Should You Flush It, Change It, Or Leave Transmission Fluid Alone?

If you're trying to do a lot of car maintenance yourself, one of the tasks that might be stopping you involves the transmission fluid. Whether or not to change or flush the transmission fluid is actually the subject of a lot of debate -- it's not as cut and dried as changing coolant or changing the oil. Here's a look at the three options and why you may or may not want to do them.

Leaving It Alone

In a nutshell, you should change the transmission fluid eventually. However, you don't have to change it for the heck of it. If it looks clean and doesn't look like it's started to darken, as can happen with old transmission fluid, you may be able to wait. Each manufacturer has its own recommendations for when you have to change the fluid for a particular model, but those recommendations aren't set in stone if the fluid looks good and the level is good. Of course, the manufacturer set those recommendations for a reason, and chances are as you approach the supposed mileage limit for your transmission fluid, the fluid will start to look bad.

Changing the Fluid

As mentioned, the looks of the fluid play a large role in whether you can wait or if you have to change the fluid. Another time when you may want to be proactive in changing the fluid is if you do a lot of stressful driving -- the stop-and-go of dense traffic, several long-distance drives in a short time, and so on. If you're really pushing your engine, then jumping the gun a bit and changing the fluid at the recommended intervals, even if the fluid looks good, is a good idea.

Flushing It

Flushing the fluid is different than changing it. When you flush fluid -- and this is something that a transmission specialist should do, rather than you trying to do it yourself -- you use special equipment to force all of the old fluid out. It's essentially a way of cleaning the transmission, if you want to view it that way. There is controversy about this; the power behind the flushing could potentially damage the system if not done carefully. On the other hand, flushing out gunk can be beneficial because that gunk is no longer in the system and potentially causing restrictions for fluid flow.

If you're still not sure if you should change the fluid, or if you want to try bringing it in for a flush, talk to a transmission specialist like McCarty's Transmision Service Inc. who can evaluate your particular car.