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Discussion Starter #1
Yeah, I know, who needs a write-up for something this easy?

Well, not everyone on the board does SAS on their Broncos on the weekends. Some people just might want to wrench a little on their DDs. This is a simple thing to get them started, and my first attempt at a write-up.

So, here we go:

When I changed the belt on my 5.0, I noticed that the tensioner didn't return very strongly or smoothly. The idler pulley was sticky as well (though I didn't notice this until I was doing the tensioner swap already.) I also occasionally have low voltage at idle, so I figured replacing these old parts wouldn't hurt anything, and might help my belt tension stay a little more constant.





I picked up the new tensioner from Ford, but got the idler pulley from a local shop this weekend. I'd rather have a steel pulley like the tensioner, but this'll do. At least it was cheap.





First step is to disconnect the negative terminal on the battery. You *really* don't want the engine starting while your hands are in the fan/belt area.



Second step is to remove the belt. Using a 15mm socket on the tensioner pulley bolt, rotate the assembly counter-clockwise to relieve the tension, and slip the belt off the idler first. Then you can just pull the belt out of the way.



Third step, remove the tensioner. It takes a T50 Torx bit, and it has a normal right-hand thread. I had to put a wrench on the pulley bolt again to break loose the mounting bolt.



New vs. old



Here's the mount on the engine. The blurry tab sticking out is what the tab on the body of the tensioner presses against (where you can see the non-rusty vertical scratch).



Here's a shot of the new tensioner part-way on. You can see that the tab on the body of the tensioner is against the tab on the engine.



Here's the tensioner all the way on. Tabs are more obvious here, and the spring has been pressed together like the old one was.



I needed to extend my little breaker bar a bit to get the bolt loose on the idler, so I used my jack handle. This is usually a *bad* idea, and you can break tools really quickly doing this, but in this case it was exactly enough to make it really easy to break the idler bolt loose. This bolt is also a normal right-handed thread. I used a T50 Torx bit, which worked, but I'm not certain that was the right size, it seemed a little loose. I had to clean a lot of sand out of the head of the bolt as well.



Old and new. You re-use the bolt.



Here's the mount for the idler. Just screw in the new one with the old bolt. (and ignore the coolant seepage) Then you can put the belt back on (again, relieving tension with the 15mm socket on the tensioner pulley bolt). Read your manual or the sticker under the hood if you can't figure out or remember how the belt is routed. Tip: smooth pulleys get the smooth side of the belt against them, ribbed pulleys get the ribbed side. And if you find yourself trying to get the belt to go around the fan blades, you're probably doing it wrong.



Here are the two new parts installed. Prettier, no?



I gave a small blood sacrifice to the knuckle god, so this was a pretty normal wrenching session for me. Total time, if I hadn't been taking pictures, 20 minutes.
 

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Good write up. Thanks!!! :thumbup
 

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where the hell were you four years ago? the pulley on my tensioner DISINTEGRATED while i was on the highway. wrestlin' that bronco to the side of the road was a bee-yotch.
 

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Discussion Starter #4
SoCal XLT: Everything is nice and smooth now, and a whine I used to have at idle has gone away. My voltage seems to read even higher at idle now too, which is nice.

Joes93Bronco: Yeah, my idler pulley on my 4.0 Ranger seized on the highway, and unscrewed itself from the block. I pulled over to find it lying on the block, with the belt hanging loose. That was pleasant.

Mods: Can you add a 56K warning to this post, if necessary? I can't edit the title. Thanks.
 

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sewiv said:
SoCal XLT: Everything is nice and smooth now, and a whine I used to have at idle has gone away. My voltage seems to read even higher at idle now too, which is nice.
Awesome...... Nothin beats takin' something that aint workin' well...... and fixin it so it works the way its supposed to!!! Mission accomplished!!:rockon
 

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squealing at start up

Hey there I recently swaped out my alternator, serpertine belt, and put back on my stock pulleys. It now squeals for a few seconds when I start it up. I have tried putting belt dressing on the belt, but it doesn't seem to help that much. A guy at a shop said it could be the tensioner or the fact that that the pulley on the alternator is painted. Its a Mean Green alternator and they come with the pulley painted green. Any ideas or do you think it the tensioner?
 

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Discussion Starter #8
Pull off your belt. Spin your tensioner pulley by hand. It should spin smoothly, not notchy or tight. Same thing for the idler pulley. If the tensioner pulley is tight or notchy, you can just replace the pulley, you don't have to replace the whole tensioner. My spring was weak, so I replaced the whole thing.

