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How to Replace Serpentine Belt Tensioner 09-14 Ford F150

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How to Replace Serpentine Belt Tensioner 09-14 Ford F150

Created on: 2019-06-04

Learn how to replace the serpentine belt tensioner on your 09-14 Ford F150 EcoBoost with this 1A Auto instructional video.

  1. step 1 :Removing the Serpentine Belt Tensioner
    • Raise and support the vehicle
    • Twist and remove the four white twisting retainers on the underbody shield
    • Remove the rest of the plastic retaining pins securing the underbody shield
    • Remove the underbody shield
    • Turn the serpentine belt tensioner counter-clockwise with a 15 mm socket to release tension from the belt
    • Slip the belt off the tensioner pulley and release the tensioner
    • Remove the belt from the rest of the pulleys
    • Remove the two 10 mm bolts securing the serpentine belt tensioner
    • Remove the serpentine belt tensioner
  2. step 2 :Installing the Serpentine Belt Tensioner
    • Insert the serpentine belt tensioner into place with the bolt holes aligned
    • Replace and tighten the two 10 mm bolts
    • Place the serpentine belt over the water pump pulley, around the alternator pulley, and around the Crank pulley
    • Hold the slack of the belt towards the tensioner pulley
    • Turn the tensioner counter counter-clockwise with a 15 mm socket, and slip the belt over the pulley
    • Run the engine to check that the belts stay on their tracks
    • Shut off the engine, and feel to ensure the belts are aligned properly

Tools needed for replacement

  • General Tools

    Jack Stands

    Floor Jack

  • Ratchets & Related

    Socket Extensions


  • Sockets - Metric

    15mm Socket

    10mm Socket

  • Specialty Tools

    Plastic Fastener Remover

Installation Video
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Hey friends, it's Len here at 1A Auto. Today we're working on a 2011 Ford F-150 with the eco-boost. We're going to be replacing the serpentine belt tensioner. It's going to be a fairly easy job. I want to be the guy that shows you how to do it. So if you need any parts or instructional videos, you can always check us out at All right everybody, so where we're going to start is we're going to get underneath the vehicle, whether you're laying on the ground, or you're lucky enough to have it up on a lift like I am. There's a couple of these white clips right here. These are just little twists. So essentially you're just going to turn them a little to the left. All that does is unlock them. Then you can pull this down. Okay? We're going to use our little forkey tool. Now I'm just going to work my way around. Try to get all these little push clips out. If you want to leave a couple of them in to leave it hanging, it's up to you. It's your prerogative.

I'm just going to go ahead and get it right out of my way. The last thing I need is something hanging down in my face. There we are. We'll get this right out of the way. So one of our first steps is after we got this little splash shield out of the way. What we're going to do, turn on our light so we can see, just like that. I'm going to use a 15 millimeter socket on my ratchet. And I'm going to go right to the tensioner, right there. I'm going to try to turn that. I'm going to hopefully pull the tensioner so it loose ... Relieves, sorry. So it relieves tension on the belt so that way there I'll be able to remove the outer belt, which is the serpentine belt. So I'm going to turn it counterclockwise once I get it on, just like this. Now I'm going to try to get the belt off the crank. Now I can relieve pressure with the tensioner and my tool, get it right out of the way. So there isn't very many pulleys on this to try to remember.

But you're going to want to try to keep a mental picture of it in your head, the way that the belt goes. It's fairly simple. Goes around the water pump, comes back this way around the tensioner, around the crank, back up to the alternator and the background of the water pump. Easy peasy. Okay? So we'll grab that right out of the way, just like that. Now we've removed our serpentine belt. We're going to match this up. So we have our old belt and our new belt. What I'm going to do is I'm going to rest them both on my thumb, going to bring my hand down, and I'm going to put it on my other thumb. Then I'm going to try to stretch them. I want them to be about the same length. All right? If you've got one belt that comes maybe all the way out to here in comparison with your thumb, well you probably got the wrong belt. Okay? They did match up pretty good.

