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Timing Belt Tensioner orientation

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Old 04-03-2006, 11:16 PM
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austin944
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Default Timing Belt Tensioner orientation

The FSM shows the timing belt tensioner installed two ways. On page 15-4, it shows the eccentric pointed "up" and it says to turn the tensioner anti-clockwise to tighten. But on page 13-3, they show the tensioner eccentric pointing "down" and you would turn the tensioner clockwise to tighten.

The Haynes manual also shows it installed two ways. In the picture 8.3 on page 56, the tensioner eccentric is pointing down, and in picture 8.17a/b on page 59 the eccentric is pointing up.

I am thinking that the correct orientation is "up" as shown on page 15-4 of the FSM, since there is accompanying text which is consistent with the picture there.

What say you all?

The engine will run using either orientation, and can run for quite a while that way. (Don't ask me how I know).
Old 04-03-2006, 11:36 PM
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Granite 944
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IF........ya really look at it good. You can tell which way to turn the tensioners on the camshaft, AND on the balance shaft tensioners. They are each turned in different directions.

The balance shaft tensioner turned counterclockwise, will put the belt closer to the belt cover, not good. Clockwise is correct. IIRC! I haven't looked at it lately! Study the diagrams in Clark's garage again? I'm sure someone will correct me, if this is wrong.

The cambelt tensioner should be turned the opposite direction. Counterclockwise.

Hope I got this right! Look at the position of the balance shaft tensioner. Stay away from the side of the cover. The camshaft belt is turned the opposite direction.
Old 04-04-2006, 12:03 AM
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The text in the FSM is consistent with what you say but there's no consistency in the pictures.

In Clark's Garage, it's hard for me to tell, but it looks like the first diagram has the cam tensioner eccentric pointing "down", which would mean clockwise to tighten. Same in the first picture. In the text, it says to turn counter-clockwise, but it doesn't say whether that's to tighten or loosen.
Old 04-04-2006, 12:12 AM
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Clark's garage description IS a little confusing. I agree. BTDT. Study it more. Hopefully, a few more people will jump in that have BTDT, and will confirm.
Old 04-04-2006, 12:30 AM
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Tom M'Guinn

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As I understand it, from the turbo supplement manual:

Turn the timing belt tensioer counter-clockwise to tighten. (15-3)
Turn the balance shaft tensioner clockwise to tighten. (13-6)
Old 04-04-2006, 01:02 AM
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Yabo
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umm not to hijack, but maybe this will help both of us. I didn't even think of which way to do it.. does this look like i did it wrong?
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Old 04-04-2006, 03:20 AM
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Tom M'Guinn

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I can't tell from the picture. I do know that the balance shaft belt can get too close to the rear cover if you tension it counter-clockwise. Ask me how I know...
Old 04-04-2006, 01:57 PM
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Originally Posted by yieldsign2
umm not to hijack, but maybe this will help both of us. I didn't even think of which way to do it.. does this look like i did it wrong?
It looks like that pic shows the timing belt tensioner setup for clockwise-tighten (eccentric pointing "down") and the balance belt is setup for anticlockwise-tighten.

The text in the FSM says the timing belt tensioner should be anticlockwise-tighten (but the pictures show it both ways), and the text says the balance belt tensioner should be clockwise-tighten.
Old 04-04-2006, 02:08 PM
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Tom M'Guinn

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Originally Posted by austin944
The text in the FSM says the timing belt tensioner should be anticlockwise-tighten (but the pictures show it both ways), and the text says the balance belt tensioner should be clockwise-tighten.
I'm not sure I understand what the picture is showing both ways? I don't think there is a "correct" direction for the accentric to point, as long as you tighten in the correct direction (as you list above).
Old 04-04-2006, 02:31 PM
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Originally Posted by Tom M'Guinn
I'm not sure I understand what the picture is showing both ways? I don't think there is a "correct" direction for the accentric to point, as long as you tighten in the correct direction (as you list above).
When I say "the pictures show it both ways", I'm talking about the two pictures in the FSM on pages 15-4 and 13-3, which show the eccentric pointing "up" and "down", respectively.

The direction in which the eccentric points always determines the direction of rotation for tightening the tensioner (and vice versa). They are in a sense equivalent. So the eccentric postion does matter, if we agree that the tightening direction matters.
Old 04-04-2006, 04:02 PM
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Tom M'Guinn

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Well, i agree the direction of rotation matters. I just never took note of which way the accentric points ... and assumed it didn't matters since the manual doesn't mention it. Does the actual gear change position depending on which way the tensioner points?
Old 04-04-2006, 05:54 PM
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It's easy, the timing belt tensioner should be tightened in the counter-clockwise direction. The tension on the tightening bolt will always want to tighten it (the tension of the running timing belt will exert pressure on the tensioner in the clockwise direction). If you tighten the timing belt tensioner clockwise, then the tension from the belt on the tensioner will always be in the counter-clockwise direction - the way you turn the nut to loosen it. Mind you, if the nut is torqued down to 33ft-lbs then it shouldn't matter, but I'd rather do mine the correct way. Lots of miles, and lots of vibration/tension on that nut to want to loosen it.

The balance belt should be tensioned clockwise. There isn't much tension on that one, and it's not critical if it loses a bit of tension and skips a tooth or 10.

Yieldsign2 - you're timing belt tensioner is tensioned incorrectly. As is your balance belt tensioner. Also remember for the balance belt, the idler should have .5mm between the idler and the balance shaft sprocket, it also should just barely touch (I like it to barely touch) the top run of the belt. It's only purpose is to take out the harmonic wave of the long run of the balance belt. I also hope that you are going to change out that rusted idler on the timing belt run. You may not think it touches, or makes a difference, but if it seizes then you WILL take chunks out of the surface of the timing belt.


Dal.
Old 04-04-2006, 06:11 PM
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Originally Posted by Tom M'Guinn
Does the actual gear change position depending on which way the tensioner points?
Yes. When it's installed in the counter-clockwise tightening position, the timing belt gear is a little closer to the water pump pulley than it would be if it were installed using the clockwise tightening position.
Old 04-04-2006, 06:44 PM
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Dal, thanks, i thought i read clarks pretty close but didn't even notice there was an issue of which direction you tighten the belt. I guess i'll redo it before I take it off the stand.

Also, i hadn't oriented the balance belt idler yet so that's why it is in teh wrong place, it's just sitting there untorqued for now.

And thirdly, that idler roller is brand new, the seal is brown, it's not rusted.
Old 04-04-2006, 08:16 PM
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Originally Posted by yieldsign2
And thirdly, that idler roller is brand new, the seal is brown, it's not rusted.
Ahh cool, It just looks like rust on the picture.

My bad.

Dal.



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