After the long and labour intensive start to the spring, it’s not too long ago that the thoughts of making silage seemed so far away. The shear work load on many farms seen maintenance of grass machinery such as mowers put on the backburner.

In the space of almost two weeks, the tables have turned completely as farmers play catch up and look towards silage season.

Ensure that discs are damage free and show no signs of play.

In this piece, we will be focusing on the more farmer orientated, mounted plain disc mower.

When it comes to maintaining machinery, it is clear that regular attention pays off. This can significantly increase the life of costly wearing parts.

Mower bed

Before and after washing the mower bed, inspect it closely for any obvious issues, faults or leaks in particular.

These should be easily spotted if the mower is clean and dry.

Cracks tend to occur as result of damage caused by collisions with foreign objects.

Depending on their location, repair may be an option.

The break back protection system should be working.

Also, ensure all discs are aligned at 90 degrees to each other.

If this is not the case, one of the gears may have slipped or that the disc was previously incorrectly installed.

If you know the mower bed oil is overdue replacement or unsure as to when it was last changed then consider changing it. Simply and safely, run the mower for a number of minutes to heat the oil up which will allow it to drain better.

All universal joints should be moving freely and greased.

Listen out for any unwanted sounds that may require further investigation. Once stopped, Open the drain plug and catch the waste oil, looking out for signs of metal particles.

Such particles indicate an internal gear or bearing issue that will require further attention and the need to have the bed flushed.

Then, fill the bed with the correct oil type and quantity as per manufacturer’s guidelines.

Do not over fill.

Discs, blades and skids

The hubs should be checked for excessive play. Do this by rocking each disc. If there is considerable play in any particular one then it should be replaced, otherwise it will only fall off in time. Often, fence wire can get lodged in under the discs and cause premature wear. If you happen to spot wire, remove it straight away. In some cases, it may mean removing the disc to gain access. The discs themselves should be checked over and showing no excessive damage or have chunks missing off them. Overtime, discs will wear thin and will need to be replaced. If discs are in good nick and not wafer thin, you can swap the inner discs to change their direction of rotation, almost doubling their service life.

The frame should be checked over for cracks or any damage.

Damaged discs may also cause vibration in the mower and lead to further damage. Ensure the top hats are securely bolted on. Mowers fitted with keyway or shear pin discs should be examined.

Check all blades that they are not damaging or scaring/scuffing the bed cover. A damaged disc or bend blade can cause this. Blades worn on one side can be swapped with a blade on a counter rotating disc. However, blades that are badly worn, bent or damaged should be replaced. Most blades have an arrow indicating the intended direction of rotation. Check the condition of the blade holders too. Consider changing the studs and nuts on beds with non-quick fit blades if worn or damaged. The skids on the underside of the mower bed should also be examined for wear and replaced if needs be. Uniform wear on all skids is a good sign showing that the mower is well setup. Worn skids will need replaced or if the mower is only occasionally used or used as a topper then skids can be gave a second life if plate steel is welded over the worn area.

The front of the skid, between each disc is very important as it also protects the bed, especially in the case of a blade bending backwards.

Gearboxes and driveline

Check all universal joints for play and grease them, especially the harder to reach ones. In an ideal scenario, slip clutches should be slackened off before storage to avoid seizure. When slack, check that the internal pads can move freely and that the clutch turns. After that, the slip clutch can be re-tensioned.

The condition of the skids on the under side of the bed should be checked.

PTO Covers and safety chains should be present and in place. The condition of drive belts and their tension will need inspection, where belts are fitted. Pulley bearings should also be checked for play. It is worthwhile carrying a spare set of belts as it is likely they will be needed at some point.

Gearboxes should also be checked over for play. Do this by removing the PTO shaft and wobbling the gearbox shaft. Significant movement means that an overhaul is required. Gearbox oil quality and level should also be checked. Milky white-coloured oil indicates the presence of water, indicating seal damage which should be further investigated.

Also, check for the presence of metal filings and if present budget for a new replacement gearbox. Gearbox oil should be routinely replaced as recommend by the manufacturer.

Swathing discs, skirts and other checks

Most plain mowers are equipped with swathing discs. If these discs no longer rotate then crop flow will be uneven. Having the discs bearing replaced will remedy this. All of the mowers panels, side skirts and canopy should be intact and free from damage. Small holes can be easily patched which should be done to prevent severe damage and avoid having to replace the skirt.

The frame of the mower will also need checked for damage or cracks which may have happened as result of a collision. Break back protection systems should not be seized. Check hydraulic fitting and rams for leaks or damaged seals. Although a simple device, the transport locking mechanism should be checked over that it is working properly.

When it comes to mounting the mower onto the tractor, ensure it is correctly setup and adjusted for both the tractor and terrain. This not only improves performance, but the longevity of the mower too. Daily throughout the working season, check blade and bearing condition and keep all grease points supplied with grease.