How to reduce the malfunctions of four-wheel drive tractors? Correct use of the front drive axle is the key.

I. When transporting on hard surfaces or driving without a load, it is strictly forbidden to engage the front drive.
When a four-wheel drive tractor is transporting goods on hard surfaces or driving without a load, the front drive axle must not be used, otherwise it will cause premature wear of the front tires. The front drive axle can only be used when the road surface is slippery due to rain or snow, or when the rear wheels slip when going uphill. After the tractor passes through difficult sections, the front drive should be immediately disengaged. There was once a case where a user in Shandong bought an 804 tractor and happily drove it back to their home over 30 kilometers away. After checking the vehicle at home, they found that the front tires were worn. The user immediately called the dealer to report the situation, and the dealer sent a service personnel to the user's home. Upon inspection, the front drive was still engaged! The service personnel then provided on-site training to the user, emphasizing that it is strictly forbidden to use the front drive axle when transporting on hard surfaces or driving without a load.
II. When performing heavy-duty field operations or working on wet and soft soil, the front drive axle needs to be engaged.
When a four-wheel drive tractor performs heavy-duty field operations or works on wet and soft soil, in order to improve the tractor's adhesion performance, increase its traction, and enhance its operational adaptability, the front drive axle can be engaged to use four-wheel drive. When engaging or disengaging the front drive axle, the following procedure should be followed:
1. Depress the clutch pedal with your left foot, engage the transmission gear, and then slowly release the clutch pedal. When the tractor starts to move slightly, promptly push the front drive axle control handle forward to switch from two-wheel drive to four-wheel drive.
2. When stopping or changing gears, depress the clutch pedal with your left foot, first move the front drive axle control handle to disengage the front drive axle, then shift out of gear and stop the engine, or engage the required gear.
3. During transportation operations, the front tires wear out faster, and the wear on the left and right sides of the tire tread may be uneven. In this case, the left and right tires can be switched according to the situation, or the two front tires can be installed in reverse (not in the forward direction of the tread).
III. Do not arbitrarily change the size of the front and rear tires.
When a four-wheel drive tractor uses the four-wheel drive function, theoretically, the linear speeds of the front and rear wheels should be exactly the same for optimal performance. However, in actual design, due to the non-infinitely variable speed of gear transmission, it is impossible to achieve perfect consistency. Therefore, when using it, there will be inconsistencies in the front and rear wheel speeds, meaning either the front wheels will be faster or the rear wheels will be faster. This will cause parasitic power in the tractor. If the parasitic power is too large, the tractor will be unable to operate normally. Therefore, the design generally requires that the front and rear wheel differential speed does not exceed 3%. Arbitrarily changing the size of the front and rear tires will cause the front and rear wheel differential speed to be too large. This may cause premature tire wear, or in severe cases, damage to the front drive transmission system gears, rendering the tractor unusable. For example, if your four-wheel drive tractor has 14.9-26 tires on the front wheels, only the same model of tires, also 14.9-26, can be used when replacing them. If 14.9-28 tires are used, this will cause premature wear of the front tires or more serious failures.
IV. The four-wheel drive tractor has a smaller front wheel caster.
Compared with two-wheel drive tractors, four-wheel drive tractors have a relatively smaller front wheel caster. The caster of two-wheel drive tractors is usually 4-10 mm (different models have different standards, please refer to the manual for details), while the caster of four-wheel drive tractors is usually 0-5 mm (different models have different standards, please refer to the manual for details). If the caster is not adjusted properly, it will affect the vehicle's steering performance and cause abnormal tire wear. The caster adjustment is achieved by adjusting the length of the steering tie rod. When the tractor is driving straight on a flat road, measure the distance between the centerlines of the two front tires at the front and rear ends of the tire centers over the center point, making the front end B - rear end A = 0-5 mm. After adjusting the caster, be sure to tighten the lock nut on the tie rod. In addition to the caster, to prevent premature tire wear, it is also necessary to ensure that the tire inflation pressure meets the requirements of the specification.
V. Maintenance of the front axle
According to the maintenance requirements, regularly lubricate the front axle swing shaft, drive shaft bearings, kingpin bushings, front axle central swing pin bushings, steering cylinder joint bearings, and tie rod ball joints with grease. Check whether the tie rod ball joint nuts and cylinder end pin nuts are loose. The general inspection cycle is 50 hours. The first change of front axle lubricating oil is at 60 hours (break-in period maintenance), and after that, the front drive axle case oil level should be checked every 500 hours and added if necessary. The front drive axle lubricating oil should be changed every 1000 hours.