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Discussion Starter #81
Yeah I know what youre saying but if you spin this tensioner there’s no resistance hardly and even the one I failed to tension doesn’t has some so I wonder what happens if the engine jerks the belt surely there should be some rotational resistance in the tensioner bearing but there seems to be hardly any it just freewheels! What I have noticed is that the profile of the belts are slightly different in the gates and alfa ones the teeth are rounded but the Dayco ones are flattened on top with a furrow down the middle maybe the car’s worn used to the rounded type I really thought the Dayco would work ok as you say they’re a top company OMG this has been a learning curve!
 

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Resistance to spin or not when new is probably due to resistance caused by the end seals. I've not seen one which freewheels when new though. There may be developments in the bearings since I last fitted one. If you are not happy, contact Gates technical. I thought they used Canadian made tensioners. Ensure you purchased from a known good supply chain as Gates is one of the many companies which has suffered from counterfeiting. Hopefully that is not the case though.

Differences in the belt teeth are due to different manufacturers using different features to ensure the belts are quiet and reliable. Dayco was, possibly still is the OE supplier for Alfa, ditto VAG. Gates tend to make belts of exceptional quality and are possibly the most innovative manufacturer. I have only ever fitted Gates or Dayco to Alfas and I won't change this.
 

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Discussion Starter #83
Thanks Fruity yes the mounting plate is inscribed made in Canada I got this kit a while ago on eBay and although the dimensions etc seem fine the free spin in it concerns me so I’ll ask Gates as you suggest. I’ve also dug out a genuine Alfa kit from 2007 that’s good for the car that again I picked up a few years ago for a few quid thinking that even if it was unwise to use an old belt the other bits would be ok but after doing some research it seems there were some issues with the tensioners in those days so now I’m not so sure although apart from one extra code on it the tensioner is exactly the same part number as the one that came off the belt itself is an old part number but correct for the car there’s quite a wide school of thought on the shelf life of belts isn’t there? Guess it depends how they’ve been stored
 

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The thing with tensioners was originally plastic was used to reduce wear on the belt teeth. Unfortunately the original black pulley tensioners could break apart catastrophically so a revised white pulley tensioners was introduced.

Unfortunately this did not fix all the reported failures so finally metal pulley tensioners were introduced. Unsurprisingly, around that time or a bit afterwards, the replacement interval was dropped to 36k miles.
 

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Discussion Starter #85
The thing with tensioners was originally plastic was used to reduce wear on the belt teeth. Unfortunately the original black pulley tensioners could break apart catastrophically so a revised white pulley tensioners was introduced.

Unfortunately this did not fix all the reported failures so finally metal pulley tensioners were introduced. Unsurprisingly, around that time or a bit afterwards, the replacement interval was dropped to 36k miles.
The tensioner in the Alfa kit is metal so perhaps it is ok I am thinking of using the Gates belt with a compatible idler and tensioner I can’t see that there would be an issue with that
 

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Discussion Starter #86
Once it’s torqued up does the tensioner backplate slide when engine runs or is it just toothed wheel?
 

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Discussion Starter #87
I set it up again with another belt but now finding TDC on the dial is extremely hsrd the dial is showing different positions for it every time I try to locate it I’ve looked down the well of No1 cylinder can’t see anything like carbon bits causing it any ideas please?
 

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The backplate won't move once it is all torqued up. The nut holds it in position so the spring on the eccentric tensioner pulley exerts tension which changes depending on engine position. That is a dynamic tensioner. A static tensioner would lock the tensioner pulley in place which would then not move so the tension on the belt would vary if the engine is warm or cold.

If it now appears to not be on TDC for cylinder no.1, use a thin long screwdriver down the plug hole to find rough TDC position. Remember to reposition it on the way up to ensure it is straight and does not bend. Failing that, you have incorrectly positioned the TDI gauge in the pillar. When doing it I often do not clamp it in tightly so that is can slide up if I have set it to the wrong height. That avoids damaging the DTI gauge.

Have you looked on YouTube for videos on how to do this?
 

