How tight should the timing belt be over the cams when I first put it in before tensi

Posted by Spoolin4Ever, Sep 21, 2009
Bolt-on Tech - 4G63 intake, exhaust, intake manifold, ignition, fuel system, cooling, etc.

  1. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    My question is:

    When changing the timing belt, and putting the new belt on over the cam gears, how tight should it be between the gears there? I mean before I tension it.

    It is my understanding it should be medium, basically, lay it over the cam gears and let lay in comfortably, but without exerting any real force or pressure trying to make it tight, because that will occur later. Am I correct?

    Along with the manual, vfaq and this website, a friend is helping me, that has more experience in general automotive. He wanted to make it tight right early on up there. Well then when we got it all together, the intake is advanced 1 tooth (or you could say the crank is CCW one tooth, same difference). The tensioner is set properly.

    My friend says he thinks that is as good as we can get it. I think he is wrong, and the whole reason we are having the problem is because he is trying to pre-tighten the belt up on the cam gears before setting the tension.

    Although if it is too lose, it can jump?

    Please let me know how tight to out it on, and also, how will it feel immediately after setting tensioner, how will it feel after setting, and what about after driving? LOL

    Incidentally, how would being off one tooth advance (clockwise) on the intake side affect it?
    #1
  2. lacroixdp

    lacroixdp Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Aug 3, 2004
    Posts:
    695
    Likes Received:
    2
    Columbia, South_Carolina
    Your friend is incorrect. When set correctly, the sprockets will line up perfectly. Refer to this for the proper way of doing it:

    Timing Belt VFAQ (Timing Belt TSB - ENHANCED)

    Use binder clips to keep the belt on the sprockets during the procedure. There should be very little slack at the top when this is done propely. The timing part kit from Jay's Racing makes this process, and the whole job, quite a bit easier for beginners. I'd strongly recommend investing in the proper tools for the job.
    #2
  3. DSMunknown

    DSMunknown Proven Member

    Classifieds Rating:
    100%
    Joined:
    Sep 16, 2004
    Posts:
    2,950
    Likes Received:
    24
    Worcester, Massachusetts
    Pony spring clamps worked very well for me.
    #3
  4. black_gst

    black_gst Freelancer

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Jun 16, 2008
    Posts:
    1,593
    Likes Received:
    9
    IE, California
    i have run across the 1 tooth off thing when doing a t-belt also... it hapens when you dont the those two marks on the cam gears parallel to the head... they both will be slightly higher and then when you apply tension intake mover down half a tooth and is perfect and exhaust moves up one half a tooth and ends up one tooth off... just try and account for it you will be fine.. and always triple check and everything is dead on(blance shaft, crank pully, oil pump, cams!)
    #4
  5. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    #5
  6. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    Sp how tight should I put it over the cam gears? Can there be some slack at first (between the cam gears) before I set tension? Or will that make it slip off? I WILL clip it, I understand the clips help to gold it.
    #6
  7. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    When you set it around the cam gears, it should be tight. You'll want to put it on loosely at first, then line up your inner cam gear marks (with dowel pins at 12 o'clock). Pull the belt - it should take a bit of effort to get the teeth to fall into place. Then put a binder clip around each cam gear over the belt.
    #7
  8. romeen

    romeen DSM Wiseman

    Classifieds Rating:
    100%
    Joined:
    Jul 12, 2006
    Posts:
    2,434
    Likes Received:
    23
    Vancouver, Washington
    As mentioned, it needs to be tight between the cam gears even before setting tension.

    When you are using your 17mm wrench to rotate the exhaust cam gear CW (to get the marks to line up) rotate it just a little bit (CW) past where the marks line up. Hold it there while you put the belt on and secure it to the exhaust cam gear. When you release the tension on the cam gear it will take out the slack between the gears. Make sure the marks line up before proceeding.
    #8
  9. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    Alright, sounds as if you said I am supposed to do everything the way we already did, except make it so it's one tooth advanced on the exhaust side. Then after setting the tensioner, and waiting a few minutes, it will be perfectly lined up. Right?

