Using power steering fluid in place of transmission fluid is not recommended, as it can lead to poor transmission performance and eventual failure. Here’s an overview of why power steering fluid and transmission fluid are not interchangeable:
Different Fluid Properties
Power steering fluid and transmission fluid are designed with different properties and additives:
- Transmission fluid is slippery with high detergent levels to allow smooth gear shifts and lubricate components. It also has anti-wear additives and viscosity improvers.
- Power steering fluid has less detergent and friction modifiers to allow the power steering pump to operate with little resistance. It is also less viscous.
Incompatible Additives
The additives in power steering fluid can interact negatively with those in transmission fluid formulations:
- Detergents may break down transmission fluid anti-wear additives over time.
- Friction modifiers can make transmission operation noisy and lead to slipping.
- Contaminants can clog small valves and orifices in the transmission.
Reduced Lubrication
Power steering fluid has a lower viscosity and lacks the viscosity improvers in transmission fluid. This can lead to:
- Premature wear as parts are not sufficiently lubricated during operation.
- Leaks as seals are not maintained properly.
- Overheating and damage due to increased friction.
Transmission Failure
Using power steering fluid long-term can ultimately result in complete transmission failure requiring a rebuild or replacement. Signs of damage include slipping, erratic shifting, and abnormal noises.
In summary, always use the manufacturer’s recommended transmission fluid. Power steering fluid lacks the specific properties required for proper lubrication and friction control. Mixing the two fluids or using the wrong one will likely lead to transmission damage and costly repairs.
Frequently Asked Questions
What if I already put power steering fluid in my transmission?
Have your transmission drained and refilled with the proper fluid as soon as possible to reduce potential damage.
What are symptoms of transmission damage from wrong fluid?
Watch for slipping, delayed/hard shifting, grinding noises, fluid leaks, or overheating which may indicate damage.
Can I mix power steering and transmission fluid as an emergency fix?
No, any amount of power steering fluid in the transmission can start to cause damage over time. Only use the correct fluid.
How often should transmission fluid be changed?
Follow your owner’s manual, but typically every 30,000-60,000 miles is recommended to refresh additives.