YotaX

Yes I have googled, used YotaTechs search (have found lots of great info -- THANKS), even "the search engine of all search engines", and my Chilton / Haynes manuals. but nothing detailed enough to help me solve my problem. and i bet it is really simple. Okay guys here is the run down.

1995 4runner 4x4 3vze 5speed.

Thank to all of yalls Tech Write ups I decided to pull the engine, fix the oil leaks, and swap out all gaskets, especially the Head gaskets. Problem is the new timing belt marks will not stay on it marks after 1, 2 or 3 revolutions. I have taken it off and on, ensuring i have both cam sprockets, and crank marks all lined up on 0* before i start turning. but sure enough after i rotate the timing belt lines start moving back one tooth per revolutions. there aren't any tooth jumping or binding.

I assumed it was the Hydraulic tensioner not applying pressure to the tensioner pulley but i had to use a 6" C clamp and Allen wrench to compress it. So it is doing its job. or maybe not and i just dont know it.

What can be causing my timing belt marks to walk.
If i need to add pics or a video, just let me know. i appreciate anyones input. like i said it probably really simple, and im just not seeing it. thanks for reading

bugs1961

The marks on the belt are only for installation and will be off after the first rotation of the crank. Just make sure the marks on the crank and cam pulleys themselves line up with their corresponding marks (on the backing plate and oil pump behind the pulleys) during installation and again after two complete revolutions of the crank and you are fine.

YotaX

Thanks im glad to hear that the Belt Markings are nothing to be concerned about. BUT i rotated 2 full revolutions forward and 2 revolutions back just to double check the marks all returned to 0*. both the cam sprockets line up with the backing plate but now the crank pulley is lined up at 5* advanced. so its out of sync.

TNRabbit

It is VERY EASY to get an extra tooth in between the two cam pulleys. There should be ZERO play between them (where the upper idler pulley is located). you normally have to cock one cam pulley back half a notch when you install the belt to get them properly aligned.

Wrenchinjoe

Make sure the CS and both cam pulleys are lined up on their timing marks which is TDC. Start routing the timing belt at the CS, then wrap the belt over the driver's side cam pulley, then under the center idler, and then over the passenger cam pulley. Make sure the timing marks all line up still and that there is NO SLACK in the belt as you route the belt. The only slack in the belt should be on the passenger side where the tensioner will take it up. Assuming your marks line up through these steps, then after two rotations you should still be lined up.

Magnusian

Don't forget to bring a flashlight, or you may be eaten by a Grue during this adventure!

scope103

Yes, the marks on the belt are SUPPOSED to move one tooth with each revolution. (In gearing, this is called a "hunting" pattern.) If you have a nick in one pulley, the wear is evenly distributed over each part of the belt. If it lined up each time, that nick would always hit the same spot on the belt, producing uneven wear (and probably making the nick in the pulley worse.)

bugs1961

I have found that as you get to the driver side cam pulley, turn it about 1/2 tooth clockwise and engage the belt there. Then turn the pulley back to it's mark and the belt will be tight. That prevents you from placing the belt on the easiest tooth, which will end up being one tooth off. I then do the same thing to the passenger side and when you turn the pulley back to it's mark the belt will be tight and all the marks should line up. Finish running the belt around the tensioner pulley and, once then tensioner is released, all will be well.

Toyota says in my FSM, "never rotate the crankshaft backwards" so I would skip that step. After the belt is installed, rotate the crank two revolutions clockwise and the marks should line up. When they do, put it all back together and smile!

rainman88

nice, this helps me thats exactly what i am having trouble with.

Beaterboy

I'm 3rnd generation mechanics,but suffering from a slight case of brain damage.
I thought I was going looney,
Not thinking about the simple fact that the gears are not the same size..
Thanks again