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AAZ timing belt replacement & crank pulley wobble

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thephatmaster View Drop Down
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    Posted: 24 Feb 13 at 22:40
Hi there,

I am about to do my AAZ's timing belt and have researched the procedure in my tech manual (Hayes) and on this forum. I am confident about the job, and have fabricated the camshaft locking and bracing tools. I'll also be fitting a clutched alternator pulley as a preventative measure to preserve my middle-aged (130k miles - 1996) engine's longevity.

I note from this and other forums that the crankshaft keyway on some AAz engines becomes worn causing pulley wobble, which can be fixed by fitting a dowel, or machining the crank nose. There are two things which confuse me though:

Firstly I don't get how to test for wobble during my timing belt replacement, nor how much wobble is "acceptable". Should I:
- Remove the crank pulley and inspect the keyway visually for damage (before refitting it, using a new bolt); or
- Not remove it, and attempt to wobble it by hand, or with a tool to check for play?

Secondly:
- There is a lot of talk of "harmonic balancers" and how they get worn (causing pulley wobble), the pictures I see in my manual show the crank pulley as a small toothed pulley with no additional parts, should I be checking something else?

The reason I worry about pulley wobble is that I recently replaced my power steering belt and observed that the PS belt pulley on the crankshaft wobbled by approx 5mm while running. Fitting a new belt (tensioned correctly) seems to have cured this, and it now runs with no wobble.

I'd be grateful for any assistance on these points.

Steve
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Vanorak
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Post Options Post Options   Thanks (0) Thanks(0)   Quote light Quote  Post ReplyReply Direct Link To This Post Posted: 24 Feb 13 at 23:20
The bit that would wobble is the toothed pulley on the crank you should not undo the 19 mm bolt unless you find you have play in the pulley and there should be no play what so ever
You can sometimes get a wobble in the auxiliary belt pulley ( the one bolted on to the toothed pulley with 4 cap head bolts) as they have a rubber damper in them that can deteriorate over time
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max and caddy View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote max and caddy Quote  Post ReplyReply Direct Link To This Post Posted: 25 Feb 13 at 00:36
I would just whip that 19 bolt out and have a look myself...New bolt and back on if its ok...repair with a "d" pulley if not....forget the dowel method, it's a bodge...best to use the later pulley and mod the crank to suit...I,also fit the pulley with bearing retaining fluid on the crank nose.


Only problem with taking the pulley off is holding the engine still when re fitting the bolt...but a tool can be made fairly quickly.
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thephatmaster View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote thephatmaster Quote  Post ReplyReply Direct Link To This Post Posted: 25 Feb 13 at 22:06
Thanks guys,

I must say I prefer the "not touching it" approach... I've learned that the less I disturb engine parts the less goes wrong.

So is this rubber bit the harmonic balancer everyone is taling about? Guess that I can just get a new rubber bit / aux belt pulley if it's shot?



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Post Options Post Options   Thanks (0) Thanks(0)   Quote thephatmaster Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 13 at 09:19
Also, on the replacement with a "D" pulley... rather than getting the crank machined (and therefore having to remove it) - can it just be filed carefully by hand?
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Vanorak
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Post Options Post Options   Thanks (0) Thanks(0)   Quote light Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 13 at 11:21
Originally posted by thephatmaster thephatmaster wrote:

Also, on the replacement with a "D" pulley... rather than getting the crank machined (and therefore having to remove it) - can it just be filed carefully by hand?
 
No to this one
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Vanorak
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Post Options Post Options   Thanks (0) Thanks(0)   Quote light Quote  Post ReplyReply Direct Link To This Post Posted: 28 Feb 13 at 11:28
Originally posted by thephatmaster thephatmaster wrote:

Thanks guys,

I must say I prefer the "not touching it" approach... I've learned that the less I disturb engine parts the less goes wrong.

So is this rubber bit the harmonic balancer everyone is taling about? Guess that I can just get a new rubber bit / aux belt pulley if it's shot?



The pulley the aux belts run on is basically made of two pieces (inner/outer) the bit that`s bolted to the crank pulley and the bit the aux belts run on the two bits are joined together by rubber this is the bit that can deteriorate over time
 
 
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thephatmaster View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote thephatmaster Quote  Post ReplyReply Direct Link To This Post Posted: 07 Mar 13 at 21:02
Sweet, will call my VW Stealer & email Brickwerks and see if they have the rubber... One last question, which dial gauge adaptor do i need for the AAZ - one of these?
http://www.dieselkontor.de/product_info.php?products_id=1030
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max and caddy View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote max and caddy Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 13 at 09:50
The rubber part is not replaceable, and the pulley alone has been replaced by a kit including a freewheel pulley from vw.

Edited by max and caddy - 10 Mar 13 at 09:53
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thephatmaster View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote thephatmaster Quote  Post ReplyReply Direct Link To This Post Posted: 10 Mar 13 at 10:18
Nice, do you know the pulley kit part number?
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Italjohn View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Italjohn Quote  Post ReplyReply Direct Link To This Post Posted: 14 Mar 22 at 07:28
My solution to the wobbley pulley.

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