    Thanks.
    #9
  10. romeen

    romeen DSM Wiseman

    Classifieds Rating:
    100%
    Joined:
    Jul 12, 2006
    Posts:
    2,434
    Likes Received:
    23
    Vancouver, Washington
    I believe some guys do it that way.

    But I was referring to the tension that the exhaust cam places on the belt. You noticed that when you removed the belt the exhaust cam rotated CCW due to the pressure exerted by the valve springs. When you go to place the belt over the cam gear you have to rotate it CW to get the marks lined up again.

    What I do is rotate the cam gear an extra little bit so that the mark on the exhaust cam gear is just a bit below the corresponding one on the intake side. Put the belt over the exhaust cam gear as tightly as you can get it by hand, secure it in place using clips, then release the 17mm wrench off of the cam gear bolt. The valve spring tension will cause a bit of rotation CCW thereby taking up any remaining slack between the cam gears. Then proceed to loop the belt around the remainder of the pulley/sprockets.

    Hope that made sense.:)
    #10
  11. Turbo Talon DL

    Turbo Talon DL Proven Member

    Joined:
    Jan 29, 2005
    Posts:
    702
    Likes Received:
    1
    Quincy, Illinois
    If you follow the instructions and cross-check them from each source you use then you will be OK assuming you have the special tools to make things easier and a torque wrench or two. The belt will be somewhat difficult to install even with the tensioner pulley all the way to the 'left'. It will take a few tries but attention to detail will help you more than I can say. The exhaust cam will try and rotate CCW when you attempt to line it up. Use clips or reusable zip-ties to secure belt to the exhaust cam. Rotate it CW utill you get the belt 'cogs' to engage the intake cam gear's teeth and secure it. Route it around the idler pulley, the oil pump sprocket, the crank gear (you can move the crank a degree or two just to install the belt but align the marks once finished), and wrestle it onto the tensioner pulley. There is no real test for the belt tension itself other than ensuring the hydraulic tensioner is set properly and the tensioner pulley is properly torqued. If the belt is too tight then the tensioner will bottom out when the pin is pulled. If its too loose then the tensioner arm will be extended too far. The belt should be 'fairly snug' before and after the procedures are correctly followed. Just remember that you have to let the tensioner sit for about 20 min after you rotate the engine 1/4 turn CCW and then back to TDC. Dont 'nuke' the process as its pretty straight forward so long as you do everything prescribed properly.
    #11
  12. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    OK, well here is my situation:

    I have the special tools and the inch lbs. torque wrench, so setting the tensioner we got that down.

    The problem we had is:
    My crank timing mark is off half a tooth (CCW). I know, you can't be off half a tooth. Does that mean I am fine, then? The camshaft marks line up, we got that. But the crank mark is a half tooth off, in other words, it's not right on the mark, it is CCW a little bit, but not all the way to the tooth.

    What happens is that: everything is lined up perfectly, the belt is on the cams fine. When we put the belt on the crankshaft,, it ends up being CCW a half tooth I believe. Anyone know what I mean?

    At that point, with the belt on it, if we turn it so the crank timing mark is lined up 100%, I believe it then shows as the intake being advanced 1 tooth.


    So I am trying to figure out:

    1. Is it timed right or not? Is it ok that the crank timing mark is CCW a half tooth.

    2. If not, what are we doing wrong, and how to correct it.
    #12
  13. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    Take some pictures and post them up. Makes helping much easier.
    #13
  14. romeen

    romeen DSM Wiseman

    Classifieds Rating:
    100%
    Joined:
    Jul 12, 2006
    Posts:
    2,434
    Likes Received:
    23
    Vancouver, Washington
    Ditto on the pics.

    Also, using a straight edge make sure that the line between the cam gear marks extends across the middle of the cam gear bolts. Sometimes the marks appear to line up but extending the line shows it to go across the bottom or top of the bolts. It needs to go right across the center of the bolts.

