A welded differential is a process whereby the gears (usually spider gears) inside the differential are welded so that the differential no longer allows the wheels on either side to rotate at different speeds. With this modification, the wheels on either side of the axle are permanently locked, forcing them to rotate at the same speed in all circumstances, thus eliminating the differential effect when turning.
How a standard differential works?
In a normal open differential, the differential allows the two wheels on the same axle to rotate at different speeds, which is critical when the vehicle is turning. When a car turns, the outside wheel needs to rotate faster than the inside wheel because the outside wheel has a longer distance to travel, and the differential makes the speed difference between the wheels possible, allowing the vehicle to pass through the corner smoothly.
How a welded differential works?
A welded differential forces the two wheels on the same axle to always rotate at the same speed by welding the gears inside the differential. It locks the axle, preventing the speed difference between the wheels under normal circumstances. This modification is common in drift racing because it ensures that the rear wheels always get the same traction, making the vehicle easier to control and keep sliding during drifting.
Advantages of welded differentials
- Maximum traction: Since the wheels on both sides always rotate at the same speed, the vehicle can obtain more stable traction and reduce the risk of loss of control when racing or off-road driving.
- Drifting use: In drift competitions, welded differentials help lock the rear wheels, making it easier for the vehicle to enter and maintain a drift state, providing more predictable oversteer (swinging).
- Lower cost: Compared with purchasing a limited slip differential (LSD) or a locking differential, welded differentials are a more economical modification.
Disadvantages of welded differentials
- Difficult to turn: Since the wheels cannot rotate independently, the vehicle is prone to “tire drag” when turning at low speeds, and driving control becomes stiff and laborious, especially when parking or driving in the city.
- Increased tire wear: The wheels cannot rotate at different speeds according to the turning requirements, resulting in accelerated tire wear on dry roads, especially the wear of the inner tires will be more serious.
- Decreased driving comfort: The welded differential makes the vehicle bumpy when turning, and it will feel more stiff during driving, especially in daily driving, and the ride comfort in the car will be significantly reduced.
- Increased danger on slippery roads: On rainy, icy, or muddy roads, welded differentials make it easier for the rear wheels to lose grip, causing the vehicle to drift or lose control, increasing driving risks.
- Suspension system is under greater pressure: Since the wheels cannot rotate independently, welded differentials impose greater stress on the suspension and transmission system, causing these components to wear or damage prematurely.
Conclusion
Although welded differentials can provide better traction and control in specific uses such as drifting or off-roading, they have many disadvantages for daily driving. These include inconvenient cornering, rapid tire wear, and safety hazards on slippery roads. Welded differentials are more suitable for specific racing scenarios and are not suitable as differentials for daily use. If the main purpose is daily driving, a limited slip differential (LSD) or other types of differentials may be a more appropriate choice.
