New Holland’s CX straw walker combine has been around since 2001. With decent used examples on the market, Geoff Ashcroft runs through a checklist.
Built in Zedelgem, Belgium, New Holland’s CX straw-walker combines date back to 2001, when the sleek-looking CX700 and CX800 range stepped in to replace the popular TX models as the new flagship straw walker harvesters.
Where the CX7 models came with five straw walkers, the wider CX8 gained a sixth walker and more output. They arrived with a new cab, boasting improved visibility, more space and more operator comfort, and the ability to offer the firm’s precision farming PLM compatibility.
By 2007, the six-walker CX flagship had evolved to the CX8000 Series comprising CX8070, CX8080 and CX8090 models. A smaller CX8060 arrived too, built on a five-walker chassis and with a smaller grain tank.
This introduction was pushed by engine emissions regulations to achieve EU Stage 3a compliance, and with it came greater functionality with its Intelliview II monitor.
The key differentiation across the top three models was engine power.
Three years later, the range gained EU Stage 3b compliance with selective catalytic reduction technology, resulting in a claimed 10 per cent reduction in fuel consumption.
Around this time, chaff blowers were dropped in favour of spinning discs, avoiding the need to run the straw chopper when swathing.
At the same time, the cab interior was overhauled and the Intelliview III, colour touch-screen monitor arrived to make the most of the new Multi-Thresh separation system and real-time moisture sensing.
By 2013, the CX range gained greater sophistication and performance with the firm’s Opti-Speed auto-adaptive variable speed straw walkers, along with Elevation badging. Opti-Clean and Opti-Fan systems were also introduced.
In 2016 the CX8.70, CX8.80, CX8.85 and CX8.90 models arrived, complete with HarvestSuite cab.
To find out what to look for in a used CX, we seek the expert advice of Oakes Bros combine specialist Scott King, who walks us round an eight-year-old CX8070.
THE CX is equipped with its fair share of electronics. Mr King suggests unplugging the main multi-plug connectors and checking for corrosion.
“There is a good amount of sealing in the plugs, but any corrosion will throw up error codes and warnings, as if the world is coming to an end,” he says.
“They may just need cleaning and reconnecting with a dab of electrical grease.
“Sensors are robust, but potentiometers can give false readings, though the Intelliview monitor will point you to a specific ‘X’ number, which can be easily traced on the wiring looms.”
THIS 2011 model is powered by an EU Stage 3b Cursor 9 engine.
The engine is shrouded by a lift-up steel panel, which is designed to help airflow across the engine, avoiding the build-up of debris and dust that can lead to thermal events.
A fixed displacement cooling fan is belt-driven, so pay attention to the belt condition.
Also check the intercooler’s rubber connecting hoses for splits – they can perish and leak, reducing power. Engine boost pressure is shown on the in-cab Intelliview monitor, but you will not really know until the combine is put to work and the engine is fully loaded.
Only three oils are used for the entire machine, which simplifies maintenance; engine oil, hydraulic oil and an EP90 for gearboxes.
Bolted to the engine’s tailshaft is the main hydraulic pump assembly – check the fill-pipe. Early models used a three-piece fabricated pipe that can become fatigued and crack, allowing hydraulic oil to splash out.
Later models gained a mandrel-formed pipe which is up to the task.
THE CX’s elevator comprises four chains and three rows of bars.
Elevator bars are a service item, says Mr King, and any bent items should be replaced, along with nylon wear skids that the bars sit on.
Feeder housing can be removed using a tractor threepoint linkage to provide access into the threshing drum, beater and rotary separator. Not all bearings are greasable, though many can be hidden behind covers, so be prepared to look.
Check de-awning plates on the main drum, as their bolts can come loose if neglected. Inspect concave wires too - they can become bent and eventually break off, especially if the combine has spent its days in a stony region. Horizontal concave bars should reveal square-edges, unless very badly worn.
Hanging behind the main drum is a grain curtain that deflects grain onto the sieves.
“Look through the right-hand access plate to check that it is in-situ,” says Mr King.
“The rubber hinge that secures it can perish and that means the curtain will drop off and rest on the sieves.”
THE CX8070 uses a split grain return system, pushing crop back into the threshing system on both sides. Drive pulleys on both sides sit on a keyway, which is not greasable and can wear in time.
Mr King says: “Check both pulley fitments by grabbing with both hands and feel for excess play.
“If left untouched, a loose pulley can cause the key to eat into the shaft, leading to a larger repair.”
Grain is fed into the return auger through concave re-threshing plates. Check their teeth for excessive wear, and then reset with an 8-10mm gap.
Too tight and grains become cracked, and plates will wear rapidly. If set too loose, they will not work properly and will return too much material.
The main elevator tension is also an area to check, and with the bottom cover undone, inspect elevator flight condition.
“Straw walkers are a fit and forget part of this model,” he says.
“Unless something has gone through the combine, they will barely need touching.”
THERE are a lot of belts on the CX8070.
Be prepared to slacken them one by one, to allow thorough inspection for cracks, splits and missing sections, to determine any that might need replacing.
Belt tension is easy to set, using a spring and nut that is tightened to align the nut with a plate.
Spring coils will give an idea of remaining life for tensioning too. Chains are set in the same way.
Grab a section of links and push, then pull, to feel for wear.
Any areas of concern will mean chain replacement, as will sprockets showing razor-sharp teeth profiles.
On the right-hand side of the combine, Mr King recommends changing the bubble-up auger’s chain drive at the start of every season. It is tucked behind the top of the grain elevator.
“They are known to fail if left untouched,” he says.
“And if they do fail, the first warning sign is a slow fan speed – and then you will have a lot of grain to shovel to clear the machine.”