For the people who hate belt changes because of possibly skipping a tooth, i have a sorta foolproof way an old mechanic taught me.
He used to use fast drying paint, i use a paint marker.
1. Paint 2 belt teeth on the camshaft sprocket, and extend onto the sprocket.
On twin cams on the second sprocket the belt gets 3 teeth painted.
2. Paint 1 tooth on the crankshaft and extend the line onto the sproket.
3. Let the paint dry while having a cup of coffee.
4. Loosen tensioner and remove belt.
5. Put old belt back to back with new belt and transfer paint marks to new belt.
Hold both belts back to back with 2 fingers while pulling it sideways,
while holding the belts togheter , back to back between your other fingers,
allowing the belt to slip through, be carefull to keep the teeth alligned, the
old belt can be a bit stretched versus the old one.
There's not much stretch in these things, but enough to go of a tooth on
the timing if you don't watch it
Going around a few times the marks SHOULD continue to line up.
If not either your new marks are off, or they gave you the wrong belt.
Which is the reason he used to do it this way, he got sent a wrong belt
on a few occasions.
And if its just 1 tooth longer, would you notice ?
6. If everything keeps lining up transfer the paint on the new belt to the other
side of the teeth and let it dry for a minute or 2.
7. Mount the belt and new tensioner asuring yourself al your paint marks are
lining up. Spring clamps and bulldog paper clips are awesome tools for
holding a belt in place while you work it over the other sprockets without
it shifting a tooth or 2 on you.
They are also dirt cheap, and if you have ever done a timing belt on a
Subaru boxer engine, you know which dealer apprentice ship i got this
trick from.
8. If all your marks stil line up, put the belt on the correct tension, and check
again if everything stil lines up. If so, and you followed each step carefully,
taking your time, you have just swapped belts and the timing is still perfect.
9. If all lines up perfectly, but your still sweating, put a socket on the crank-
shaft bolt, take out your favorite ratchet, and turn the engine over a few
times by hand.
You should feel the resistance of the compression in the cilinders,
(or take out al the spark plugs to really feel any resistance)
What you should NOT feel or hear is "KLOINK" or any real "binding"
or resistance greater than the compression of the engine.
If it ïs impossible to turn it over by hand at a certain point you :
A: Didn't eat you're Weatabix this morning.
B: It's binding because the timing is of, recheck your marks.
NOTE: while turning the engine your paint marks will "migrate".
This method is usefull on a lot of cars, especially where the timing marks are molded on the plastic belt guards, but have been broken off, or rubbed away by for instance a frayed multigrove belt.
Or if the entire piece of guard with the mark on it is missing
Leaving you without the correct marks to set / check the belt timing.
I have also found that on some vehicles the timing marks when put exactly right,
The belt teeth land ontop of the sprocket teeth instead of in the gaps, leaving you to wonder whether you should go half a tooth forward or back
Sometimes this is caused by the "play" in the mounting for the rear halve of the guard, which allowes for slight adjustment up and down of the cover.
Sometimes even the cast in the block ones are off a bit, like on my daihatshu.
Also, you've checked to see whether the idiot behind the parts counter did in fact
give you the correct belt for your make and model engine.
When done correctly, everything is as it was before but with a new belt and tensioner, and please, get some springclamps or buldogg paperclips to help you.
Those things are dirt cheap and have SO many uses around cars.
It will take away a lot of stress if you were not born with 3 arms and 15 fingers.
I hope this helps some of you guys, sorry for the long post, just hoping to help some of you.
Thank you for the very good technique! And the time it took to write it all up. I will do it this way from now on.
, but not so explosive)