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Author Topic: Eating timing belts  (Read 850 times)

Reply #15January 06, 2019, 09:00:36 pm

Ibuprofen

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Re: Eating timing belts
« Reply #15 on: January 06, 2019, 09:00:36 pm »
Thanks for measuring that, I'm getting 16-17mm:




Looks like it's time to track down the ALH hub/sprocket. Thanks.

Reply #16January 07, 2019, 12:36:37 am

libbydiesel

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Re: Eating timing belts
« Reply #16 on: January 07, 2019, 12:36:37 am »
That also means that you will need to adjust the belt tracking by rotating the injection pump mounting bracket.  You will need to rotate the sprocket side of the pump DOWN and the delivery valve side of the pump UP.  Pump will need to be removed to do that.

I want to reiterate what I said earlier.  The belt should *NOT* rub on the back of the crank pulley.  The best test for that, IMO, is to remove the crank pulley and lower timing cover and then run the crank through a bunch of revolutions by hand to see if the belt tracks off the front of the crank sprocket at all.  If it does, you need to adjust the injection pump bracket in order to get it to track closer to the engine. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #17January 07, 2019, 02:27:27 am

Ibuprofen

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Re: Eating timing belts
« Reply #17 on: January 07, 2019, 02:27:27 am »
I think I am understanding correctly, the idea being to change the angle of the IP sprocket so the lower half points more towards the engine, which should help correct the belt position on the intermediate shaft pulley?

I am already trying to track down the ALH hub and sprocket assuming that is the better long term solution. I still haven't pulled off the lower cover as it's been typically rainy here in the PNW but will do so soon. When you say crank pulley, you are referring to the harmonic balancer?


Thanks

Reply #18January 07, 2019, 11:34:33 am

libbydiesel

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Re: Eating timing belts
« Reply #18 on: January 07, 2019, 11:34:33 am »
Yes, when I say crank pulley I am referring to the harmonic balancer.  The belt should not be riding up against the back of it.  It is very common that it does due to bad belt tracking. 

The injection pump bracket has some play between the three mounting bolts and the holes they go through in the bracket.  Sprocket side DOWN injection line side UP makes the belt track closer to the engine.  If you don't have enough play in the bracket holes to get the belt to track so it doesn't rub on the back of the crank pulley, then you will need to enlarge those holes in the pump bracket so you can adjust the tracking further. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #19January 16, 2019, 04:02:50 am

Ibuprofen

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Re: Eating timing belts
« Reply #19 on: January 16, 2019, 04:02:50 am »
Are you referring to the holes at the IP/bracket interface or the bracket/block interface? Sounds like the IP/bracket interface.

I bought an ALH IP sprocket and compared with the current one I have, they're nearly identical spacing from the edge of the injection pump. The ALH sprocket is maybe half a mm closer to the pump, not much at all. The IP hub was ALH the whole time, forgot that I'd already swapped that on there and compared with a spare I have it appears to be the same size/width/etc.

I am thinking I can either:

1. Slot the holes in the bottom of the injection pump bracket such that it can slide further towards the flywheel side of the engine, concern being the bracket won't stay-put long term.
2. Add some sort of spacer(s)/washers between the injection pump body and the injection pump bracket, concern being this is too janky or not enough surface area connecting the two components. Writing this I recall having a sheet of stainless that I should measure the thickness of.
3. Machine the IP hub so it's thinner.

I am not too keen on setting anything at an unnatural angle by shimming one side of it.

Eyeballing the injection pump with everything mounted, regardless of sprocket, it really does seem like the whole assembly is too far to the pulley side of the engine, strange.
« Last Edit: January 16, 2019, 04:23:43 am by Ibuprofen »

Reply #20January 16, 2019, 12:35:40 pm

libbydiesel

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Re: Eating timing belts
« Reply #20 on: January 16, 2019, 12:35:40 pm »
Are you referring to the holes at the IP/bracket interface
No.

 
Quote
or the bracket/block interface?
Yes. 
Quote
Sounds like the IP/bracket interface.
  Nope.

Quote
I am thinking I can either:

1. Slot the holes in the bottom of the injection pump bracket such that it can slide further towards the flywheel side of the engine, concern being the bracket won't stay-put long term.
No, no, no...  Reread my posts.  You do *not* want the bracket to move toward the flywheel.  That will only change where the belt rides on the IP sprocket which is not the source of the belt wear.  You need the belt to track toward the engine at the CRANKSHAFT.  You need to ROTATE the bracket relative to the mounting surface of the block.  The sprocket side needs to go DOWN and the injection line side of the pump needs to move UP.  I'm not sure how to make that more clear. 

Quote
2. Add some sort of spacer(s)/washers between the injection pump body and the injection pump bracket, concern being this is too janky or not enough surface area connecting the two components. Writing this I recall having a sheet of stainless that I should measure the thickness of.
Nope.  Again that might could change the position of the belt on the IP sprocket but do nothing to address the actual issue that is chewing up the belt.

Quote
3. Machine the IP hub so it's thinner.
Same thing.  It won't help prevent the actual issue.

To be clear VW actually released a service bulletin specifically stating the procedure I have outlined for adjusting belt tracking.  Bad belt tracking so the belt rides off the front of the crankshaft and wears against the crank  pulley is a COMMON and well-known problem, and the cure is also well-known.  The belt tracking needs to be adjusted as I've outlined EVERY TIME the injection pump bracket is removed from the block or any time the tracking is off. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #21January 16, 2019, 01:37:40 pm

Reply #22January 16, 2019, 02:37:11 pm

libbydiesel

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Re: Eating timing belts
« Reply #22 on: January 16, 2019, 02:37:11 pm »
You push DOWN on A and lift UP on B to get the belt to track closer to the engine.  I've adjusted belt tracking in this manner on ~10 1.6, 1.6TD, 1.9TD and 1.9TDI engines.  It certainly works.  It's a little bit weird, to have described exactly how to adjust the tracking multiple times and to have you come back and proclaim your disbelief that the adjustment in the manner described can work.  Great, use shims if you want.  I'm done. 
Use, abuse or ignorance of any information is at your own risk, confirmation or refutation is your own responsibility, no further 'proof' will be given, take it or leave it, YMMV,terms subject to change without notice, avoid contact with eyes or skin, contents known to cause cancer in California

Reply #23January 16, 2019, 02:56:04 pm

Ibuprofen

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Re: Eating timing belts
« Reply #23 on: January 16, 2019, 02:56:04 pm »
Yeah, I get it. I think my confusion was due to looking at the engine at 50 degrees, down and up being relative terms.

Thanks for the help.
« Last Edit: January 16, 2019, 03:10:07 pm by Ibuprofen »

 

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