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​Transcript:

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Hey everyone, and welcome back to the channel. Today, we're taking a look at this Cub Cadet Ultima ZT1. A customer brought it in with a drive belt that is off, and it's got a crack down it. So we're gonna replace the drive belt on it, and we're also gonna replace the idler pulley since it's making some noise.

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I see this quite a bit on this model—where the belts pop off prematurely, and with not many hours on them. I'm gonna show you how to fix that so it doesn't continue to happen down the line on this model. Don't forget to hit that like and subscribe button as we go along if you enjoy the content.

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First thing I like to do is drop the deck down. You’ll hit the brake and then rotate it to the lowest setting, which is one—or right past one. That'll allow you to drop that deck all the way down.

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If your drive is not working on this model, one of two things has happened: either the belt has broken or come off, or your engagement here is disengaged. I've got it in the disengaged position right now—that's so we could push it in here. But in order to drive it, you can pull this and leave it down in that lever, and that’s where it should be during normal operation. There’s one on that side and also one on the other side.

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If you come right underneath and back, you can see very clearly that the drive belt is off. That’s not to be confused with the bottom belt—which is the deck belt. I'm actually gonna reinstall this real quick just to show you how it should be and the exact process if it’s still intact but in bad condition.

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At the front side, we have a pretty good view from where the deck is—all the belts, and then also the spring and how it should be installed, and where it is installed.

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The first step, if your belt’s still on, is gonna be to remove this spring from the notch here. I’ve got a spring puller, which makes it extremely easy. If you don’t have one, here’s one I made in a pinch. All you do is cut where the round hole is out of really any wrench that you can grip onto decently. This one worked very well when I needed it for that job.

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Either with that or the spring puller, we’re just gonna pull and let it drop off. That’s about how it was when I found it—just hanging there.

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Next, we want to get the clip removed from the PTO clutch. This wire is normally in this position, so you’ve gotta pinch the backside and pull that out. Otherwise, you can undo the clip to get the wire out and basically just pry between here to undo the clip on the wire. But really, that can stay in that position anyway—if it’s in your way, you can get it out. You just pull up on this and pull the whole connector out.

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So I’m just prying up on that tab a little bit to get it off where it’s locked—and that’s free.

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Then we’ll take and roll this belt off. It’s very easy if you just kinda grab down. Make sure not to pinch your fingers, but it’ll roll right off. Don’t let it snap back so it gets off some of the pulleys in the front. Just kinda set it right there.

There’s a bracket that holds the clutch from spinning here, and it’s gonna need to come off so we can get this belt off of that shaft. It’s just a ½-inch head to it. This bracket just comes off like such. It does have a little clip there that absorbs some of that movement back and forth.

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Now that it’s out of the way, with that screw/bolt out of the way, the belt can come off—after we get the idler pulley bolt loosened here.

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This idler pulley has a bracket that keeps the belt on the backside. This one was actually off of that—it had worked its way out. And when they come off there, that’s normally what ruins the belt.

Gonna use a 9/16", and then a wrench up top because there is a bolt that goes all the way through. We’re gonna completely remove it. But if you are just replacing the belt and not the idler pulley, you don’t have to completely remove that nut—you can just loosen it so it can wiggle off.

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Now that nothing is holding it on, we can work our belt off of each pulley. Sometimes spinning the fan blades makes it a little easier, but it’ll just come completely off.

If we’re looking at the mower from the back, this is how the belt should install: it should go around the engine pulley to the right hydro, straight across the front around the left hydro, and then around the idler pulley here in the middle.

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The idler pulley does have this bushing that sits there. You can tell this one’s real worn out—it’s been worn on that spot for some reason. There’s a very specific reason for that, which I’m going to show you how to fix coming right up. It’s because it’s slipping on that pulley. It shouldn’t be slipping—it should be tight enough, but the spring doesn’t allow it to pull tight enough with the setup it has.

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If your old belt is looking anything like this one (not the one I just pulled off), and there’s a bunch of cracks or bad spots in it—it should absolutely be replaced. Otherwise, it’s just gonna snap, and you’ll be right back in the same position.