And yeah, the green paint, depending on what kind of paint it is, could be pretty slippery, which would cause belt squeal.

Check that the alt. turns freely with no load, as well. While the belt's off, check that all the accessories turn as they should, and check end play (tug forwards and push backwards) on the water pump pulley. It should be pretty tight. If not, your water pump could be going.

Basically, check that there's nothing that is really hard to start spinning, because that's probably where the squeal is coming from, something that's taking a while to spin up to operating speed.
 

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Thanks for the info I'll check em out!
 

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Mine came with the bolt, it was a straight R&R, as easy as lard is greasy, and it fixed all the belt squal I was having too! Mine was about $40 IIRC.
 

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sewiv said:
I picked up the new tensioner from Ford, but got the idler pulley from a local shop this weekend. I'd rather have a steel pulley like the tensioner, but this'll do. At least it was cheap
i got a new idler pulley from napa that was steel. it looks like the pulley that came on your tensioner. the same thing happened with my jeep. it had a plastic, but the replacement was steel. i like them much better.
 

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Discussion Starter #13
I have since checked, and the idler pulley bolt is a T50. I tried a T55, and it was way too big. I think the sand in the bottom of mine was making the T50 bit fit funny.
 

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OK- I recently replaced my idler pulley as it was a little sticky and I was getting a squeal @ approx 1800rpm. No change in the squeal! This morning I started the Bronc and the belt began to shred. I replaced it and still the same squeal. I checked all the other pulleys and they all are smooth rolling and I have not had the A/C or defrost compressor running when this has occured. Any ideas???
 

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burger213 said:
OK- I recently replaced my idler pulley as it was a little sticky and I was getting a squeal @ approx 1800rpm. No change in the squeal! This morning I started the Bronc and the belt began to shred. I replaced it and still the same squeal. I checked all the other pulleys and they all are smooth rolling and I have not had the A/C or defrost compressor running when this has occured. Any ideas???
It's going to take a little detective work on your part. Take the serp belt loose and try to rotate each of the pulleys by hand, that should show you where the problem lies. Recently the A/C compressor on our Taurus went south and started making god-awful belt noises, that is how we diagnosed it.

And on another note, I just replaced the serp belt tensioner on the 5.8L in mine, made a big difference. Ever since I replaced the belt and upgraded to a 3G alternator my belt had been slipping on startup, with the new tensioner it doesn't make a sound.:thumbup
 

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I've checked all pulleys that can be rotated with the belt off and each one seems to roll smoothly. The compressor has not been engaged when this occurs. It only does it when I'm slowly climbing through the RPM's around 1800-2000 then disappears. It doesn't squeal at any other time. I believe it's the original alternator. Could this be causing it by creating drag @ certain RPMs?? The alt pulley seems okay by hand. The tensioner is original but seems to have plenty of tension.
 

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Joes93Bronco said:
where the hell were you four years ago? the pulley on my tensioner DISINTEGRATED while i was on the highway. wrestlin' that bronco to the side of the road was a bee-yotch.
Same thing happened to me a couple of months ago. The bearing in the pully siezed melted the plastic pulley and shot it out from under the bronco. Had to get towed to the auto parts store in Topeka to get parts. It sucked

Adam
 

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Thanks for the write up

Thanks for doing the write up, but I cannot seem to find the t50 Torx bit anywhere, went to Advance, they were out, Lowes, out. Any thoughts? i saw plenty of kits for $14.95 that had the bit in it, but I don't need all the other sizes.

Thanks
 

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Discussion Starter #19
Best suggestion is to look in the phone book for auto parts suppliers or hardware stores. It's not that uncommon a thing.

If you are only buying a T50, you're probably going to pay $3-5. If you *ever* need another one of the bits in the kit, you're going to kick yourself. I'd just spend the $15 and be done with it.
 

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Juice52 said:
Hey there I recently swaped out my alternator, serpertine belt, and put back on my stock pulleys. It now squeals for a few seconds when I start it up. I have tried putting belt dressing on the belt, but it doesn't seem to help that much. A guy at a shop said it could be the tensioner or the fact that that the pulley on the alternator is painted. Its a Mean Green alternator and they come with the pulley painted green. Any ideas or do you think it the tensioner?
I have a mean green on mine, when I went to install it, they have in their paperwork that if the belt squeels to get a little shorter belt. I believe they say that because the pulley is smaller on the new alternator.
 
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