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Discussion Starter #1
Here's a fun one.

Recently (November of 2015) I did my timing belt and timing tensioner and idler. I have the special cam holder and crank pin, and a torque wrench and everything. I've done timing belts in the past on many other cars. I promise I'm not an idiot or anything lol.

Since I've been doing a lot of work on my car lately, I left the upper timing cover off (shame on me, I guess) and while changing my oil yesterday, I ran my finger under it just out of curiosity (under the t-belt between the cam pulleys) and it felt like it had slack in it. Not like normal, but pretty loose. So I looked at the tensioner, and it's right where it's supposed to be, it didn't back off or anything. The cams are perfectly aligned.

Do the timing belts just kinda stretch and break in? Am I freaking out about nothing? I'll check over everything again, but I'm pretty thorough.
 

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Old Phart
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Kinda "break in" and sit in the cams better, loosening them up.

When someone goes back to readjust one after running, it ends up with too much tension and tends to "walk" off the side of the pulleys.
 

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FYI even with brand new they set with MUCH less tension than oldschool belts did, why they last so long. Anything with VCT can actually be loose enough to remove belt without loosening anything, I've done it. Having said that there really should be no true 'slack' there, just seem loose.
 

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Discussion Starter #5
That's really what it is, just feels looser than I thought it'd be. Hasn't given me any trouble and it's not even starting to wear the printed-on markings off yet.

Sent from my SGH-T999 using Tapatalk
 

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That's really what it is, just feels looser than I thought it'd be. Hasn't given me any trouble and it's not even starting to wear the printed-on markings off yet.

Sent from my SGH-T999 using FF Mobile
Take a kind of close up picture of the tension indicator on the pulley with it cold.
 

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That will be misleading, the initial tension drops off as belt breaks in, 10 minutes and done. As well, depending on where parts stop moving when engine is shut down the crank can relax in one direction based on cylinder pushback and the cams in another from valvetrain friction (spring popback)to make apparent slack where there is none averaged out and engine running. Why VCT ones can be so loose, they even let the cylinder leak down at sitting to add much more to that. Crank back up and runs forever. I'm of the thinking that belt relaxes to have no tension at all at end of belt life and intended that way.

Stop engine several times and you can easily get several different indicator readings there. They don't even stay the same rolling motor around while timing it, the parts give and take makes it jump around; all you can do is average it out in your head. Why the Ford timing method kinda sucks, you are making a single point misleading setting that could change easily to be mostly off as soon as engine is moved. Why I always roll engine around several times to look at the tensioner action when timing. One spot checks are incorrect there.

Ford says once the belt has broken in you should not be even using the tensioner to set tension with as the belt has already done the drop off in tension, new belt required once you're past that 10 minutes. Doing so makes it too tight. It CAN be done but you set low in that case, put right on the range mark and odds are the belt will then edge ride. Too tight.

These are so easy to make too tight and what makes the belts edge ride so much. The common error. The belt edge rides once there is enough friction (belt too tight) to then begin to make it migrate one way or the other depending on pulley wear. The crank guides are intended as kisses rather than hard bumpers, if you bump or pull toward a guide rail hard enough the belt then begins to seek it to edge ride up it too. Edge of belt weakens to then fold and roll right up the guide surface. Since these are only guided at crank then everywhere else the belt is then slightly over the edge of pulley to fray the edge, that belt is then history in a short time.

If belt is running away from pulley edges then leave it alone, many would kill to get that having set belt too tight to walk it. They just don't get it. 'It's a belt, it's supposed to be tight' they think..............
 
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