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I always like to make sure the new one and the old one line up and are exactly the same size before installing. We always use OEM belts on these. You can use an aftermarket if it’s the same size. These ones aren’t too particular.

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That bushing out of the old one just goes in the new one. I’ll put part numbers for these down below. That goes up just like such, and then the washer and the nut hold it on below.

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Before you reinstall the belt, check all the pulleys. You can see here very clearly there’s a big piece of stick stuck in this pulley on the backside. If you leave that in there, it’s just gonna work your belt right back off again.

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We’ll work the belt first around the back pulley (the right pulley). Get it on there, then come to the front, then go to the left side and the idler pulley at the back.

You can remove this spring to get it out of your way if you’d like to. I’m gonna leave it just hanging here. Gonna install our bushing and idler pulley just up on top. We’ve got our washer and our nut—just starting it, don’t wanna tighten it down yet.

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Now we can move our belt around like it’s supposed to be, and you gotta make sure it goes inside this keeper. Now we’ll tighten it down.

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So again—the belt is inside the keeper here, and on all of the pulleys. If for some reason your belt came off, you can hook it back through again. You want to make sure that when it goes through there, this piece is to the upside—towards you.

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This is the way they tell you to install it, but not the way we actually do. It’s supposed to come back and just go right to this notch right here. That barely gives it any tension though.

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We are gonna install this spring just to show you what the fix is. If you look at the tension on the spring, there’s virtually zero tension when installed where it’s supposed to be. From the top side—just behind the battery—you can see this spring has very little tension. There’s only a small space between the coils.

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Here’s what we do to fix it on these models—so you don’t get those nuisance calls where belts pop off for no reason other than not having enough tension. Otherwise, they sit there and slip—which is why that idler pulley got worn down. It also wears the belt out faster.

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To fix our spring issue, I’m gonna take this spring back off using the spring puller. So it’s completely off. Now I’m gonna install it differently: hook side down into the pulley, and latch this piece all the way over here to this corner.

When you do that, it will bind up a little. Just push it like this—and now that spring has plenty of tension on it. Nice and tight.

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So again, instead of being in this hole, we’ve got the longer side and brought it all the way back to there.

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Now looking from the top, you can see there’s all kinds of tension on that spring. The belt’s not gonna slip anymore or come off.

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Now that everything else is hooked up, we can put our deck belt back on. Make sure it’s on all the pulleys up front. Then just bring it over to the side and roll it around.

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Everything should roll freely without issue. If it doesn’t, you’ve likely got the belt off somewhere.

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Roll it around so we’ve got our connection again. Plug it back in, and put this clip back where it’s supposed to be on the side.

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Let’s reinstall our bracket. Just gonna slip it into here, turn it until it lines up, get it started by hand—nice and tight.

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Take one more look around at the belt—everything is good.

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Well, hopefully this helps somebody out if you’re having the same or a similar issue with your Cub Cadet ZT1 Ultima. This is a design flaw in my opinion—there’s just not quite enough tension there. That’s why the belt slips and wears out quickly.

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I’ve seen this and done it probably 15 or 20 times in the last couple of years, and I’ve never had one come back. It puts plenty of tension there and the belt stops slipping.

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So whether your belt is broken, worn out, the idler pulley went bad, or you got a stick caught in it—whatever it is—hopefully I helped you get your issue figured out and back into working order.

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Don’t forget to hit that like and subscribe button if you enjoyed the content. Thank you for watching, and have a great day!

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Frequently Asked Questions FAQ

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Q: Why does the drive belt keep slipping off my Cub Cadet ZT1?
A: Common causes include worn idler pulleys, improper spring tension, or a cracked/broken drive belt.

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Q: Can I use an aftermarket belt on a Cub Cadet Ultima ZT1?
A: While some aftermarket belts fit, OEM belts offer the best performance and longevity for this model.

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Q: How do I increase tension on the drive belt?
A: You can relocate the spring anchor point to add proper tension and prevent the belt from slipping—shown step-by-step in the video.

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Related Searches:

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