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Discussion Starter #89
Thanks Fruity. I watched a U tube video of guy doing the belt on the same car he tensioned the belt using an alum key as a hook to pull the pointer up I believe but I’ve used the proper tool and still struggled. I’ve reset the camshafts with the locks slackened off the camsprockets again and taken the belt off. I will have to check the way I was using the DTI didn’t have any issue with it till today job fatigue probably. Ive pretty well lost hope of ever getting the tensioner to stay at the right setting however many times I put it there and I’ve done everything so meticulously I wonder if there’s not another issue I’ve missed I even lined the belt marks up both times with the marks on the crank and the exhaust sprocket when fitting which I don’t think most bother to do. If you can think of anything that might be the proverbial fly in the ointment please let me know! Cheers
 

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Discussion Starter #90
Just want to check some of my working on fitting this cambelt with you guys.
So crank is at TDC on no1 cylinder camlocks are both in place tensioner and idler have been installed but tensioner nut is not tightened both cam sprockets are loosened off. Then new belt is put on maximum tension applied. Next 4 inlet pulley bolts tightened to 12Nm with threadlock. Next exhaust cam pulley bolt torqued to 117Nm and threadlocked. Care was taken to ensure both sprockets were rotated clockwise when belt installed. Camlocks removed engine turned twice (or buggar, I’ve missed TDC and go around again) camlocks still fitting perfectly at TDC tensioner nut slackened and using tool attempt is made to align needle with hole at TDC seems very difficult a number of adjustments made till it looks right when viewed from under wheel arch. Engine rotated again twice to TDC camlocks still fitting but tensioner needle has dropped to below hole at TDC why???? Further adjustments to tensioner setting it at various positions above hole to try and randomly accommodate drop in position on rotating engine and on a couple of tests pointer is in right position then drops again so no satisfactory solution obtained - tensioner still setting incorrectly. Now, I’m torquing the tensioner lock nut to 25.2Nm is that enough? Alfa Workshop say 24-26Nm I didn’t want to strip the thread on the rod so put it at 25Nm ish as there’s no obvious way of repairing thread if it pulls out. Be grateful for your further help please.
 

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When you go for tdc are you setting and locking cam first then doing crank, or are you spinning over getting to tdc on crank and then seeing if locks drop on?

mate you using dial gauge after spinning over 2 turns or did you find tdc with dial and then put a deference mark on crank sprocket and block?
 

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Discussion Starter #93
First I see if locks go on using dial at tdc if they do fine if not I adjust cam shafts with belt off so they are perfect fit. Once locks on I check tdc on crank with dial it may need a tiny movement one way or other then I put belt lightly over crank sprocket and attach 19mm socket to crank bolt on breaker bar clamped to caliper to make sure crank doesn’t move. Then I do steps above.
I’ve always used the dial Johnny from start to finish haven’t used tippex at all.
I spoke to Alfa mechanic earlier he said so long as you set the tension so pointer is over hole at TDC it doesn’t matter what the pointer does after that he said pointer doesn’t have to be over hole when it’s idling - maybe this has been my error? He said he uses a mirror to get pointer at centre of hole I’ll have to have another go.
 

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Discussion Starter #94
So maybe reason why Im thinking it was all wrong when I saw ponter below hole at tdc after rotating engine a few times is because I was not turning it with constant force so the tension was changing according to the applied load does that add up?
 

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I spoke to Alfa mechanic earlier he said so long as you set the tension so pointer is over hole at TDC it doesn’t matter what the pointer does after that he said pointer doesn’t have to be over hole when it’s idling
What I said ages ago.

As long as tensioner pointer is very approximately in position after turning engine it is ok.

You now have plenty experience in doing the belt so just fit it and use it.
I've done enough so I don't bother doing all that checking. I turn the engine by hand to make sure there is no interference and then use it.
 

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Discussion Starter #96
Yes I’ve overthought it also having to do it piecemeal on a several occasions hasn’t helped I’ve redone it everythings looking good I can even get the belt on round the water pump now so tomorrow after work I put battery in and start up thanks everyone for all the support and excellent adviice
 

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I am pretty much like fruity says, set up on DTI initially so you know it’s correct but I also then reference mark crank and block so when spinning over by hand I can line it up without using DTI again.

git to be honest though I run the engine and make sure pointer is around the mark when idling. Just something I have always done since vauxhall days and never had an issue.

may least when it’s due again you will be able to fire the belt in no problem. Been a bit of a ball ache for you this one has. I suspect you may have had a dodgy tensioner given the hassle and grease loss.
 
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