Time: 30-45min

Difficulty: easy-moderate

Cost: $60-150 (fluid type and capacity)

FUNCTION

An automatic transmission is a complex hydraulic pump with gears, clutches, bearings, valves, and actuators. The fluid in an automatic transmission is used to apply pressure, transfer torque, clean, cool, lubricate, and activate components. To perform its function, it needs to be in peak condition.

WHY SERVICE

Replacing the fluid often can prevent one of the costliest repairs you can experience on a vehicle, the transmission. Heat, shearing forces, contaminates, and time cause automatic transmission fluid to lose its protective properties. As the fluid additives and properties break down, temperatures increase, clutches wear, flow restricts, and components fail.

INTERVAL

GM recommends replacing the transmission fluid at 50,000 miles. Industry standard is anywhere from 30-60,000 miles, depending on driving conditions.  Heavy start/stop traffic, hills, towing, extreme temperatures, etc. warrant the earlier side of the range, while long-distance flat driving would warrant the latter.

What does on-condition mean? New fluid is pink/red and opaque. Spent fluid is brown to black and has a horrible burnt smell. You obviously want to replace it before it gets to that point.

METHOD

To completely exchange the transmission fluid, you'll need to tap into the flow circuit at the appropriate place. The best place is where the fluid leaves the oil cooler and returns to the transmission.

Watch the video below to see the complete transmission fluid exchange/flush on a 2011 Chevy Silverado 1500 with the 6-speed.