1/2 a tooth off on timing belt?!? No adjusting helps!

[GSXRolla]

Ok, I've readjusted this damn timing belt like 4 time tonight, and I can't figure out what the hell is going on...!

Ok, I follow all the instructions on the vfaq and even my chilton's manual regarding the timing belt change. EVERYTHING goes smooth RIGHT UP until it comes to tensioning the belt. What I find is that the exhaust cam always seems to end up half a tooth off... I know this has been discussed a hundred times, but I've really tried to readjust this thing over and over, and it's just not having it!

What I am finding is that I'm getting a TINY TINY bit of slack between the crankgear and oil pump gear (no balance shafts, so not concerned with the oil pump marks... but I do it anyway...). When I rotate the belt after I've pulled the pin on the tensioner, it seems to pull that exhaust cam off 1/2 a tooth or so. I'm having MAJOR sounds coming from my engine when it's like this, it's a replacement shortblock from someone else, and first and foremost, I want to get this timing DEAD ON so that I can either feel good about the noise going away, or move on to another diagnosis.

At this time I don't need help diagnosing the noise (I think the pistons are gently tapping the valves with the messed up timing). I just want to know how to get this timing on. The only thing I can think of is that I may have stretched the new belt by applying too much tension to the tensioner pulley before pulling the pin on the hydraulic tensioner. You see, the first time I did the t-belt, it was while the engine was out of the car. I did it, and never bothered checking it again. Well now it's in the car, and I'm having a bi*** of a time gettings past this.

Thanks for the help people! I do appreciate it.

 

[BlackViper]

I had a problem with the timing belt where when I got it tightened down the cam gears would be off slightly. If thats whats happening to you too, then you need to off set them before you tighten it back up. My friend helped me with it so I can't go into detail. Let me see if I can talk to him about it tonight and I'll post again later.



BlackViper

 

[GSXRolla]

Thanks man. That would be of great help. What is going on is... when I apply tention to the tensioner pulley, it will tension the belt on the left side of the engine, and the belt still has a little bit of slack between the crank gear and oil pump gear. And if I tighten up the slack between the oil pump and the crank gear, I it throws either the oil pump off or the crank gear off, which is why my cam gears are appearing to be off by 1/2 a tooth.

AFTER it's tensioned, my crank gear is about 1/2 a tooth clockwise farther than the timing mark when the cam gears line up. It's like the slack in between the crank and oil pump gears are throwing things off!

Thanks in advance for helpin me out BTW.

 

[BlackViper]

Ok so I talked to my friend a little bit ago and he was saying that you purposely have to make the cams gears not align before you tension the belt up. I believe the cam gear closest to the tensioner has to be below the other gear so that it gets pulled up counter-clockwise. Let me know I didn't explain it enough. Good Luck.



BlackViper

 

[Defiant]

Originally posted by GSXRolla
(I think the pistons are gently tapping the valves with the messed up timing).

Let's hope not. That would be gently _bending_ the valves. Nothing in there is just floating around "loose".

 

[ArticNemesis]

yea.. the valves won't "gently" tap the pistons at 700RPM's.. Try zip tieing the cam sprockets together (worked for me) until you have the timing belt on.. If you stretched the belt, you wouldn't happen to be using a different timing belt than the OEM geniune Mitsu belt would you.?