This is more hypothetical at this point, but as I am going to change my water pump soon, it may become more real...

What happens if the camshaft and the crankshaft get 'out of sync'? Now I don't mean while the engine is running -- if that's the case you get bent valves and/or busted pistons. I mean when the engine's apart and either the belt is off of if the crankshaft or camshaft slip the belt. How do you get things back to TDC to line them back up again?

If the crankshaft pulley is still on, no problem getting the pistons back to TDC. But what happens if the pulley's been taken off? Does the pulley only go on the crankshaft one way?

And what about the camshaft? How do you make sure the valves are in the right position for #1 TDC? And again, what happens if you pull off the camshaft sprocket?

This stuff is fascinating... unfortunately I don't know what I'm doing!!! Yet! Thanks for you help.

 

my suggiostion for you is to get yourself a good manual. it'll tell you everything you need to know.

 

I second that. Purchase a helms manual and it will give you all the info you need. I know that it helped me out a lot when I first started tinkering with my car.

 

Get a manual, start to read, they do a good job of explaining what has to happen. But to answer some of your questions in short:

Both the camshaft gears and the crank pulley fit on only one way. They both use a "key hole" system that only allows the gears to fit on one way, the right way.

When the crank pulley, t-belt cover and the timing belt are off, there is are two markings that line up to let you know that you are at TDC #1(crank). The markings are on the block and the crank timing belt gear. When they line up you have it right. Just as the cam gears are. In SOHC the horizontal lines are paralell with the block deck, and the third mark lines up with the t-belt cover mark, and the word "UP" is readable, and up. In DOHC the horizontal lines need to make a straight line across the gears, and you need to be able to read the "UP" markings, just as the sohc gear. It is all very simple, once you see it once, it is second nature. When you get a timing belt(which you should replace when you do the pump) it comes with good instructions on EXACTLY what to do, and where the markings are. They also explain the procedure to tensioning the belt, something you will have to read yourself. #1 rule, Do not be intimidated by timing, it will either work, or you know it won't work, get the manual, they get paid to explain this to you, so it may be easier to understand. ..................IN SHORT

 

A Helm's manual, you say? I've got a Hayne's manual and I can't find an explanation for all of this. In one place it says to line the crankshaft pulley marks up with the mark on the timing belt cover, but that doesn't tell me what happens once I remove the pulley. In another place it says to put the camshaft sprocket back on such that some hole is in the 12 o'clock position and the line marks are parallel to the head seal. Fine and dandy, but is that enough to ensure that the valves are in the right place? I just don't know.

I think I'll head to the library and look at the Helm's manual -- and just keep reading what the good people here are saying.

Thanks.

 

Ah! Thanks for the info. My manual mentions the markings on the sprocket and pulley but never spelled it out that they can only go on one way. I assumed this, but wanted to make sure!

As for changing the belt, it was just recently changed (by a garage) -- it broke one day while I was on the freeway. Bent some valves The thing that really sucked was that I still had 15K left on the belt that broke -- it went early! But I'll inspect this one when I get it off and replace it if it looks even a little worn!

Thanks again.

Oh, maybe you can answer another question: the three timing marks on the pulley (after the TDC mark). What exactly do the mean? What degrees of timing are they? Manual doesn't say and the VECI label just says my timing should be 10 +/- 2 degrees. Does that mean the marks are 8, 10, and 12 degrees?