automobile suspension, car control arms, auto shock absorber, Independent suspension, auto semi-independent suspension, non-independent suspension, McPherson suspension, rigid beam, torsion beam

What is the automobile suspension system?

The suspension system is located between the wheels and the vehicle body, with the wheels connected at the bottom and the vehicle body connected at the top, playing the role of connecting the upper and lower parts and absorbing shock and buffering. The suspension system between the wheels and the vehicle body will automatically compress and straighten to help buffer and prevent rebound, so that the vehicle body can be kept as horizontal as possible, which can greatly improve driving comfort. Common suspension systems on the market are divided into independent suspension, non-independent suspension and semi-independent suspension. The left and right wheels are installed on the same rigid crossbeam, forming a whole. When the right wheel encounters an obstacle and jumps, the left wheel will also jump. This is a non-independent suspension. This type of suspension is simple, reliable and low in cost, but because the two wheels are fixed together, when one wheel is impacted by the road surface, the other wheel will also be affected, so the comfort of the non-independent suspension is poor. It is now mainly used in trucks, buses and some SUV models.

Independent suspension, the two wheels are connected to the body through movable control arms, they can move independently without interfering with each other, so when one wheel is impacted and bounced by the road, it will not affect the other wheel, so the stability of the independent suspension system will be better, and it can absorb the vibration and impact of the road, so its driving comfort will be higher, and at the same time, because the independent suspension system removes the middle rigid axle, it frees up more space, so its cabin space will be larger. At present, the McPherson suspension system is widely used on the market.

The semi-independent suspension system improves the middle rigid beam on the basis of the non-independent suspension system, so that the original rigid beam becomes a torsion beam with a certain elasticity. The torsion beam can withstand a certain degree of deformation. When the right wheel is impacted and bounced, part of the impact force will be consumed by the deformation of the torsion beam, so the left wheel will be affected less, which plays a role in lateral stability. This semi-independent suspension system is what we often call the torsion beam suspension system. Its stability and comfort are generally used in the rear suspension of mid-range cars.

AT transmission shift automatically, car transmission control module, speed change mechanism, auto transmission clutch, planetary gear, auto transmission valve body

How Automatic Transmissions Shift Gears: Principles & Maintenance Guide

1. What is an AT Automatic Transmission?

An AT (Automatic Transmission) allows drivers to shift gears without manually operating the clutch. Through intelligent control and mechanical execution components, it adjusts power output for smooth and effortless driving.

2. Two Key Roles in Gear Shifting

AT gear shifting can be understood as a collaboration between two roles:

2.1 Transmission Control Module (TCM) – “The Brain”
Collects vehicle speed, engine RPM, throttle position, and brake status
Determines driver intention
Decides when to upshift or downshift

2.2 Execution Mechanism – “Hands & Feet”
Planetary gearsets and multi-plate clutches
Perform gear changes according to TCM commands

3. Gear Shift Decision Process

The TCM works as follows:
Data Collection: Vehicle speed, engine RPM, throttle, brake status
Driver Intention Analysis: Accelerate, decelerate, or cruise
Gear Selection: Based on driving mode (Economy/Sport) and shift logic
Command Execution: Hydraulic or electronic signals control the clutch to complete gear changes
Tip: Shift smoothness and responsiveness depend on TCM calibration.

4. Execution Components: Planetary Gearsets & Multi-Plate Clutches

Planetary Gearsets: Sun gear, planet gears, and ring gear combination that changes power output ratios
Multi-Plate Clutches: Controlled hydraulically or electronically, engage or release gear combinations to shift gears.

5. Common AT Usage & Maintenance Tips

Avoid frequent hard acceleration or sudden braking
Replace transmission fluid regularly
Pay attention to warning lights and address electronic issues promptly
Use appropriate driving modes (Economy/Sport/Manual) according to conditions

6. FAQ – Frequently Asked Questions

Q1: Is it normal for the AT to jerk slightly during shifts?
A: Minor jerks can occur due to hydraulic or gear temperature changes. Persistent or strong jerks should prompt checking transmission fluid and clutch condition.

Q2: Can automatic transmissions operate in manual mode?
A: Many models support manual mode using paddle shifters or gear lever. The TCM still protects the engine and transmission.

Q3: How can I extend the life of my AT transmission?
A: Maintain smooth driving habits, perform regular maintenance, replace transmission fluid, and avoid excessive coasting or high-load starts.

7. Conclusion

The AT automatic transmission is the result of intelligent control + precise execution:
TCM (Brain): Analyzes driver intention and decides when to shift
Planetary Gearset & Clutch (Hands & Feet): Execute gear changes
Understanding its operation not only improves driving comfort but also helps prolong transmission life.

 

Why do we need Brake Pad Wear Sensor?

1. Improved safety: By monitoring the wear degree of the brake pad in real time, the Brake Pad Wear Sensor can ensure that enough braking force is provided at critical moments, thus improving the safety of driving.
2. Prevent accidents: If the driver fails to detect the condition of the brake pad is too thin in time, it may lead to the loss of control of the vehicle or the increase of braking distance, and then cause traffic accidents. With the warning function of the Brake Pad Wear Sensor, this kind of risk can be greatly reduced.
3. Extended service life of the brake system: timely replacement of the brake pad not only ensures the safety of driving, but also helps to extend the overall service life of the brake system and save maintenance costs.

What is the Brake Pad Wear Sensor?

The Pad Wear Sensor is a device used to monitor the wear degree of brake pads. When the thickness of the brake pad is lower than a preset value, the sensor will send a signal to the vehicle’s electronic control system to remind the driver to replace the brake pad in time, so as to avoid the safety hazards caused.