Oxidation is what wears out transmission fluid and oxidation is caused by heat. If the transmission fluid temperature never exceeded 170 degrees, it could in theory last 100,000 miles but if the temperature routinely exceeds this by 20 degrees, the oxidation rate doubles.

So at 190 degrees the replacement mileage would be 50,000 miles. But when towing a trailer through the mountains transmission temperatures can reach 210 to 260 degrees. If this type of towing was routine, the fluid change interval would be 12,000 miles. Stop and go driving also increases the temperature of the fluid. 

If you had to rock your vehicle out of the snow numerous times the fluid may be oxidized.

Oxidized fluid no longer lubricates the transmission sufficiently and will cause excessive wear.

How And When To Change Fluid

An automatic transmission oil change involves removing the oil pan, draining the fluid, replacing the gasket and topping up the fluid. This usually replaces only 4-5 quarts out of 12-13 total quarts total in the transmission. If the transmission fluid is oxidized, after a drain and fill it would still be 2/3 oxidized. A more thorough method is to flush the fluid in the transmission. New fluid is pumped into the transmission while the old fluid is pumped out resulting in 100% fresh transmission fluid.

Depending on the vehicle and driving conditions, 30,000 to 60,000 miles should be the interval for replacing the transmission fluid.

Keeping your transmission in good condition is part of the service we offer.

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