What do D1, D2, and D3 mean in an automatic transmission?

What are the three types of transmissions classified by operation method?

Transmissions can be divided into three types based on operation method: stepped transmission, continuously variable transmission, and integrated transmission. Stepped transmission: The stepped transmission is the most widely used type. It employs gear transmission with several fixed gear ratios. Depending on the gear train type, there are two kinds: fixed-axis transmission (conventional transmission) and rotating-axis transmission (planetary gear transmission). Passenger cars and light/medium-duty trucks typically have 3-5 forward gears and one reverse gear, while combined transmissions for heavy-duty trucks have even more gears. The number of transmission gears refers specifically to the count of forward gears. Continuously variable transmission: The gear ratio of a continuously variable transmission can change infinitely within a certain numerical range. Common types include electric and hydraulic (hydrodynamic) versions. The transmission component of an electric continuously variable transmission is a DC series-wound motor, which is not only used in trolleybuses but is also increasingly adopted in ultra-heavy-duty dump truck drivetrains. The transmission component of a hydrodynamic continuously variable transmission is a torque converter. Integrated transmission: An integrated transmission refers to a hydromechanical transmission composed of a torque converter and a geared stepped transmission. Its gear ratio can make stepless changes within several discontinuous ranges between maximum and minimum values, and it sees extensive application.

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How to Claim Insurance for a Flooded Vehicle Without Water Damage Coverage?

For vehicles flooded due to natural disasters or accidents, you can file a claim under the auto damage insurance. After reporting the claim, you will need to submit the required claim materials as per the insurance company's requirements. If the insured vehicle suffers direct losses due to flooding, the insurance company will be responsible for compensation within the agreed limits.

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Why does the noise persist after replacing the new belt when the air conditioning is turned on?

Replacing the new belt but still hearing noise when the air conditioning is on is due to insufficient belt tension or excessively high refrigerant high-pressure, or issues with the compressor's clutch. Choosing the appropriate air conditioning temperature: In summer, many people prefer to set the temperature very low. However, setting the temperature too low can affect health, so it's essential to adjust the air conditioning temperature appropriately. The most comfortable temperature for the human body is between 20°C and 25°C. Above 28°C, people feel stuffy, and below 14°C, they feel cold. Therefore, the air conditioning should maintain the car's interior temperature between 18°C and 25°C. Setting the temperature too low can easily make people sick. Do not immediately activate the internal circulation upon entering the car: When the car has been parked under the scorching sun for a long time, some car owners tend to turn on the air conditioning and activate the internal circulation immediately after starting the car, thinking it will cool down the interior faster. However, since the interior temperature is higher than the outside temperature, this approach is ineffective. Upon entering the car, it's better to first open the windows for ventilation and turn on the external circulation to expel the hot air. After the interior temperature has dropped, then switch to internal circulation.

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Do You Need to Wait for a Traffic Light When Making a U-Turn on a Dotted Line?