    You might also want to pull the spark plug from cylinder #1 (t-belt side) and using a long wooden dowel (or something similar inserted down into the cylinder) to see if there is any appreciable change from TDC when the crank marks are aligned vs slightly off. Unlikely that such a small rotation will be significant but you never know.
    #14
  15. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    Thanks so far everyone. The car is 3 hours away from me so I can't get a pic, but I will. I could also upload a some kind of a drawing in the meantime that shows you what I mean.

    I did do the ruler trick and it is lined up across all 4 marks on the cam side.

    The crank sprocket is is a half tooth CCW from the crankshaft mark.
    #15
  16. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    Here is a drawing that shows what I mean. The timing mark is in-between 2 teeth.

    Imagine that the timing marks is perfectly in-between the 2 teeth, and that is what it looks like.

    Attached Files:

    #16
  17. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    You line the timing mark up with a notch in the trigger plate. It has nothing to do with the crank sprocket. This is how it'd look on a 6 bolt.

    [​IMG]
    #17
  18. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    OK, yes that is right. well mine is off the amount as shown though, of about halfway between those two teeth (like a half tooth off).

    Mine is a 91 6 bolt. It is CCW the amount show in the drawing (halfway between the tooth on the mark and the one CCW before).
    #18
  19. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    So does it or doesn't it line up with the mark on the trigger plate?

    If it does, you're fine, as long as all of the other marks line up.

    If not, rotate it until it does and see how close the other marks are. Sometimes all of the marks don't line up perfectly, but they're close enough to know they're correct.
    #19
  20. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    No it does not, but I may just need to turn it again, I just recalled the oil pump is not lined up (no BS so was not worried about it), but maybe that just means I need to turn it once more or so, and when the oil pump lines up, so will the crank.

    I will check it out, spin it some more and get back here and report. Thanks.
    #20
  21. steve

    steve DSM Wiseman

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Feb 3, 2002
    Posts:
    11,751
    Likes Received:
    141
    St. Charles, Illinois
    The belt isn't going to stretch in any sigificant way but it needs to be tight between sprockets or you will be off teeth when your done.

    When I do the belt I move the sprocket backward just enough to slip the belt on easily and then move it back to it's mark. If it will move past it mark without moving all the other ones then it's not on the right tooth. When I'm done the tensioner pulley takes up the extra and applies the tension on the belt but nothing other than the pulley should move.
    #21
  22. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    Ok, when we were putting the belt on, it was hard to put it over the crankshaft at first, so we slid it over the tensioner pulley first, is that ok? Which order should we do it? So it's cams first, then the pulleys, and finally the oil pump and crank last? Is the order also important?
    #22
  23. steve

    steve DSM Wiseman

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Feb 3, 2002
    Posts:
    11,751
    Likes Received:
    141
    St. Charles, Illinois
    Out of habit I start with the exhaust cam and work clockwise.
    If you start with the crank then you need to work counterclockwise because you have to end up with the tensioner pulley last.
    #23
  24. Spoolin4Ever

    Spoolin4Ever Proven Member

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Apr 24, 2005
    Posts:
    981
    Likes Received:
    12
    Moses Lake, Washington
    You do? I did not know that it mattered! Schucks no wonder. Well we put it over the pulley first then the crank because it was resisting going over the crank not sure why.

    So I will leave it on the cams, put clips on to hold the belt, pull the rest off, going round clockwise, and I will see if I need to turn the crank back a bit like you mentioned to get it on, that may be where we missed, along with putting it over the pulley first instead because it made it "easier". We instead should have turned the crank back just a touch to get the belt on it sounds like.

    We did the crank last, not the tensioner pulley. :hmm:
    #24
  25. snowborder714

    snowborder714 Moderator

    Classifieds Rating:
    100%
    DSM Profiles:
    1
    Joined:
    Oct 15, 2006
    Posts:
    11,698
    Likes Received:
    77
    Downingtown, Pennsylvania
    I would suggest reading through the 2 links posted in this thread a few times. They give great instructions on how to put the timing belt on.

    I do the same as steve - start with the exhaust cam and work clockwise.
    #25

Share This Page