timing belt questions on 3.4

[loveourtoys]

:shootme: You guys are probably starting to get tired of my posts and I'm starting to feel like quite an idiot, but I have a few more questions. I started pulling off the top half of the motor today to do the head gasket and I ran into a wierd thing. I just replaced the timing belt and w/p and radiator about 2 months ago and I remember lining up on the belt with the marks. In fact I remember pulling it off and redoing it because I didn't like the way it lined up the first time! I've done many timing belts, and I really feel like I know what i am doing, but...I go to line up the marks to pull the belt off again, and I can't get them to line up! The first time the mark on the cams were directly opposite the marks on the belt when I lined them up on top. O.K. so I figure rotate again, well now everything moves one tooth to the right. I repeated this procedure 4 more time and each time the mark on the cam moves one more tooth closer, but there are a heck of a lot of teeth on half a cam. I can't imagine that I am supposed to spend 2-3 hours turning the crank shaft bolt until the belt lines up again. Any ideas what could be going on? Also my truck ran great until I did the timing belt/water pump/radiator change. Right from the get go it didn't want to start. After about 1-2 minutes of trying it finally fired. Then it ran great, but that was the first time I noticed the white smoke coming from the tail pipe. I thought that maybe I just didn't notice before because it wasn't inside a building when I was starting it, but now I am beginning to wonder???

[8802]

Maybe I misunderstood you, but, way dont you turn the motor in the opposite way.

[loveourtoys]

either way I'd have to make the belt go half way around the cam to line up, one tooth at a time, for every complete revolution of the belt? It just doesn't sound right, I thought the idea of timing marks was to keep the belt in the same place? If it changes every time you turn the belt, what was the point of ling it up?

[loveourtoys]

Well, it looks like they sold us the wrong belt at the dealer. Never even thought to check the numbers on it to see if they matched, just assumed they knew what they were doing. The belt must stay in the grooves for so long then it skips one, is what I'm guessing. I'm sure they won't do anything about it, I guess I should have been smart enough to check it against the old one expensive lesson learned.

[loveourtoys]

The dealer claims that the belt they gave us is right. They said if it wasn't it wouldn't have fit on because they are really different in size. They also said that it could take 10,000 revolutions of the motor before the marks ever line up again and that is normal. Any opinions?

[snorkleman]

10,000 revs until it lines up again? uh...so then after another 10,000 revs does it not line up again? hmmm

Getting the marks lined up right can be a real pain. It is time consuming if you have never done it before but here is what works for me. On the 3.4L I start with the right side cam (when facing the engine). I line the cam up with the groove as best as possible (might be a hair ahead). I line up the left cam and make sure the crank sprocket is TDC. Once everything is set, I lay the timing belt on the right side cam with the mark where it should be at the groove. Then I thread it through the crank sprocket and pulley making sure to try and get it tight.

You want the slack to end up on the left where the tensioner goes, so when you put it on the left cam there is no slack between the top cams. The key is the tensioner. Make sure the tensioner is out (or the keeper pin is in) when putting the belt back on. Once it is lined up, pull the keeper pin on the tensioner. That should take up the slack. Now rotate the crank two full turns and see how it ends up. If the left cam comes up short of the groove, then you are a tooth off. Try again.

On one 3.4 I noticed I had to put the left cam a hair to the left of the groove to fit the belt correctly. When you rotate the crank you want to make sure there is no slack between the cams or the crank on the right side. The tensioner is what takes up the slack on the left side.

I hope this helps. Just remember there should be no slack between the cams or the cams and crank other than where the tensioner is.