Bucking or Hard Shifts Learn Transmission Symptoms on Your Car or Truck

We have this GMC Acadia with a transmission issue. Let's get into it.

If you enjoy this video, make sure you subscribe to our channel, ring that bell and turn on all notifications so you don't miss any of our videos. With the engine running and it up to operating temperature, we want to check the transmission fluid level. The dipstick is right here, it's where the fill cap is. So, I will just take that out, you want to check it, wipe it off. You can tell a lot by the fluid, one by the color of the fluid and then also by the smell of the fluid. So, wipe it off, put it back in, pull it out again and see if it's within those hash marks. So, if the fluid smells burnt then that's an indication that something has burned up in the transmission and you're going to need to pull the transmission out and see what went wrong. Just draining and filling the fluid isn't going to fix your problem. There's obviously a major internal failed component.

So, top off the fluid, put the cap back on. All right. So, what we want to do now is we want to go out and drive the vehicle, see how it feels, make sure it's nice and warm and see if it shifts a little weird at slow acceleration, medium acceleration, and fast acceleration. We do feel a little bit of a bump around third gear and that might be normal. We'll drive it around a little bit more just to see what we see and see how it downshifts as well. If it downshifts funny, if something feels weird, then might be something to look into.

All right. There's first gear. Here's the second gear, that felt pretty good. Wow, that was third gear. That didn't feel so good. Fourth gear, fourth gear's smooth and we're going to have to try to accelerate getting on the highway to get to fifth and sixth gear. All right. So, when we're cruising on the highway, cruising speed's around 60 miles an hour. And we come to a slight incline. If we can just accelerate slightly while you're going up the hill and you hear like a vibration or you feel a heavy-duty, like almost like a droning sound, you can hear it, that's the torque converter clutch slipping and at that time you're going to need a torque converter.

So, these are the codes that we have in this vehicle and there's a transmission fluid pressure code. Now, what's probably going on in this is the TCM actually has little diaphragms over the pressure sensors. Those diaphragms end up ripping and then coming out. So, those have to be replaced. You can't replace just the diaphragm, you have to replace the whole TCM. Which based on the mileage on this vehicle, it's got 118,000 miles and the fact that when we were driving it third gear felt a little funny, there was a little bit of a hiccup in there. The transmission is going to have to come out. There's no way to replace the transmission filter unless you pull it out and split the case half-open. So, at this point, that's gotta come out. We're going to have to replace that TCM and see what else is going on.

Thanks for watching. Visit 1aauto.com, your place for DIY auto repairs, for great parts, great service, and more content.