Though outward appearance may not suggest much has changed, there are several updates lurking beneath the skin of Claas' latest Arion tractor models.
Now in its fourth generation, Claas' latest Arion 600 Series boasts more power with a new top model taking the range up to 205hp.
As well as the addition of the new Arion 660, Claas has also been busy updating several other key aspects of the venerable Arion range, as revealed at a launch last July.
This includes new front axles, cleaner engines, a new cab frame option and the development of a new intermediate control specification level.
To determine the impact of the updates, we tasked the top model 660 with a variety of silaging duties.
TRANSMISSION
AS the power rating of the new Arion 660 goes beyond the capabilities of the Arion's powershift transmission, only a continuously variable transmission (CVT) is available in the 660.
Unlike the CVTs used in its larger Axion and Xerion tractor models, the Cmatic CVT in the 660 is Claas' own design and build. It is effectively a two-range transmission, but unlike other two range competitors, this one does not need to stop to change range.
Instead its two hydrostatic units both share pump and motor duties.
In combination with some clever clutch work, this allows the tractor to seamlessly achieve speeds from 0-50kph. It is smooth too, with the range changes hardly even registering on the senses.
In terms of operation, it uses the same principals as Claas' larger tractors. Via pedal or stick modes, the CVT can be operated in one of three ‘virtual' ranges, with the upper limits of each range adjusted through the tractor's pillar screen.
Cruise
Within each range a cruise speed can also be set. Though easy enough to set and adjust, cancellation of a cruise will see all forward speed cancelled, meaning you have to cover this off with either the pedal or the speed control lever (stick).
We prefer other systems whereby a cruise can be cancelled with an intervening change in speed input from the driver, after which you can revert back to the cruise.
The workaround of this is to use two cruise speeds and toggle between the two; one for headland turns and one for work. But it is not ideal when it comes to negotiating obstacles, when all you want to do is shave a bit of speed off.
Helpfully, the transmission will hold the tractor stationary on hills, which makes pulling away from lights and edging out of blind gateways easier.
ENGINE
HEADLINE engine news is the Arion's extra power, now up to 205hp for transport duties.
Under the bonnet, Claas has stuck with a 6.8-litre Deere Power Systems engine for the 660. To meet emissions, all the abbreviations have been used, including EGR, DOC, DPF and now SCR with a splash of DEF.
This basically means it will need topping up every now and again with AdBlue.
Suffice to say it is a complicated engine, but one which rewards with impressive performance.
In combination with the transmission, the tractor's response to throttle and speed inputs is almost instantaneous, but smooth with it.
And as it is a CVT-only model, it means the tractor can make the most of its power and torque curves, with the transmission constantly adapting to work in the engine's sweet spot.
However, the engine memory speed function could do with engaging more softly, particularly when coupled to a pto-driven machine such as a rake.
As it is, it snaps into life, putting strain on the rake's driveline. Maybe the rpm build-up could be made adjustable, as too could the pto start-up.
The latter can be adjusted via a dealer, if necessary.
Economy and full power modes can be selected and droop levels adjusted. In economy mode this will put more emphasis on the transmission to compensate for reduced power, or in power mode, will see all the engine's muscle unleashed.
The latter is suited to pto work, while the former is an ideal fuel-saving strategy when carrying out lighter draft work, for example.
Access
Maintenance-wise, access to radiators is generous, with a wide opening cooling package.
Accommodating the AdBlue tank is a space under the left-hand steps. To access this, one of the left-hand steps hinges upwards.
Preventing any dirt falling through the step onto the lid/filler of the AdBlue tank, an angled plate is positioned under the step.
CAB AND CONTROLS
TWO versions of the cab frame are available - a new four-post design or the current five-post version - with no cost difference between them.
As with past experience, we find the extra post on the left-hand side of the latter provides a handiersized door for this size of tractor.
You also get an opening side window with it for a bit of fresh air.
Ever since its introduction in 2012, we have always got on well with the Arion cab. Though a bit clinical, it affords plenty of space along with an operator-friendly layout. And two new control specification levels only add to its appeal.
In particular is the new CIS+ package which sits in between its entry level CIS and top-spec Cebis variant. As tested by FG earlier this year, the CIS+ package affords a comprehensive set-up of tractor functions, without needing to step up to the full fat Cebis, but it is as simple to use as CIS.
With CIS+, all primary tractor controls are integrated into the right-hand armrest. For set up, a screen on the right-hand A-pillar is used. Featuring bold, clear graphics, it is not overfacing to get your head around and allows you to make the most of the tractors' functions, such as spool flow and timings, transmission settings and engine characteristics.
Views
And because CIS+ is only equipped with electric spools, it means the area to the right-hand side of the tractor is very open, affording good views all round. It is not a tractor which you feel cocooned in like some in this power bracket.
However, we would still like to see a couple of tweaks made to the cab. The right-hand armrest is particularly hard when leaning on it all day, and the dash could do with freshening up.
PRACTICALITIES
WITH reduced maintenance and an increased payload by 500kg, Claas has swapped out the previously used Carraro front axle independent suspension system for a fixed axle, ‘saddle' type suspension unit from Dana.
Though there is little discernible difference in comfort offered, the Dana axle, regardless of load will always return to a middle position, giving a consistent range of movement.
It also has only four grease points, and the wheel angle sensor is better protected.
In combination with its wasp waist-shaped chassis, the tractor can achieve an impressive steering lock, giving it a level of agility some four-cylinders would envy. Also up-front is a new set of external front linkage controls, giving control over raise/lower and one spool.
At the rear, linkage lift capacity has been given a boost by 500kg and there is now the option of 150 litres per minute load-sensing hydraulics.
Stronger
Additionally, the pickup hitch lift rods have been given a tweak to feature more travel and a stronger design for less wear and tear.
Also, given an increase in size, up to 1.95-metre diameter tyres can now be fitted.
Due to the inclusion of an AdBlue tank under the left-hand steps, the toolbox has been moved to the opposite side of the tractor. As a result, it is now larger and can be locked.
Though fit and finish of recent Arions has always been good, the firm has gone a step further and tided up some of the cable and pipe routing.
The tractors' back plate, home to various couplings, has also been moved closer to the cab, neatening up the rear end and improving rearward visibility, particularly to the pickup hitch.
FG VERDICT
WITHOUT doubt, the highlight of the Arion 660 is the interaction between the DPS engine and the Cmatic transmission.
It really is a hidden gem of a transmission in the industry - refined, reactive, and fairly user-friendly too.
Coupled with an uncluttered cab and well thought-out maintenance access, it really does stand out as an all-round good tractor, worthy of any shortlist.
If anything, all it is missing is an update to the look and style of the tractor, along with a refreshed dashboard area.
We think the subtle touches made to the Arion 400s would look well on the 500s and 600s.
