When bring the silage making process in house, there are a number of options for grass processing machinery, however, the forage wagon remains a popular choice. Alex Heath takes a look at what needs considering when buying a used wagon.
For many livestock farms, the silaging process is outsourced to contractors with high capacity self-propelled forage harvesters. However, taking control of the process and doing it in-house can be an appealing concept, with more control over quality of grass and pit compaction, along with timeliness of the cuts.
The options of DIY silaging on most farms then boils down to either a pull-type forage harvester, an ageing self-propelled or a forage wagon. The latter is particularly appealing to many, especially when you take into account the relatively small amount of labour required to carry out the operation with a wagon.
However, like all new farm machinery, forage wagons can be expensive, especially for those trying out this method of silaging for the first time. So, could a used machine be a sensible choice to get on the forage wagon ladder?
To see what you need to consider when looking at a used forage wagon, we took a trip to Devon-based Forage Wagons South West, owned by James and Deborah Boundy. The couple have been in the wagon business since 2007, selling new and used machines of all sizes and colours.
Deborah says the biggest consideration that needs making is the wagon’s workload.
“There is a big difference between the build quality and features seen on wagons designed for a farmer doing 20 hectares per cut and a contractor-grade machine for a high workload. However, we would always advise to go for the contractor-type machine for anything over 20ha as they are generally better built and more reliable.”
The pair says that more often than not customers have in their minds the size of machine they require, rather than the type of machine, which is arguably more important. James says: “The difference between a contractor and farmer machines is most notable in the running gear and drivelines.
“Farmer machines tend to sit on eight stud axles and have smaller tyres, whereas the contractor-type wagons have 10 stud commercial axles, often with air brakes, a rear steering axle and gearbox transfer of power to the rotor, rather than chain and sprocket drive on farmer-spec machines.
“Likewise, when comparing machines make sure spec is like-for-like, otherwise the price difference between them can be substantial.”
While many of the pointers are generic, relating to all makes of forage wagons, certain ones have their own common issues.
When purchasing a wagon, check the condition of the ring hitch for wear. Typically wagons will leave the factory with a 40mm ring. If that has reduced by 25 per cent it will need replacing. Newer wagons may have a spoon coupling, which tend to wear less. Inspect the hitch assembly and check for cracks and excess wear around the ride height rams. James says older Claas wagons can have cracking on the join between the ram piston and the slot that the ram works against.
All modern wagons will have a wide angle pto on the tractor end. Check for play in the universal joint. In addition, Pottinger wagons tend to have a second wide-angle UJ on the machine end. James says this gives a smoother transfer of power, but comes at a cost as the assembly is dearer to replace. Check for ‘slop’ between the cup and ball of the UJ.
The first area all wagons differ substantially is the pickup.
Pottinger wagons run a double bearing cam track, meaning they have 12 bearings on the tine bars in total. Find out when these were last replaced as it is a timely and costly job to replace the bearings which cost between £35 and £40 each. Likewise, Claas wagons have a double cam, with 10 bearings in total.
Lely, Krone and Strautmann wagons all run a camless pickup, which is simpler to maintain.
Check the condition of the tines. Most have tines arranged in straight lines on the bars, which allows for easier checking of presence and condition, however, Strautmann wagons have them staggered in a ’V’ formation. Any bent tines will lead to excessive wear of the pickup bands. James says a number of used wagons are now coming to the market with plastic bands. These have less squeaking from metal on metal contact and a lower power requirement as there is less friction.
Replacing pick up bands can be a costly job, with Pottinger about £20 while Strautmann are nearer £40. Lely has galvanised bands at about £18.
Drive to the pickup is typically chain and sprocket, although Strautmann wagons are shaft driven. Protection is provided by a slip clutch, so check the condition of this. Being caked in old grass is a tell-tale sign that it has not been regularly serviced, says Deborah.
Most wagons feature a gearbox and shaft affair for transfer of power from the pto to rotor, however, some smaller models have a chain and sprocket transfer. If it is the later, check the condition and tension of the moving parts. The former is a more robust and reliable method says James. Check the level and condition of the gearbox oil.
Rotor construction differs considerably between brands, in particular the finger width; Pottinger’s is from 8mm depending on the model, while Strautmann has flat plate welded on the leading edge, giving a 20mm width and Lely has a similar arrangement at 25mm. While a wider finger may give a cleaner chop, they conversely have less clearance for foreign objects, especially broken pick up tines, says James.
Examine all fingers are straight and listen for any knocking when the machine is running. Bent rotor fingers can be replaced but can be a time consuming job, says Deborah. Pottinger machines are harder to repair but need doing less frequently, says James, as the rotors are a two-piece design and require vertical welding, whereas Lely rotor sections come in three pieces and can be welded in horizontally.
