Sherpa 1979 17v "o series" engine petrol 1700 

Hi, Sometime back I replaced a new timing belt. Timing marks were lined up accurately only to find that the belt was 1/2 a tooth out. I figured this was to allow for belt stretching? I have since had an untraceable overheating problem that started straight after this installation. Is 1/2 a tooth out enough to cause over heating.

I will soon be putting on the timing belt again but armed with a little more knowledge. I have a choice (as I did back then - can't remember!) to pull up the belt from the right stretching it anticlockwise over the camshaft pulley or vice versa. My tensioner is located on the left.

  1. Is it completely irregular to have a new timing belt 1/2 tooth out or is that to account for stretch.
  2. I read somewhere that in this situation to put timing belt on in such a way that the tension in the belt should go to the tensioner side. (or something) 3 I'm now aware that depending which way I put the the belt on will have an effect of retarding or advancing the the timing. Am I right in thinking that I should err on to "advancing" to reduce the effects of overheating.

    As much as I try I can't quite visualize exactly the approach I should take - can anyone offer a little clarity?

1 Answer 1


I seem to remember there were "timing holes" where you had to put bolts or suitable sized rod through the pulley into the head / block and this would hold the pulleys still while the belt was put on.

Once the belt was on and the slack is on the tensioner side the tensioner is released.

Take the rods / bolts out and rotate the crank at least twice by hand and get back to TDC 1 , check the alignment of all the marks : if not aligned start again...

But check the manual as I may have missed bits...

  • Thanks Solar Dave, the info re bolts rods etc might be useful for making it easier to get on in the 1st place. I will look into that. Any chance you could expand/ give clarity to "Once the belt was on and the slack is on the tensioner side the tensioner is released." Commented Jan 13, 2018 at 14:06
  • Dave? So, you put the belt on and make sure that it is tight between the driven pulley(s) and the driving pulley, this should mean that the slack or the "loose" part of the belt is now in the same place as the tensioner. Now you can release the tensioner...
    – Solar Mike
    Commented Jan 13, 2018 at 14:32
  • Hi thanks Dave, I was putting the belt on with the slack on the non-tensioner side. That made the difference and now belt is not half a tooth out. Commented Jan 15, 2018 at 23:47
  • @MichaelSherpa why « Dave »? Have a look at my user name. If the answer was useful please tick it.
    – Solar Mike
    Commented Jan 16, 2018 at 10:11
  • Hi Mike - I looked into this for you and have absolutely no idea where "Dave" came from. Sorry! Commented Jan 17, 2018 at 0:13

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