How to Drain and Fill Transmission Fluid 2007-16 GMC Acadia

Hi, I'm Mike from 1A Auto. We've been selling auto parts for over 30 years!

What's up, guys? I'm Andy from 1A Auto. In this video, I'm going to show you how to drain and fill a transmission. We've got this 2012 GMC Acadia with about a hundred thousand miles on it. This is the old fluid, it's nice and dark. This is what the fluid should look like, so we're going to try to make it look better. If you need any parts for your vehicle, click the link in the description and head over to 1aauto.com.

Under the hood here, we're going to take the transmission fill cap off. I don't want to get any dirt in the transmission. Twist it to the left and then pull it out. It's got the dipstick attached to it. On the cap it says what kind of fluid to use, at least for this vehicle. It's always a good idea to check your owner's manual as well.

Now, we're going to raise and support the vehicle. We're using a two-post lift. If you're doing this at your house, you can use a jack and jack stands. With the vehicle raised up, I'm going to make sure that we have a pan to catch the fluid, and then I'm going to take this drain plug out. I'm going to use a 11 mm socket and ratchet. Just take this out. Once it's kind of loose I'll use my fingers. I'm going to let this all drain.

Some things you want to look at when you're looking at the fluid, see the color of the fluid. This is obviously pretty dark. You're going to want to smell the fluid. If the fluid smells really bad, then there could be internal damage in the transmission. If there's a lot of metal in the fluid, it's another indication or clutch material, then there's probably internal damage.

When doing this, we're going to get most of the fluid out or a good portion of the fluid. We're going to drain it out and then fill it up, then we're going to drive it around for a while and then come in and repeat the process. We don't have a flush machine. Ideally, it would be better to flush the fluid out, but we're just going to do what we can with draining and filling.

All right, so now that that has drained out, I'm going to mount, so we're just going to put the plug back in. I'll use my socket, 11 mm socket and ratchet, just snug this up. Once it starts getting tight, just tighten it a little bit more. You're not going to tighten it all the way down to flush with the transmission, which just keeps getting tighter. That's good right there.

Now, we're going to take a nice long funnel like this and we'll just put that in the fill for the transmission fluid and we'll start putting the appropriate fluid in. It's nice and clean. When you're trying to figure out how much fluid you should put in, what you can do is take the fluid that you drained out and measure how much you drained out and then put that exact amount back in. You're also going to want to check it and make sure that it's good. This total transmission takes around nine quarts. That's completely dry.

The reason why we're going to do this multiple times is because draining this fluid out, we're only getting about four quarts, so that's a little less than half of the transmission fluid that's in there. A lot of the transmission fluid is stuck in the torque converter and that's not going to drain out just by draining it. What we'll do is we'll drain the fluid. We're going to drive it after we filled it up, then we're going to come back and drain it again and then refill it up. That'll get most of the old fluid out so that the transmission's at least in good condition, the fluid's in good condition. It'd be better, like I said before, it would be better if we flushed it, but we don't have a flush machine, so this'll be good.

All right, now I'm going to pull the funnel out. Just take a rag so I don't drip it. Put the dipsticks in and fill cap back on. Tighten it down. All right, we want to check the fluid level before we take it out for a ride. Remember that the vehicle's going to be cold when we check this, so it's not exactly accurate. I'm going to start the vehicle. Let it stabilize for a second. Put my foot on the brake and I'm going to shift through the gears. Put in reverse, neutral, drive, low, reverse, and then back to park, and then I'm going to go out and check the fluid level as it sits now.

Now with the engine running, keep in mind the engine's still cold, so it's not going to be up to where it needs to be. I'll reinsert the dipstick after I've wiped it off and then pull it out again. With the vehicle cold, the fluid's really going to be pretty low. It's going to be down here. We just want to make sure there's at least fluid on the dipstick. Now, the correct way to check this fluid level, you're going to want to have the engine hot. The engine's going to be driving for about 10 to 15 minutes, then you want to check the fluid on a level service in park while the engine's running, and it should be in between those hash marks right there. Right now it's cold, so that's why it's down here. Just going to add about half a quart. Now, I'll take the funnel out and install the dipstick and we'll go take this car for a ride.

We drove it around for a little bit after adding our fluid and we're going to drain it again and see what comes out. Already I can tell that the fluid looks a little better than it was. We took some samples here. This is what we started with, this was after draining and filling it one time. It's obviously a little bit better. You can see some red in the fluid, but it's still very dark. That's because of like I talked about earlier how the torque converter has some of the fluid in it and you can't drain it all out with the drain plug. After doing that and going one more time, driving it and filling it up, you're able to get the fluid to look like this, which is significantly better. It's not quite as good as brand new fluid, but again, with your transmission it's never going to look crystal clear.

This is what draining and filling multiple times would do. It's better than nothing. It's not quite as good as flushing the transmission, but this is what we can do on our own without a flush machine.

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