# Crank Pulley Wobble



## millerspcrepair (Mar 16, 2009)

I got a 98 vw gti 2.0 8v and opened my hood and noticed the crank pully wobbling. So i changed the pulley with a known good one and still has the wobble. I was just wondering if anyone else had this problem with the crank sprocket or am i looking at a bent crank.


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## greyhare (Dec 24, 2003)

I doubt the crank is bent. Check that the pulley is indexed correctly, the 4 bolts are properly torqued, the center bolt is not loose or broken. If the center bolt is loose or broken you need to inspect the key on the sprocket and crank, replace the bolt and check timing. The center bolt is torque to yield and must be replaced if it is removed.


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## millerspcrepair (Mar 16, 2009)

The Pulley is def torqued down to specs and the center crank sprocket bolt is tight. I am just trying to figure what cause these to wobble.


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## Glegor (Mar 31, 2008)

its the crank sprocket (the one that drives the timing belt)

they are just like an AAZ crank nose, and those fail all the time..

it needs a new crank sprocket and crank bolt. and possibly the keyway in the crank shaft repaired.

:beer:


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## FL 2.0L (Aug 1, 2002)

Check the key on the back of the sprocket, as noted above. Also, there are two pulleys bolted to the crank sprocket. Sometimes the rubber damper material between them deteriorates, but I guess you have eliminated that.


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## greyhare (Dec 24, 2003)

See the bump between two of the bolt holes? The other pulleys will have a hole that lines up with the bump to index them.

You can see the key the others mentioned on the back of the sprocket.


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## millerspcrepair (Mar 16, 2009)

Well I went and ordered a new sprocket and bolt it should be here tomorrow or Tuesday ill keep you all updated.


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## millerspcrepair (Mar 16, 2009)

OK got the Crank sprocket & bolt changed its got a slight wobble(no where near as bad as before) at idle but as soon as i give it a little throttle the wobble goes away. Any Suggestions


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## FL 2.0L (Aug 1, 2002)

How bad was the notch in the nose of the crank?


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## Glegor (Mar 31, 2008)

greyhare said:


> See the bump between two of the bolt holes? The other pulleys will have a hole that lines up with the bump to index them.
> 
> You can see the key the others mentioned on the back of the sprocket.


the 4 bolt holes are drilled so you cant put the pullies on wrong, and have all 4 bolt holes line up.. so rule that one out.

and did the notch in the end of the crank look chewed up at all? did the crank nose look worn at all..

sometimes these things get so bad that the nose of the crank has to be re-machined.


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## millerspcrepair (Mar 16, 2009)

The crank nose looks in pretty good shape teh keyway on the nose has a little wear but nothing major.


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## SBPCR (Jul 8, 2012)

*Same issue, with a twist...*

I noticed the same issue after having a 'friend' replace my head gasket about a year ago (after he mis-diagnosed an overheating problem (I don't know what he was thinking), then losing a serp belt on the freeway last month. Mine is a 1996 Golf GTI 2.0L.

At any rate, after I replaced the belt and drove it for a while, I noticed signs of wear on the edge of the serp belt (toward the block) and it was then I noticed the wobble of the harmonic balancer.

I tore into it today, since I'm still having overheating problems and am changing the thermostadt, water pump and radiator anyway.

Now here's the twist: 

The timing belt is showing alot of wear on the edge away from the block and the harmonic balancer aluminum hub has been worn by the timing belt - to the point where the timing belt teeth are mirrored on the harmonic balancer hub surface. ic:http://www.sbpcr.com/photos/GTI.Harmonic.Balancer.hub.wear.caused.by.timing.belt.jpg

And, yes, the key in the balancer hub is damaged and only half there as if it were chipped and or crushed..ic:http://www.sbpcr.com/photos/GTI.Crank.Sproket.key.damage.jpg

The crank nose looks ok.ic:http://www.sbpcr.com/photos/GTI.Crank.nose.jpg

With the balancer off, the sproket carefully positioned and torqued and a new timing belt on, when I crank the engine to ensure the timing belt centers itself, it does just fine on the cam sproket, distributor sproket and the manual tensioner, but I can look down at the crank sproket and see that 1/8th of an inch of timimg belt is not even on the sproket, and has been riding against the aluminum hub of the harmonic balancer causing the above pictured damage. ic:http://www.sbpcr.com/photos/GTI.Timing.Belt.position.on.Sproket.jpg

Now, either I have a crankshaft that has shifted toward the tranny end by 1/8th inch, or I do not have the correct timing sproket on the crank.

I drove the car with no serpentine or timing belt issues for over 10 years prior to all this. I've looked at all I can find on the web as far as assembly and apparently there are no left-out 1/8th inch spacers in the equation.

Any ideas? Your help is greatly appreciated.


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