What size are the td5 timing mark threads ?.

[Stuck]

I'm in the process of replacing the head gasket, hopefully not the head fingers crossed on my td5. I've been following Psimpson7's excellent tutorial as per "The Good Oil" but I've had a stuff up and I still can't believe I've done something as stupid as this. I wound the crank over by hand until I got the two coloured links at the top, cable tied them to the sprocket then proceeded to remove the chain tensioner after which I remembered that those links need to line up with a mark on the sprocket. Without thinking, I cut the cable tie and proceeded to turn the motor in an anti clockwise direction (without refitting tensioner but still with the allen headed guide thingy on the other side in place) and had only turned it maybe 15 degrees when I heard a metallic clunk (like tapping the timing case with a spanner) but felt nothing strange through the breaker bar. Subsequently, I can't find a bolt to fit the alignment hole in the head and for my own peace of mind I'd like to check the timing to make sure nothing's slipped before I go any further. If anyone can shed some light on what that clunk may have been or give me the thread sizes for the timing marks in the head and the bell housing (it's an auto) it would be much appreciated.

Thanks in advance.

[discorevy]

If you had the tensioner out and were turning anti clockwise the chain could well have bunched between the timing cover oil collection lip ( cast with timing cover ) and sprocket , possibly breaking the lip. you'll need a borescope to confirm.
the other possibility is you have the cam timing wrong and it's a piston tipping a valve.
If it's the latter ,to check , fit the tensioner and turn clockwise until you get the cam lined up with the cutout making sure it's not touching a valve, then get underneath and make sure the cutout in the flywheel lines up ( I can't remember the size as I use the locking tools but 6mm for cam cutout and 8mm for crank drill bits come to mind ) line up the 8mm drill bit so it is in the centre of the hole and forget the coloured links as the are only used when replacing the chain and will only come around every x amount of rotations.
If the crank / cam cutouts don't line up get back on here and I will tell you how to line everything up without removing the cam/head

[Davetd5]

Yes discorevy is correct (and he knows what he's talking about, believe me!), 6mm drill bit for the cam cut out and 8mm for the crank cutout.
The I've been adjusting my cam timing tonight and I made a crank locking tool using a male air line fitting, like the one that screws into a rattle gun.
I cut the end off leaving the thread which is probably 1/2 inch thread. I drilled the centre bore to 8mm and screwed it in the bell housing and slid the 8mm drill in to lock the crank.

[Stuck]

Thanks for the replies. The bit that threw me was in the tutorial it said to use a bolt to lock the cam and I presumed it wound in as opposed to being just a pin. The clunk wasn't very loud and I felt nothing through the breaker bar which I had stuff all pressure on. It sounded more like something had dropped. On the positive, the marks still line up as I thought maybe the chain had somehow skipped a tooth.