (VGT). A diesel oxidation catalyst (DOC) is combined with the DPF unit.

Transmission options include 16/16, 20/20 or 24/24 in PowrQuad variants and 20/20 or 24/24 in AutoQuad Plus variants.

Our test tractor had the 24/24 (forward/reverse) AutoQuad Plus, 40kph transmission. This gives six physically selected gears with four powershift speeds in each and (selectable) automatic gear shifting within the powershift speeds.

Auto gear shifting is selected and de-selected by a button on the gearstick. A de-clutch button has now been incorporated into the gearstick to facilitate range changes without pressing the clutch pedal.

In keeping with all things Deere, a park position is also included into the gearstick gateway as well.

The M Series hydraulics have also received a makeover to provide more power and faster response times.

Four-cylinder models feature an 80-litre/min pressure compensated system, with the option to fit a 114-litre/min pressure and flow compensated version. This is fitted as standard to six-cylinder models.

Maximum rear lift capacity is quoted at 6.3 tonnes

Up to four double-acting spool valves can be fitted. Our test tractor had three mechanically-operated spools with adjustable flow control.

It was also fitted with the optional shiftable 540/540E/1,000rpm speed pto plus optional front suspension.

Other options from the manufacturer include the fitting of front linkage, pto or a choice of John Deere loaders.

Management and control options available include ISObus and GreenStar-ready wiring plus the iTEC Basic headland management system.

View from the seat

From the cab of the 6140M, it feels like a very big tractor for 140hp. The bonnet area is huge.

Access through the conventional door was good for my ever-expanding frame. In the seat, there is something very familiar and comfortable about the 6140M, a bit like the earlier ’00 or ’10 series.

The new dash and analogue instrument cluster is easy to understand. Controls are simple, obvious almost, and well laid out.

You don’t have to be a rocket scientist to make the 6140M move or operate any of its functions. It is an easy tractor to get to grips with.

One gripe I have, which is shared across many manufacturers, not just Deere, is that there is no simple rocker switch control of the lift.

In my opinion, this is essential for safe control and operation of the lift and pickup hitch when yoking to an implement or trailer.

In addition to the driver’s air seat, the passenger seat also featured suspension. Other creature comforts included air-conditioning and lots of lights for night work.

There are lots of little pockets to store knives, phones and any of the tools of the farming trade. A pillar-mounted cup holder makes a nice home for a few tools.

Getting down to work

First on the list of tasks was a very big ask for the John Deere 6140M. We yoked it to a three-metre Kühn Cultimer deep-cultivator but, without weights, we didn’t really expect much.

It lifted it no problem but even this tractor with a six-cylinder frame needed some serious ballast out front to go anywhere with it.

A more realistic challenge came in the form of a Vaderstad Carrier 500 cultivator with two rows of discs, levelling paddles and packer roller. Operating on rape stubble ground, the Deere surprised us all.

While the ground was dry, there were some serious hills to contend with. The little DPS four-pot motor absolutely excelled.

The four powershift speeds provided enough scope to operate the Vaderstad without range changing. Overlap between ranges was slim, almost limiting, but the little DPS engine more than compensated for it. Overall, we were very satisfied, surprised even, with the 6140M’s in-field performance.

Our next task for the 6140M was a six-mile run up and down some serious hills with a twin axle trailer loaded with oats.

While not a massive load, it was enough to test the 6140M’s mettle.

Yoking to the trailer was straightforward with the standard telescopic hitch. The telescopic element operated from one of the tractor’s spool valves. When not in use or the spool is required for another task, a simple bracket keeps the hitch coupling tidy and safe.

All set for the road and telescopic mirrors plus an interior mirror help keep an eye on things behind.

Selecting the appropriate gear for take-off and the little engine did not disappoint with low down grunt.

Shifting up through mechanical gears on the road was slick enough but it is a good stretch to operate the gearstick at its furthest away point.

Once in ‘top’, the four powershift speeds could be set to operate in auto shifting by selecting the autoshift button on the gearstick.

A dial on the right hand console allows the operator to adjust the power-shift gear changing point between ECO (fuel saving) and power positions.

This autoshift worked very well with the empty load but fully loaded, it felt like it dragged the engine down a bit too much before changing power-shift speeds.

That said, it is a very useful feature on the road and is very easy to activate or de-activate so the tendency was to use this feature as much as possible.

Overall, the 6140M performed very well on the road, was comfortable, perhaps helped by its long wheelbase. Again, its long wheelbase should benefit when handling some of the bigger slurry tankers now being used.

Being a long wheelbase tractor, we were concerned about its manoeuvrability and the company does not provide any figures for its turning circle.

So with trailer still yoked, we put it through our chicane test. Not sophisticated, just an old haggard designed for much smaller tractors in two-wheel drive.

Again, the 6140M surprised us. It is not as big as it looks and is certainly far more manoeuvrable than you might imagine.

Despite the large bonnet filling much of the front windscreen and ‘B’ pillars in the cab, visibility was not an issue overall. You could see the inside track of the front wheels to follow field markings so no complaints.

Fitting a loader will certainly affect visibility. It will require careful selection for the best option from not just Deere but other loader manufacturers.

Overall impression

First impressions from outside the 6140M are that it is a very big tractor for 140hp due to the need to accommodate both the engine and DPF unit.

In design, it is certainly different in that it uses a four-pot engine in a six-pot chassis. Deere still uses a six-pillar cab design and while maybe not offering the visibility of newer designs, it still does the job nicely.

Having driven it, I think that this concept works well for this tractor’s target market sector, the larger dairy farmer or mid-sized tillage farmer/mixed farmer.

It’s not too big for a loader and proved to be capably manoeuvrable, but without manufacturer’s figures we cannot be specific.

The four-cylinder tractor will give the economy of a four-cylinder tractor, which is very important with fuel prices the way they are. Yet, you get the stability of a six-cylinder tractor. And despite its apparent size, it is not heavy – far from it.

Maybe just a generation thing (my generation), it is quite retro and the cab is simple in design which I think is just another element that adds to its appeal.

If fitting a loader, take care to select one that offers best visibility as well as meeting all the other loader criteria. A clear roof panel is available for €160 plus VAT and it’s worth considering if fitting a loader.

Serviceability

Daily checks are very easy to carry out on the 6140M. Oil level, coolant level and radiator screens are all easy to hand. Access to service items is a little trickier around the engine in particular.

Side panels can be removed to gain access but require removing an addition plastic block to allow the steel side panels to slide off their hinges.

The air filter is mounted on top of the engine and may require a cherry-picker to access. Once panels are removed, access is unhindered. The transmission and hydraulic filters are easy to access as well.