Next what we're going to do, we're going to compare the width, make sure that they're both the same width, which they are. Lastly, we're going to count the amount of ribs inside. This is where the pulley rides. You're going to have ribs on some of your pulleys. They're going to ride inside these ribs on your belt. So if you've got six ribs here and then seven ribs on your new belt, you got the wrong belt. This one looks fine. So we can go ahead and install this in a minute. So now I've got my 10 millimeter socket on a long extension with my three eighths ratchet. I'm going to go ahead and put it on the lower bolt. It's just a 10 millimeter head. Turn it to the left. I'm going to get it pretty loose, but I don't want to fully remove it. There we go. If I can get this up here. I'm going to need a shorter extension, of course. This lower one is a little more snug. I'm going to remove the bottom one first. There we are. I'm going to hold up the tensioner with my fingers.

Remove the upper one. The tensioner may fall down, so you're going to have to watch your face. There we go. Tensioner, pull that out. We've got our two bolts. So we're just going to match up our two parts. As you can tell, they both have two mounting holes. They look as though they would line up perfectly. You want to make sure that the pulley's the same. It is. If one was ribbed and one was flat, you'd have an issue. It looks about the same that way too. I'd say we can go ahead and mount this in. So here we go. Let's get this in. I'm just going to bring it over. I'm going to start with one bolt. I'm going to put it in the upper hole. Get it ready. Going to get my hand up in here. Try to line it up. All I'm going to do is start this one end and then I'm going to grab my other bolt and start that one end. I'm not going to go ahead and tighten either of them until both are started. So they're both started, now I'm just going to bottom them out.

And then we'll snug them up, with my socket with a 10 millimeter, or a 10 millimeter socket I mean. Feels pretty tight. Grab this one. Bottomed it out. Give it a little more. I'm just going to double check the top one. Feels good. All right. Now we're clear to put our socket on here, and we're going to move the tensioner. Once we get the belts all lined up, we'll bring that down and we'll get the belt on. Okay, so we're going to take our serpentine belt. We remember we're going to go over the water pump, across over the alternator, under the crank, up and over, around this, and then back up over the water pump. So let's give it a try. I'm going to put the belt over the water pump first. There we are. Over the alternator. So this is pretty much how it's going to want to go, right? Of course it's going to be sitting in the grooves a little better. We'll just take it off that tensioner for now. We'll get it around our crank, around our water pump, get everything kind of situated where it's going to need to go.

That looks pretty great. I'm going to grab my 15 millimeter socket on my ratchet again. I'm going to make it so it's going the right way. You need to turn this to the left. That's going to relieve tension on the tensioner. Give us room to get the belt on. I'm going to regroup here. Okay. That slid on. I'm just going to take a peek at all the belt, looks pretty good, relieve tension. Now I'm going to just run my fingers along where the belt meets into the grooves. Make sure it's not sticking up anywhere. It's not off a tooth. Sometimes you might get your belt on and it might come off the side of the crank a little bit, either to the front or to the back, or even one of the other pulleys. So you just want to make sure it's not coming off. It's sitting in all the grooves. That feels pretty great. Thing's nice and snug. There we go.

Now what we do is we just start it up, let it run for a couple seconds, turn it right off, and then double check to make sure everything stayed where it's supposed to be. Okay? I'm just going to try starting it up real quick. I'm going to let it run for maybe five, 10 seconds. Take the key back out. Now we're just going to make sure the belt is still in its tracks. So the key's out of the ignition, it's not running. I'm going to check it. Feels like it's definitely in the track there. Top side of the crank feels great. Bottom side of the water pump. It's perfect. Double check the AC belt where it runs inside the air conditioning pulley, feels great. Let's see if I can come over here where it runs inside the crank. It's perfect. All right, there we go. Great job. So here we go. We're going to go ahead and install this back up under here. It's just got a couple of push clips going around. So we're going to find the holes we took them out of.

We've got one right here, one right there, and then we're going to go basically just follow wherever they line up with. Okay? So I'll get these two. And now as Johnny Cash says, I'll walk the line. And go like this. Like that. I love that guy, by the way. Easy peasy. All right everybody, that's locked in.

Thanks for watching. Visit for quality auto parts shipped to your door, the place for DIY auto repair. And if you enjoyed this video, please click the subscribe button.

Tools needed for replacement:

    General Tools

  • Jack Stands
  • Floor Jack

  • Ratchets & Related

  • Socket Extensions
  • Ratchet

  • Sockets - Metric

  • 15mm Socket
  • 10mm Socket

  • Specialty Tools

  • Plastic Fastener Remover

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