When automatic transmission fluid becomes old or contaminated, it can lose its lubricating and cooling properties, leading to increased wear and tear on transmission components and potentially causing damage. Flushing and changing the fluid helps remove harmful contaminants and restore the fluid's performance, which can extend the lifespan of the transmission.
That being said, it is important to follow the recommended maintenance schedule provided by the manufacturer, which may not necessitate a transmission fluid change at 135,000 miles. If you are unsure about whether a transmission fluid change is necessary, it's best to consult with a qualified automotive technician.
