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DanVW

Crank keyway sheared - not any more :D

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Hi All,

 

 

My G60 has been off the road for a month or so now, due (I guess) to a certain garage re-using the (stretch) crank bolt during an engine rebuild in 2003! Now I have managed to get everything off (was able to undo the crank bolt by hand it was that loose!!) It's quite clear that when the keyway sheared it ruined the pulley and chewed the end of the crank shaft, however I would just like to know if anyone here has either cut a step out of the chewed crankshaft and made up a custom keyway to fit it? Or maybe a blob of weld and ground it back flush? The local crank specialists and engineering firm's I have spoken to regarding this idea has said "Nope just pay us to fit a new crank!" but to my eye's the damage to the Crank shaft doesn't look that bad, can I have some more experienced opinions please? (Ref attachments)

 

P.s all those going to the south coast meet on sat see you there :-)

 

Cheers

 

Dan :D

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There is a special tool to re-face the end of the crank, there's a demo of it on a thread on Club GTI forum. A similar thing happened to me and I got away with filing the rough edge of the keyway flat and bolting on a new pulley. It's the torque on the pulley bolt that holds it in place so providing you can get a new pulley on flat it should be OK.

Mine had a new pulley thousands of miles back when this happened and is still OK on a modified 2.0 16v.

 

David.

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have a search on vwvortex.....a few people have drilled through the pulley and into the crank in 2 places and fitted a roller bearing to act as a pin

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Hello mate.....

 

Interesting to hear what is being said....

 

TBH it looks like there is over half of the depth of the keyway still intact, have you tried slotting that new key in and seeing what it's like? Maybe that idea with the chemical metal to fill the little gap coud work, and then as steveo said drill it and loctite a pin or two through the pulley into the crank? At the worst it would knacker the crankshaft.

 

Also it'd be nice to hear some thought on fitting a new (secondhand) crank....

 

Supposing we were to take the one from my spare 16v block, get it ground and get new shells for it, I suppose we'd need the original g60 flywheel bolted to it. does this need balancing to the crank?

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I was thinking everyone would say don't dick about just slap in a new crank shaft but its very encouraging to hear someone else say they just reground the end of the shaft and put a new pulley on it! The only problem so far is that I think VW Parts department have given me the wrong keyway as its half the size of the notch in the crank shaft!! :roll: will find out on sat morning when I get the new pulley. Thanks for the advice everyone but another quick question should the keyway be a snug fit in the crank shaft slot? As I guess it should be!

 

Cheers all

 

Dan

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Yes, the key should be a tight fit into the keyway, it needs to be gently tapped in. I assume that this pulley drives all your ancilliaries including the G-lader, so the shear force on the key is very high unless there is a high frictional component at the mating faces of the pulley and the crankshaft. I doubt if they are a tapered fit. Does the damaged edge extend along the full length of the slot

 

The reason I can think of against your plan of drilling and pinning the pulley onto the crankshaft is how do you get it off again if you ever need to? If you use a needle roller it would be too hard to drill out, so the only solution would be to drill right through and use a pin that could be driven out the other side if necessary. Is the end of the crankshaft hardened? If so you may again have trouble drilling it. And you will need quite a large diameter pin(s) to get the shear plane area you need equivalent to the original arrangement.

 

I think the ideal solution is to have another slot cut into the end of the crank opposite the damaged one; it isn't too difficult once the crankshaft is out to grind or mill a slot. Are there timing marks on the pulley? Obviously they would be useless if you move them relative to the crankshaft.

 

Best wishes

 

RB

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Have just added a few shots of the keyway I have, think it’s fairly obvious that VW parts department don’t know their EKTA from their elbow! :roll:

 

Anyway cheers for the suggestions but unfortunately as the crank pulleys are marked both to line up with the intermediate shaft and the bottom cam cover, cutting a new slot in the crank is out of the question unless I cut a notch 180 degrees out on the pulley too, not sure if I have the tools or the experience to attempt it really! :oops:

 

You around sat before the meet tom? No worries if not I will bore you to death with it in the afternoon anyway :D

 

 

Cheers all

 

Dan

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If it’s only worn on one side and you can make sure the lower gear will sit in the correct position then you could pin it, better done by and engineering company tho.

 

I’ve done quite a few (other makes tho) and not had a problem but there are some that are beyond repair.

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You around sat before the meet tom? No worries if not I will bore you to death with it in the afternoon anyway :D

 

I can be.... but i was planning to get a bit of a lie in and wash the car. Maybe hoon over Sunday? the traffic should be a lot quieter then too. It'll be interesting to see how the new pulley fits, especially with a proper key. I hadn't thought about the extra torque on the key from driving the charger.... hmmm. I'll have a bit more of a think about it.

 

Tom

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No worries mate will be snowed under sat morning anyway due to unforeseen circumstances, cant really do much on the 60 till I get the correct key from VW anyway so will make a start on flatting off the edge and corner of the shaft,

 

*btw thanks for the offer Crasher very kind of you! but the shaft doesn't look too bad on the face just round the edge so as above I am going to try and carefully grind it flush and hope for the best!

 

Will keep everyone posted as to progress thanks again for the advice an top tips!

 

 

Cheers

 

Dan

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No worries mate will be snowed under sat morning anyway due to unforeseen circumstances, cant really do much on the 60 till I get the correct key from VW anyway so will make a start on flatting off the edge and corner of the shaft,

 

*btw thanks for the offer Crasher very kind of you! but the shaft doesn't look too bad on the face just round the edge so as above I am going to try and carefully grind it flush and hope for the best!

 

Will keep everyone posted as to progress thanks again for the advice an top tips!

 

 

Cheers

 

Dan

 

I know it's not ideal, but it worked for me and the damage looks very similar, BTW although the 16v doesn't drive a charger it has a wider pulley and timing belt than NA 8V's as it has to drive twin cams, so I'd imagine the forces are similar.

Even if the pulley turned again on the crank it's not an interference engine anyway the 8v G60 is it? Considering the work of taking the crank out I'd say it's worth a shot.

I marked the new bolt head and pulley against each other so I can see easily if either starts to move, no problems though and I rag my engine to 7200rpm regularly and it rolling-roaded at nearly 180bhp.

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Get a new crank pulley, drill it to accecpt a couple of hardend roll pins. Fit the pulley up to the crank and drill through to pin it in position. Use some thread lock and a dx crank bolt done up nice and tight and you shouldnt have any problems. I have done a couple like that and they are still going ok.

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Hi all,

 

Just a quick update, I replaced the Crankpulley with a new VAG one (new pulley includes the keyway!) so she is back on the road and legal as it passed the MOt yesterday! Cheers for all the help and advice am a happy G60 owner again :-)

 

P.s can anyone recommend anywhere round Southampton I can get it tunned? She runs ok but floor it and it starts juddering when you get to 4000 rpm, have heard good things about Autotechnique but last time I spoke to them they had a 4 week wait... Could do with getting done this weekend really, anyone got any recommendations?

 

Cheers

 

Dan

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