Authored by: Tractor tyre expert | 30 November 2021
Your agricultural tyres are wearing parts which are placed under very heavy strain; they do not require particular maintenance, but a regular check-up and a good measure of vigilance can help you make them last much longer. It may not seem worthwhile, but if you get into the habit of doing a ten-minute check-up regularly, you will be able to detect any problems well before any damage occurs and take remedial action to make sure that you can always work in the best conditions.
To avoid bad surprises during your agricultural campaigns which could immobilise your tractor, it is highly advisable to carry out a visual inspection of certain parts of your tyres to detect any irregularities or warning signs of wear.
A rapid visual inspection of the sidewalls and tread will reveal any cuts, hernia or traces of a impact on the tyre.
This is an abnormal bump which forms generally on the sidewall of the tyre. It may be caused by a lateral impact, a root, stone or branch.
A hernia cannot be repaired, so you may as well replace the tyre to avoid any risk of accidents or immobilisation with work in progress.
A hernia often corresponds to a break in the inner lining of the tyre (photo on the right)
Generally, slight cuts on the lug base or tip of the lugs which do not pose a problem. On the other hand, deeper cuts must not be neglected, wherever they are situated on the tyre.
If you come across a very deep cut, it's wiser to remove the tyre to check that the structure is not really damaged.
BEWARE: If a cut is due to a frontal impact, a jagged piece of metal or sharp object… it is possible that the casing has suffered more internal damage than is visible from the small external nick. An internal inspection will be essential in this case because the tyre could burst during pressure adjustments.
These appear in the form of regular creases on the sidewall and may be caused by frequent flexion and deflexion or linked to storage of deflated tyres during the winter, driving with a flat tyre or extended use of underinflated tyres.
This is a sign of fatigue, and your tyre should be replaced.
The following check-up concerns the inspection of the rim. A rapid visual inspection around the rim area, above all at the level of the bead seat, makes it possible to check if it is clean or whether there are traces of an impact.
The bead area is a more fragile part of the tyre, and it is important to check that a knock has not damaged the bead or to avoid, as far as possible, accumulation of detritus or small stones which could lead to a loss of airtightness with the flexion and deflexion of the tyre.
Break in the rim disc
The rims, which are generally made of steel, may be damaged during intensive use in difficult conditions.
The movement and flexion due to daily use, and impacts may provoke small fissures and corrosion on the sensitive parts of the wheels.
To avoid unpleasant surprises, it is important to check the presence or progression of corrosion on the rims and more specifically on the wheel bolts.
The problems which arise frequently concern the deformation of the bolt area, which is often due to automatic unscrewing, or incorrect tightening during repairs, leading to looseness and friction between the joint threads as well as corrosion.
This type of problem can lead to disassembly and cause heavy vibration when driving. To remedy the situation, just remove any rust and adapt the tightening of the bolts regularly.
This detail is often neglected by many farmers because the cap seems to play only a superficial role. However, the valve is the weak point which permits the flow of air and, depending on how tight it is, it makes it possible to contain the pressure in the tyre. The cap is what protects this weak point.
Without a cap and following a badly placed impact to the valve core, even a slight knock, airtightness can diminish immediately, leading to loss of pressure and the risk of driving with underinflated tyres, which could destroy the tyre’s casing and cost far more than just a valve cap.
Your agricultural tyres face different strains on a daily basis. You must regularly check for foreign bodies on the sidewalls, tread or at the level of the bead, such as branches, earth, stones, etc. These may bring a risk of corrosion of the rim, ore more frequently a problem at the level of the bead.
When you carry out your inspection, make sure that the contact area between the edge of the rim and the tyre bead is not damaged. The presence of foreign bodies at this level can cause damage linked to the permanent flexion and deflexion of the tyre when you drive. In any case, you should make sure that your tyres are cleaned regularly and get rid of dirt after each use.
When you discover irregular wear at the level of the lugs, in most cases this is a sign of incorrect parallelism.
Agricultural tyre wear may be of mechanical origin, which is to say that it is linked to incorrect adjustment of the axis of the two tractor wheels compared to the centreline of the tractor.
Wear linked to incorrect parallelism
Checking parallelism is a simple and rapid operation. It allows you to establish the type of geometrical problem you have and to extend the useful life of your agricultural tyres by making a minor adjustment.
Irregular wear to the tread may also be due to wear to the axles, pins or bearings.
There may also be irregular wear to the rear axle, which is generally due to misalignment of the trailer axles during intensive use on the road.
Checking tyre pressure is vital and obligatory if you want your tyres to resist the load and allow you to work in the best possible conditions.
Part of the check-up can be carried out when driving, just after the static check-up. When driving, you must pay close attention to abnormal vibrations, to road handling and to any lateral sway.
Because of the different types of strain placed on your wheels on a daily basis: ruts, heavy ground, rough terrain, etc...
It is relatively normal for there to be slight shifts in the settings and vibrations when driving are often the result of incorrect parallelism which will cause the rapid deterioration of your agricultural tyres:
Just like abnormal vibrations when driving, a problem with directional stability is often caused by an error in parallelism.
The progressive geometrical imbalance at the level of your agricultural tyres depends on your use of the tractor. When you identify one of the following problems, this is certainly linked to parallelism:
A left/right sway effect when driving may be linked to several causes, but the most frequent are as follows:
The tyre may have been incorrectly installed on the rim seat, the bead is badly positioned which leads to this swinging movement only when driving at speed.
The rims may not be perfectly round and bigger than the reference size. A rim which is slightly oval can cause this abnormality when driving. It will be necessary to change the rim to avoid wearing the tyre too rapidly.
Tool for measuring tyre concentricity
There may also be a tyre manufacturing imbalance with a slightly oval shaped tyre. Your tyre dealer has equipment to check tyre concentricity (perfectly identical radius for all measurements from the centre).
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