Timing Belt Sprocket

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Apr 24, 2006 | 05:27 PM

ajaudi

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Timing Belt Sprocket

Hi - I'm new to the forum. Hoping someone can help me. I've been changing the timing belt on my 2.7T as per the Bentley procedures. The crankshaft locking pin has been installed. I've replaced the thermostat and water pump. I've installed the sprocket locking tool and backed off the bolts securing the sprockets to the cam shafts. As I was using the sprocket puller to pull the sprocket off, the torque that I apply to tighten the puller has caused the shaft (not just the sprocket, but the whole shaft) to rotate by about 1/5 of a revolution. My questions are as follows: 1) should this have happened with the crankshaft locking pin in place, 2) how do I reallign the shaft - is it OK to apply torque to rotate it (it does not rotate easily), 3) The shaft moved 1/5 of a turn clockwise (as you face the engine) - should I complete the revoultion clockwise, or turn back counterclockwise, 4) should I leave the cranksaft locked to do this.

Any advice greatly appreciated.

Thanks,

ajaudi

2000 2.7T Quattro

Apr 24, 2006 | 06:15 PM

4Driver4

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No worries.

Leave the crank locked.
The valve springs exert a lot of force on the cams, and it is not uncommon for the cams to "jump" when the timing belt is removed or when the sprockets are loosened from the cams. It's pretty damn scary when it happens, but the cam won't jump enough on its own hurt anything. No rush on moving it back either - it will probably just jump again. It can stay there until the new belt is installed and you are lining everything up to torque the sprockets back onto the shafts. Use the alignement plate and the locking bar to turn it back if possible.

Kudos to you for taking the time to do it right and set the cam timing.

I strongly (very, very strongly) suggest that you change the cam adjuster seals as part of your service if you aren't doing them already.

Have fun.

Apr 24, 2006 | 08:17 PM

ajaudi

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Re: No worries.

Thanks very much for the help. I used the allignment plate to rotate the camshaft back the 1/5 turn - just needed a bit of force to overcome the valve springs. Like you say, the initial 'jump' was a little unexpected and I didn't want to start forcing things before getting some advice.

Good advice on the cam adjuster seals as well.

Incidentally, I'm changing the timing belt early at 63k miles. Although the consensus seems to be that this is way early for the 2.7T / 2.8, I found a tear / hole in the belt I just removed. I have doubts that this belt would have lasted to 85k.

Cheers,

ajaudi
2000 2.7T Quattro (6 speed)

Apr 25, 2006 | 04:24 AM

Edd W

AudiWorld Super User

Joined: Aug 2002

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From: Warwickshire

I do wonder if belts deterioration is partly age related and not....

necessarily just mileage. I would think also that driving style has a an effect, a lot of short journeys will cause pro-rata more wear then single longer journeys.

I will probably change the belt on my late 2000 2.7 at about 50k. It currently has just on 39kwhich means about this time next year I guess. My wife wants me to look for a C6 avant, probably 2.7 or 3.0 tdi avant quattro but although I think they look superb, I will wait a but longer before going over to an oil burner.

Apr 25, 2006 | 05:10 AM

4Driver4

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That sounds very reasonable.

More starts/stops means more heat cycles which will accelerate the belt's demise. Time plays a big factor too. The belt on my S6 has 30k on it but I will probably do it this Summer since it was last done 6 years ago.