If the gap is marked with a dotted line, making a U-turn is not affected by traffic signals and does not require crossing the pedestrian crossing. You can make a U-turn directly as long as it does not interfere with other normally moving vehicles and ensures your own safety. If the gap is marked with a solid line, then making a U-turn requires crossing the pedestrian crossing and is subject to traffic signals. When making a U-turn that requires crossing a pedestrian crossing, you must yield to pedestrians: If pedestrians are walking on the right side of the pedestrian crossing and have not reached the centerline of the road, vehicles on the left side of the road should slow down and proceed cautiously, ensuring safety while allowing pedestrians to cross. If pedestrians are waiting outside the boundary line between motorized and non-motorized lanes and have not entered the roadway, vehicles should slow down and proceed cautiously, ensuring safety while allowing pedestrians to cross. If pedestrians have crossed the boundary line between motorized and non-motorized lanes, vehicles that do not stop and yield are committing a traffic violation and should be penalized. If pedestrians have entered the motorized lane (Lane A) along the pedestrian crossing, vehicles in Lane B should slow down and proceed cautiously, ensuring safety while allowing pedestrians to cross. If vehicles in Lane A do not stop and yield, it is a violation and should be penalized. If pedestrians are waiting at the centerline of the road without entering the motorized lane, vehicles that do not stop and yield are committing a violation and should be penalized. If pedestrians have crossed the centerline of the road and entered the motorized lane, vehicles that do not stop and yield are committing a violation and should be penalized. If the road is divided by a green belt and pedestrians are waiting in the central stopping area, vehicles must slow down and proceed cautiously, ensuring safety while allowing pedestrians to cross. Situations where U-turns are allowed: If there is a U-turn sign at the intersection, you can make a U-turn. If there is a U-turn traffic signal, you must follow the signal's instructions. If there is no signal, you can make a U-turn as long as it does not interfere with other vehicles or pedestrians. If there is no explicit prohibition of U-turns or left turns at the intersection, you can make a U-turn. "No explicit prohibition" means there are no signs like "No U-Turn," "No Left Turn," or solid centerlines, in which case you can safely make a U-turn. U-turns are also allowed in yellow grid zones. Yellow grid lines are no-parking zones marked at intersections or important entrances where temporary parking could cause congestion. Stopping on these lines (including waiting for traffic lights) is a violation. However, while parking is prohibited in yellow grid zones, U-turns are allowed as long as there is no central barrier, effectively making it a "U-turn permitted" zone. If there is a U-turn traffic signal at the intersection, you must follow the signal—only proceed on green. If there are both "No Left Turn" and "U-Turn Allowed" signs, U-turns are permitted but left turns are not. Note that "No U-Turn" is not the same as "No Left Turn." Things to note when making a U-turn at an intersection: Check the road markings. If they are solid lines, U-turns are prohibited under any circumstances. Continue driving to find a suitable location. If there is a "No Left Turn" sign, even if there is no explicit "No U-Turn" sign, U-turns are not allowed at that intersection because U-turns inherently involve a left turn. U-turns must be made from the innermost left-turn lane. If you are in the second left-turn lane, you cannot make a U-turn at that intersection. Always yield to oncoming traffic when making a U-turn. Proceed only if it does not interfere with their right of way, or you will bear full responsibility for any accidents. Near the intersection stop line, lanes usually have guiding arrows. The leftmost lane is not always a left-turn lane—if it has a straight arrow, U-turns are prohibited even if there are no explicit "No U-Turn" signs.

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Why Is There Abnormal Noise When Stepping on the Accelerator in a Car?

Abnormal noise when stepping on the accelerator in a car is usually caused by excessive gaps in components such as the drive shaft, poor lubrication, or improper assembly during repairs, resulting in friction-generated sounds when high torque is output. Abnormal noises can be divided into three categories: Abnormal noises (unusual sounds) can be classified based on their impact on vehicle performance as minor noises, moderate noises, and severe noises. Minor noises, such as sparking from high-voltage leakage or slight looseness in rolling bearings, are generally low in volume and do not significantly affect component wear over time. These issues can often be ignored while maintaining normal vehicle operation. Moderate noises, such as those from flywheel bearings or clutch release bearings, have a noticeable impact on vehicle performance but can still sustain key technical functions in the short term. These noises are usually louder and indicate greater component wear, requiring timely repairs. Accelerator Pedal Issues: When starting the engine, the engine oil temperature may not have reached its normal operating value, leading to viscosity unsuitable for the hydraulic lifter's optimal performance. Reduced sealing in the hydraulic lifter can produce noise. If accelerator pedal issues occur while driving a new car, remain calm. The only reasonable solution, as recommended by professionals, is to firmly press the brake pedal, bring the vehicle to a complete stop, turn off the engine, and then contact for assistance. When starting the engine, avoid fully depressing the accelerator pedal; slightly higher than idle throttle is preferable.

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What to Do When the Car Temperature is Too Low in Winter?

In winter, if the car temperature is too low, the engine coolant temperature should be adjusted. Here are some details about low car temperatures in winter: 1. Low Temperature: Excessively low temperatures can make it difficult to ignite the air-fuel mixture or cause delayed combustion, leading to reduced engine power. The engine oil may thicken due to the low temperature, increasing viscosity and resistance to moving parts. Additionally, unvaporized fuel can wash over the cylinder and piston. 2. Oil Dilution: During engine operation, a significant amount of heat is dissipated by the cooling medium. Therefore, maintaining the proper coolant temperature and minimizing unnecessary heat loss are crucial for improving fuel efficiency in vehicles.

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What do D1, D2, and D3 mean in an automatic transmission?

What are the three types of transmissions classified by operation method?

How to Claim Insurance for a Flooded Vehicle Without Water Damage Coverage?

Why does the noise persist after replacing the new belt when the air conditioning is turned on?

Do You Need to Wait for a Traffic Light When Making a U-Turn on a Dotted Line?

Why Is There Abnormal Noise When Stepping on the Accelerator in a Car?

What to Do When the Car Temperature is Too Low in Winter?

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