Transmission fluid, like motor oil, helps lubricate and cool its moving parts so your engine can smoothly transfer power to the wheels on the road. 

And like motor oil, transmission fluid will need to be replaced since it deteriorates over time. How often to replace transmission fluid will depend on the transmission type as well as how strenuously the vehicle is driven. Generally, manual transmission vehicles need new transmission fluid every 30 – 60,000 miles while automatic transmissions can usually go 60 – 100,000 miles before changing fluid.
    

CAN YOU CHANGE TRANSMISSION FLUID AT HOME?

While it’s possible to save money and change transmission fluid yourself at home, it makes more sense for most vehicle owners to let your trusted AAA mechanic do it. Most transmission systems don't have a drain plug, but instead feature a pan where fluid collects. 

This means you must remove the pan entirely to drain the fluid and change the gasket and filter. This process can be extremely messy. It requires properly cleaning all surfaces to install the new gasket, and you’ll need a new transmission fluid filter, too. 

Without the proper tools and catch equipment in place, changing transmission fluid yourself can be more trouble than it's worth. Plus, if you don't change the gasket properly, you could end up with a transmission fluid leak that sets you back even more money and time. 

Depending on the make and model of your vehicle as well as transmission type (manual or automatic), transmission fluid can be changed for $80 – $250 in most areas.
   

KNOWING WHEN TO REPLACE TRANSMISSION FLUID

• Noisy Transmission: When you're driving your vehicle, if you notice noisy shifting, particularly from lower to higher gears, this can be an indicator of worn-out transmission fluid.
• Rough Shifting: Similar to a noisy transmission, a transmission that shifts roughly or with sudden jerks often needs to be inspected and have its fluid replaced.
• Slipping Transmission: If you feel like your transmission is taking longer to engage than normal or it slips out of gear, your fluid may either be bad or running low. You should check for leaks and see a professional for advice.
• Engine Doesn't Engage: If you can't get your vehicle to engage in drive or reverse gears, your transmission fluid may be the culprit, but there also could be larger issues at play.
• Dark or Leaking Fluid: If you notice puddles of fluid under your vehicle that are either red or dark brown, this can be an indicator of a fluid leak and should be addressed immediately. Similarly, if you check your fluid and it appears dark brown, black or smells burnt, this can also be an indication of transmission problems. In both cases, you should see a professional for help immediately.