Turning crank in opposite direction

[island03z]

I’ve heard that it’s not good to hand turn the crank in the opposite direction of normal rotation such as during setting TDC on a leak down test etc. Can anyone explain why?

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[Dustin Hicks]

[quote=”island03z” post=48378]I’ve heard that it’s not good to hand turn the crank in the opposite direction of normal rotation such as during setting TDC on a leak down test etc. Can anyone explain why?[/quote]

I believe that’s because you’d be turning the oil pump, cam, lifters, and crank bearings the wrong direction. That will damage all of those parts if done excessively.

[steven jacobsen]

Only reason I know is for timing, if you have a hydrolic or auto tensioner on the timing belt it can slip and jump a tooth when turned backward. As rare as that would be I never risk it.

[Jared Thomson]

You should be fine as long as you do it slowly. When you make jumpy movements is when you jam the tensioner and/or pop a tooth on the timing belt. The other thing is you want to be careful not to loosen the crank bolt. I would go forward unless its near impossible to, and you should be ok to turn it back if you overshoot some.

[island03z]

Cool thanks for the info

[steve]

Never do this if it has a timinng chain ..nissan etc

[island03z]

Any idea why?

[Author]

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