The most important part of the forage wagon is its knife bank. However, it is tucked under the machine and spends the majority of its life soaked in silage liquor, so the maintenance and servicing on it is a good indicator of how well the rest of the machine has been looked after, says James.
All wagons run spring protection for the knives and the condition of these and the knife holding assembly is critical to its function. Pottinger’s knife bank is a particularly fiddly and expensive to repair, for example, with the hardened pins holding the knives in place costing about £40 a piece.
Lely wagons feature a break back closed spring, which are prone to a lot of wear, however, they are easy to replace in the field, says James. If there are gaps emerging between the spirals in the spring, it is probably time to replace them. However, also check the uniformity of the springs; you will be able to tell by the amount of rust which ones are older. The Lely wagon also has a more open knife bank that is easier to clean out regularly, says James.
The Strautmann knife bank has lots of individual parts, some of which are not available to purchase individually, only as a complete assembly, so check when it was last serviced and that all parts are still intact as the cost of this can mount up.
Knives are a common wearing part and require frequent sharpening. Check the condition of the knives and observe how uniform they are. Some may have been replaced due to stone damage, however, if there are a mix of different wear rates, consider a new set. Likewise, if the serrations are dull or non-existent, a fresh set is needed.
There are manufacturer-supplied and non-genuine knife options. Deborah says there is little to split the genuine from non-genuine in terms of quality. Some wagons have reversible knives that effectively double the life of the knife, providing they do not break. Non genuine knives are typically between £20 and £30, while genuine Lely knives are about £35 while Strautmann are £45.
Older wagons often had a two-chain discharge system that was prone to bending the discharge bars, however, newer wagons feature a four-chain system with two sets of staggered bars.
Little tends to go wrong with newer systems, says James, but check that bars stay perpendicular to the sides when discharging and all bars are straight.
A nice feature to have is two speed unloading, speeding the job up and a popular option on new wagons these days, says Deborah.
Check all boards forming the floor are in good condition. The combination of silage juices and spending time outside can rot the wood at different speeds. Some newer wagons will have a stainless steel floor, but these are likely to command a premium price.
Have a good look underneath the wagon and check for any cracking where stress may occur, namely where the running gear is attached and around the front end. James says Strautmann wagons seem to suffer stress fractures the worst. Lely wagons also feature a galvanised chassis that helps protect against corrosion.
Of critical importance is the condition of the axles, suspension and tyres.
Lely wagons feature two large springs that fix the axles to the chassis, however, most feature a rocking bogie and individual leaf springs. Check all are intact and none have cracked.
Replacing tyres on wagons is no small expenditure, so condition when buying is important. Most will be running on 22.5-inch rims, although some of the larger wagons now sit on 26-inch rims. The smaller have the advantage of allowing a super single rim and tyre to be grafted on if a puncture occurs in the middle of the campaign.
Observe the wear across the tyre. Wagons with a rear steering axle should show more even wear across all four tyres, be kinder on the ground and require less power to turn. Excessive wear on the shoulders is an indicator that the tyres have been run at a lower than optimal pressure.
The body should be relatively straight and free of too many knocks and scratches, although James admits accidents that can sully the paint work, do happen.
In the case of the Lely wagons, a pivoting headboard allows the wagon to have a shorter overall length. While filling, the headboard is vertical. As it nears capacity, the headboard pivots forward. When emptying, the headboard then pushes back as the crop moves rearward. While this means more grass can be held over the drawbar, it is a weaker design overall.
A tell-tale sign of an inexperienced operator or frequent over loading is a bowed tail board. If this is the case, James says extra stresses will have been put through the rest of the driveline, including the rotor, gear boxes and discharge gear.
Claas, Krone and Strautmann machines have a locking mechanism for the tail board, as opposed to the up and over arrangement of Lely and Pottinger. The former has the advantage of sealing tighter for other products such as wood chip or maize, however, if out of alignment they take more effort to right and often the chopping unit will not engage if it is not shut tight.
Additive applicators can be a make or break for some customers, says Deborah. However, the difference between having one fitted or not can see about a £1,400 difference, as that is what a newly installed system costs. DIY versions can be made for less.
However, James says having an additive system fitted is not always a positive as extra liquid is introduced into the machine, potentially causing more corrosion and wear.
Much like tractor model numbers, some of which vaguely relate to the power rating, forage wagon manufacturers also have wide array of labelling methods for their wagons, some of which include the cubic capacity (DIN), capacity with medium compression and length of the body.
While Strautmann uses the rough physical capacity of its wagons, Pottinger uses the length of the body to number its models, while Lely give the figure with a medium level of compression applied to the crop.
The most accurate way of comparing sizes of wagons is to use the DIN number, which is a standardised way of measuring volume.