Finding TDC with broken timing belt

[ChicagoRangerDanger]

OK, so I've got my timing belt cover off and the belt is shredded and broken (belt is actually snapped).

When I move the crank pulley to find the TDC mark, the other gears do not move. I'm supposing the reason is that the timing belt broke and so it does not move the other gears as the pulley moves.

So, how to I know everything is lined up correctly? Can I independently line up the triangles, diamond and tdc and then put the belt on?

How do I do this?

Thanks!

 

[adsm08]

You line up the triangles etc.

Read this: http://therangerstation.com/Magazine/Summer2010/4cyl_timing_belt.shtml

 

[ChicagoRangerDanger]

Hey adsm08, thanks for your continued help.

I get the part about lining up the triangles and diamonds.

But with the belt broken, it doesn't appear that the the gears will all spin together. Does that make sense?

I guess I'm assuming that I can't move each of them independently and just line them up. I thought they needed to move together to make sure the gears are lined up properly but spinning them until all the triangles, diamonds and the TC mark all match.

Can you move them independently? And if not, how do I know that they're in proper alignment?

 

[Mark_88]

Yes, you can move them independently...the cam has one revolution per two crank revolutions so you just have to line up the mark...same with the oil pump gear...spins one time for every two crank revolutions...

So...the important thing is to make sure the crank is at TDC on the compression stroke...

 

[RonD]

Yes ^^^

"Timing Belt" it a good description of what it is there for, it "times" the crank, cam, and oil pump/Distributor gears.

Their only connection is the "timing belt", so they can be turned to any position when belt is off, preferably to their respective "timing marks" so the belt can be install and get them all "timed" to eachother

 

[adsm08]

But with the belt broken, it doesn't appear that the the gears will all spin together. Does that make sense?

Of course that makes sense. The belt is what makes them move together, so if it is broken or off they can't move together.

I guess I'm assuming that I can't move each of them independently and just line them up.

Why do you think that?

Can you move them independently? And if not, how do I know that they're in proper alignment?

Sure you can. Moving them one by one to the timing marks is how you know they are in proper alignment. One a lot of newer engines that can be dangerous, but since your belt broke with the engine running the crank has already moved by itself.


In regards to Ron's comment about making sure you are on the compression stroke, the cam position is what determines intake/compression/power/exhaust stroke, so if the cam isn't moving you aren't on any stroke, per se. Just get cylinder one to TDC, or where ever the mark for the crank is, then get the cam lined up with it's mark. That will make you be on compression.

 

[Mark_88]

In regards to Ron's comment about making sure you are on the compression stroke, the cam position is what determines intake/compression/power/exhaust stroke, so if the cam isn't moving you aren't on any stroke, per se. Just get cylinder one to TDC, or where ever the mark for the crank is, then get the cam lined up with it's mark. That will make you be on compression.

After all these years of doing the timing on my 2.3 it never really occurred to me that the cam HAD to be set first or there would be no compression that could be felt with a thumb over the plug hole...but for some strange reason that wasn't related to a cognitive recognition of that fact, I always set the cam first before checking for the compression stroke by putting my thumb over the plug hole and cranking the engine by hand...

This, of course, is proof that God exists and that Angels are here to help us...if it was not for my invisible friends I would never have set that timing without checking in with my earth Angels on TRS...

I am going to try to film this and make one of those tear jerking short videos to post that shows how God loves us...