Diesel Engines Timing Belt 01

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How not to change a cambelt!

- Jimmyt: I broke it!! .......fitting new cam belt and trying to undo the camshaft sprocket bolt, a big chunk broke off the end where my locking plate was fitted. Heres a pic of the damage....

- Thanks Jimmy, now we know to be careful! + - + - File:BrokenCamshaft JX.jpg + - + - Jimmyt: I used a straight piece of steel (all be it a piece of gauge plate that I ground on a surface grinder to be a precise fit in the camshaft slot ). I think the shape of the tool is important with the 'feet' that spread the load over a wider surface area which prevents the tool from lifting up and buggering up your camshaft. There was a lot of force going through my camshaft as the sprocket bolt was F tight so it needs to be securely locked. + - Lesson learnt, get the right tool for the job, and if your going to make the tool, make an exact copy of the tool as they are designed a certain way for a reason + - + - Simon Baxter: I have the tools, and have done a shed load of belts without that problem! + - When people say they have the correct tools, then go on to say it's a bit of bar they had... I wince every time. + - Im sure theres loads of people out there that have done the same without problems but I'm a great believer in using the right tool for the job. + - Thing is, to do the job properly you have to shim the bar up with equal amounts of feeler guages either side of the setting bar to get the cam timing bob on. + - + - Jimmyt: Well, its a lesson learnt for me, although in my defence I did post a question regarding this tool last week and the reply was to use a flat bit of steel. I used a decent lump of gauge plate (as opposed to mild steel) and did shim the tool with feeler gauges as per Bentley. As you say, this approach probably works most of the time but unfortunately didn't work for me, or I just messed up. + - + - + - HarryMann: Sounds like it was really done up idiculously tight (or might it have been already cracked, hairline? + - + - JimmyT sent this link, which although for a TDi gives a good account of these tools and using them... great photo-article, nothing missing, surely and a few what not to do's as well. + - TDi timing belt change + - + - JimmyT's home-made camshaft sprocket holding tool... + - File:Sprockettool.JPG + - File:Sprockettool1.JPG + - + - Diamond Hell: When you're fitting the new belt (and tensioner, right?) make sure that you've cracked the sprocket off the cam by belting it from behind with a punch, as directed (people miss this bit) - this means it will spin freely on the cam and make tensioning the belt a lot easier (Russel at Syncro-Nutz pointed that bit out to me - what a great tip). + - + - Of course the cheat's way of doing this is to cut the belt in half around it's run and lose the outer half. Once you've done that the new one can be slipped over and re-tensioned. Easy, cheating, but effective. + - + - Louey: - can take just as long and you can risk damaging the new belt if you force it too much + - + - andysimpson: - 9 times out of 10 with the all VW diesels the tensioner is the cause of breakage. It is supposed to be replaced when belt is which means the belt has to come off anyway, before tensioner can be replaced. + - + - + - JimmyT: - Thats sound advice from Diamond Hell regarding doing stuff in the right order. The two manuals I've got tell you to lock the camshaft first with the plate then loosen camshaft sprocket bolt, I guess this works OK if the bolt is torqued up correctly, but its definitley worth cracking the nut loose before doing anything else.