The Importance of Using Standard Transmission Fluid
Having standard transmission fluid in your vehicle’s gearbox, especially in automatic and manual models, is extremely important. This fluid helps prevent wear on the internal gearbox components and stops it from overheating. As a result, the gearbox operates optimally and its lifespan is extended. Therefore, paying attention to transmission fluid leaks is essential because this issue can lead to costly repairs and maintenance of the gearbox in the future. One key point in this regard is understanding the causes of transmission fluid leaks. In this article, we examine the reasons behind transmission fluid leaks in both automatic and manual gearboxes.
Causes of Transmission Fluid Leaks
Transmission fluid leaks, whether in manual or automatic gearboxes, can occur due to various reasons. Some of the most important causes include:
- Damage to the transmission oil pan gasket
- Puncture or hole in the transmission oil pan
- Faulty transmission drain plug
- Wear and tear of the transmission fluid lines
- Excessive overheating of the transmission
- Damage to the torque converter in automatic transmissions
- Malfunctioning of the automatic transmission solenoid valve
Here is a detailed explanation of each cause:
Damage to the Transmission Oil Pan Gasket
The transmission oil pan is a chamber where the transmission fluid is stored after circulating through the transmission system to cool down. To prevent fluid leaks, a gasket is installed at the oil pan opening, secured with special bolts to the transmission housing. If this gasket becomes damaged due to impact, wear, or excessive heat, transmission fluid will start leaking from this area. The solution is to replace the oil pan gasket.
Puncture or Hole in the Transmission Oil Pan
The oil pan is located at the lowest point of the transmission and is exposed to impacts. Therefore, it is susceptible to damage especially from collisions or road obstacles. Such damage can cause cracks or holes in the oil pan, resulting in rapid transmission fluid loss.
Faulty Transmission Drain Plug
The drain plug is located under the transmission oil pan and is used for draining and replacing transmission fluid. This plug screws in and out via threads. If the drain plug is damaged by impact or wear, it may not seal properly, causing transmission fluid to leak through the gaps.
Other Causes of Transmission Fluid Leaks
Wear of Transmission Fluid Lines:
The transmission fluid lines are also susceptible to damage and wear. If these lines get damaged, fluid will leak from them, potentially causing a drop in transmission fluid levels.
Excessive Transmission Overheating:
Transmissions exposed to high heat are more likely to leak fluid. Excessive temperature can damage gaskets and internal components, leading to leaks.
Damage to Torque Converter and Solenoid Valve in Automatic Transmissions:
In automatic transmissions, faults in the torque converter or solenoid valve can also cause fluid leaks. These issues typically require specialized repairs.
By understanding these causes and carefully inspecting the transmission, larger problems and extra costs can be effectively prevented.
Wear of Transmission Fluid Lines
A common cause of transmission fluid leaks in vehicles like the Pride and other models is cracks or damage to the transmission fluid lines. These lines are usually made of metal and carry transmission fluid to different systems such as the cooling system. In vehicles where the oil cooler is outside the transmission housing, a metal line guides the fluid to this system. Wear or damage to these lines can cause leaks. To diagnose this issue, inspect the transmission fluid lines carefully; the presence of grease or fluid on the lines indicates a leak that requires further investigation.
Excessive Transmission Overheating
Another significant cause of fluid leakage in transmissions such as those in Samand EF7 and similar cars is overheating. Over time, transmission fluid loses its properties and can no longer protect internal parts properly. This increases the risk of overheating, which may cause leaks. Often, excessive overheating triggers the transmission warning light (“Check Transmission”) on the dashboard, indicating the need to inspect and replace the transmission fluid.
Damage to the Torque Converter in Automatic Transmissions
The torque converter is a vital component in automatic transmissions, responsible for transferring power between the engine and the gearbox. It consists of three main parts: the pump, turbine, and stator, with hydraulic fluid circulating inside to assist in torque transfer. Sometimes, a failure in the transmission pump seal can cause fluid leaks. However, even after replacing the seal, leaks may persist. In such cases, damage to the pump or turbine could be the root cause of the leak and requires a thorough inspection.
Failure of the Solenoid Valve in Automatic Transmissions
The solenoid valve in automatic transmissions plays a crucial role in regulating and controlling the flow of transmission fluid. It is responsible for opening and closing the fluid flow within the system. If the solenoid valve malfunctions, it may cause transmission fluid leaks. If you suspect solenoid valve failure, you should also check the transmission fluid level. If the fluid is low, besides replacing the solenoid valve, the transmission fluid should also be changed to prevent further damage to the system.
In Conclusion
This article reviewed the causes of transmission fluid leaks in both automatic and manual gearboxes. It is also important to recognize the signs of fluid leaks. Besides spotting oil stains under the vehicle, pay attention to symptoms such as burning smells, vibrations during driving, unusual noises especially during gear changes, and warning lights on the dashboard in automatic vehicles. Remember, low transmission fluid levels can cause severe damage to the system, so take this issue seriously and address it promptly.