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MugenNeuspeed

Timing Belt Tensioner Problem

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Alright I got a 98 mazda 626 2.0L.

I am changing my timing belt and I am just about done.

I got a timing belt component kit and replaced the idler pulley and the timing belt tensioner and the spring with it.

When I go and tighten my idler, it rolls freely, which is perfect.

I then proceed to tighten the 14mm on the belt tensioner. I tighten it pretty hard, however, when I go and use the allen key to loosen it so I can slide the timing belt on, it is very tight, and barely has any play.

However when i loosen the 14mm a little, then i check the tensioner again, it rolls freely.

How tight is too tight when tightening the belt tensioner, I mean I get no rebound if it is too tight, and I am afraid this could cause my timing to jump, however if it is too loose, I'm afraid the 14mm bolt will back out and cause my timing belt to snap. What can I do to assure I won't run into any problems

I am extra paranoid because I don't want to mess up.

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I don't know if you can get a torque wrench somewhere (or you can guess the applied torque by hand)?

Both idler and tensioner should be torqued down to 27-38 Ft-lbs (approx. 36-51Nm)...(if your wrench is 40cm long, you have to pull with a force equal to approx 10 kg)

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Verifying that it is suppose to pivot freely with the pressure of the allen key correct?

Thanks I'll go grab some thereadlock

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I have a 98 2.0 626 LX and just changed my timing belt and tensioner and all other related parts. I bought all the parts and noticed that the tensioner roller would roll freely but was very difficult to turn about the axis of the bolt. I went to the Mazda dealership and talked to a mechanic and he said this was normal. He told me to install the tensioner and tensioner spring but do not tighten the tensioner bolt all the way(leave it so the tensioner can move freely). Install the timing belt and then rotate the crankshaft a couple of revolutions to see if your marks still line up. This will put the tensioner where it should be and now you can torque it down to spec. Hope this helps.

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i have a 97 and there was a recall on my tesiner or whatever u said but thats my year so whos knows just thought id share that

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Well there seems to be a consensus; I've got a '96 with 120k and had to replace the tensioner at 110k after it was stumbling the timing belt.

I suppose there should maybe be a pinned post about this?

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I took my tensioner to the dealership and asked the mechanic if my tensioner needed to be replaced. He said it did because the tensioner spring had started to wear a groove in the hole where the spring attaches to the tensioner. The new (redesigned) tensioner has a sleeve inside the hole where the spring attaches to the tensioner to prevent the spring from wearing a groove in the tensioner and causing the spring to break.

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I have a 98 2.0 626 LX and just changed my timing belt and tensioner and all other related parts. I bought all the parts and noticed that the tensioner roller would roll freely but was very difficult to turn about the axis of the bolt. I went to the Mazda dealership and talked to a mechanic and he said this was normal. He told me to install the tensioner and tensioner spring but do not tighten the tensioner bolt all the way(leave it so the tensioner can move freely). Install the timing belt and then rotate the crankshaft a couple of revolutions to see if your marks still line up. This will put the tensioner where it should be and now you can torque it down to spec. Hope this helps.

I took a look at my Dutch mazda workshop manual, and it did indeed say to first install the timing belt, then turn the crank a full turn twice, and then torque down the tensioner, and finally turn the crank a full turn twice again....so that seems to be the best way to do it, if the tensione has been removed!

I took my tensioner to the dealership and asked the mechanic if my tensioner needed to be replaced. He said it did because the tensioner spring had started to wear a groove in the hole where the spring attaches to the tensioner. The new (redesigned) tensioner has a sleeve inside the hole where the spring attaches to the tensioner to prevent the spring from wearing a groove in the tensioner and causing the spring to break.

This is very useful information! When changing the T-belt in a few months, I will take a very good look at the spring attachment site of the tensioner to look for problems there....

Do you happen to know from which year the redesigned tensioner was installed from factory? I just know that my tensioner has never been replaced (awfully expensive over here: >US$200 for only the tensioner)..

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Sorry, I don't know what year the design change happened. I can only assume that all tensioners without the sleeve have been changed. If its any help, I will post a picture of the one I replaced that had the groove in it.

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Sorry, I don't know what year the design change happened. I can only assume that all tensioners without the sleeve have been changed. If its any help, I will post a picture of the one I replaced that had the groove in it.

That would be very helpful indeed (probably not only for me ;) )!

Edit:

Is the opening in the picture below (with the red arrow) what your are talking about...and this would be the improved version?

tensioner.JPG

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No, that is not the hole. I will take a picture when I get home this evening and post it.

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Hope this picture shows where the spring wore a groove in the hole where the spring is retained. This is the backside of the tensioner and you can see (middle/left side of picture) that the hole looks like a keyhole now.img-222916-1-MVC-024X.jpg

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Very clear picture, thanks!

I'll certainly remove the tensioner next TB-change to be sure whether it's still OK...

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