Cam timing help
08-26-2002, 07:23 PM
#1
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Cam timing help
Hi all,
I am stripping the front of my engine, an '84 928S M28/22 to replace the cam belt and overhaul the tensioner. Tried to line up all the timing marks but when the cam marks are lined up the marks on the vibration damper are nowhere to be seen. I'm pretty sure the engine is at TDC on No. 1 because the distributor rotor arms are also pointing correctly at their marks. The marks on my vibration damper don't match any of the pictures in the manual and appear "backwards", see picture. Is it possible the vibration damper is on backwards ?
Thanks again for any ideas / suggestions
I am stripping the front of my engine, an '84 928S M28/22 to replace the cam belt and overhaul the tensioner. Tried to line up all the timing marks but when the cam marks are lined up the marks on the vibration damper are nowhere to be seen. I'm pretty sure the engine is at TDC on No. 1 because the distributor rotor arms are also pointing correctly at their marks. The marks on my vibration damper don't match any of the pictures in the manual and appear "backwards", see picture. Is it possible the vibration damper is on backwards ?
Thanks again for any ideas / suggestions
08-26-2002, 09:11 PM
#3
Burning Brakes
I just checked my belt tension on Sunday and I would have to agree. It does look like its on backwards.
Not sure how much work is involved to correct it but it sure would be a good idea since your in there already......
Not sure how much work is involved to correct it but it sure would be a good idea since your in there already......
08-26-2002, 10:57 PM
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It your '84 Euro motor is similar to my '82 Euro motor with regards to the vibration damper (PET does show different part numbers) the picture you show appears to have the vibration damper on backwards. The 0|T mark does not line up since the key-way is offset from TDC. To fix this you will need a flywheel lock, large metric socket to grab onto the front crank bolt, a bowl of wheaties (maybe 2), and some elbow grease. I think I also used a gear puller to pursuade the vibration damper off the crank. Hope this helps!
08-26-2002, 11:31 PM
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With the crank pulley mark, at 0/T (TDC), the #1 piston should be at TDC on compression stroke. The easiest way to tell is the rotor should be pointing (ready to fire) at the #1 cylinder spark plug wire and the marks on the cam sprockets should line up with the marks on the flange.
Remove the #1 spark plug, find a round piece of wood about 1\4” in diameter 15” long (home depot) while holding the wood insert it in the spark plug hole, have someone turn the crank shaft by hand C wise only (with a wrench) you will feel the piston pushing the wood up as soon as you feel the wood start to move down stop turning the crank. With a flashlight look in the cylinder you should see the top of the piston. The O\T on the crank pulley should line up or be very close to the red pointer.
The distributor rotor should be pointing (ready to fire) at the #1 cylinder spark plug wire and the marks on the cam sprockets should line up with the marks on the flange. If you make any changes always turn the engine over by hand only, making sure the valves do not hit.
If the piston is at TDC and the rotor is pointing or just about to point at the #1 cylinder spark plug wire the crank should be at 0/T at the pointer if not turn the crank pully around.
Post what you find
Is this motor running?
do not start this motor until it is right.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
Remove the #1 spark plug, find a round piece of wood about 1\4” in diameter 15” long (home depot) while holding the wood insert it in the spark plug hole, have someone turn the crank shaft by hand C wise only (with a wrench) you will feel the piston pushing the wood up as soon as you feel the wood start to move down stop turning the crank. With a flashlight look in the cylinder you should see the top of the piston. The O\T on the crank pulley should line up or be very close to the red pointer.
The distributor rotor should be pointing (ready to fire) at the #1 cylinder spark plug wire and the marks on the cam sprockets should line up with the marks on the flange. If you make any changes always turn the engine over by hand only, making sure the valves do not hit.
If the piston is at TDC and the rotor is pointing or just about to point at the #1 cylinder spark plug wire the crank should be at 0/T at the pointer if not turn the crank pully around.
Post what you find
Is this motor running?
do not start this motor until it is right.
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
08-27-2002, 09:32 AM
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Hi all,
Thanks guys - yes I'm now convinced the pulley is round the wrong way, God knows which bright spark did that ! Potential booby-trap. I've just purchased a flywheel holding tool and I'm eating my big breakfast before attempting to undo the pulley bolt which I can see from the specs may be more than finger tight.
Cheers for your answers.
Thanks guys - yes I'm now convinced the pulley is round the wrong way, God knows which bright spark did that ! Potential booby-trap. I've just purchased a flywheel holding tool and I'm eating my big breakfast before attempting to undo the pulley bolt which I can see from the specs may be more than finger tight.
Cheers for your answers.
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08-27-2002, 02:07 PM
#8
Burning Brakes
BTW - Make sure you do not attempt to rotate the crank counter-clockwise to align TDC. Clockwise movement only. If you miss your mark, come around again - don't back up......
Cheers
Cheers
