Here's a breakdown of potential issues:
Potential Problems:
* Dislodging debris: After 200,000 miles, the transmission fluid is likely quite dirty and contains sludge and worn particles. Flushing the transmission (a more aggressive fluid change) can dislodge this debris and potentially clog the transmission's filter or valves. This could lead to transmission failure. A simple drain and fill (replacing only a portion of the fluid) is less likely to cause this problem.
* Seals and gaskets: Old seals and gaskets may have hardened and become brittle over time. The new fluid might penetrate these weakened areas and cause leaks.
* Worn internal components: The transmission itself might be so worn that new fluid only highlights the existing problems. The fluid might temporarily improve performance, giving a false sense of security before the transmission ultimately fails.
Potential Benefits:
* Improved shifting: Dirty fluid contributes to harsh shifting and slipping. New fluid can significantly improve smoothness and responsiveness.
* Extended transmission life: Clean fluid helps lubricate and cool the transmission components, reducing wear and tear.
* Reduced wear on other components: Smooth shifting reduces stress on the engine, clutch, and other drivetrain components.
Conclusion:
The biggest risk lies in the condition of the transmission itself. If it's already showing significant signs of wear (slipping, hard shifting, unusual noises), changing the fluid might only temporarily mask the underlying issue and delay a necessary, more expensive repair. On the other hand, if the transmission is functioning relatively well, a simple drain and fill is often a worthwhile preventative maintenance step.
Recommendation:
Before changing the transmission fluid in a high-mileage car, it's best to:
* Have a professional inspect the transmission: A mechanic can assess its condition and advise whether a fluid change is advisable.
* Opt for a drain and fill rather than a complete flush: This minimizes the risk of dislodging debris.
* Use the correct type and amount of transmission fluid: Using the wrong fluid can damage the transmission.
Ultimately, the decision of whether or not to change the transmission fluid at 200,000 miles is a calculated risk based on the condition of the transmission and your comfort level with potential problems. A consultation with a trusted mechanic is highly recommended.
