cam belt jump with fast gearchange on 4age?

**AE25** · 14-02-2008, 08:42 PM

lightened flywheel, heavy puck clutch, turbo and sticky tyres...
anyone had any issue with crank pulley jumping teeth?

**Vios-GT_07** · 14-02-2008, 08:51 PM

^^

could be the cam belt tensioner needs attention?

**merc-blue** · 14-02-2008, 09:18 PM

You you would need a serious tensioner issue to jump a tooth,
More so if your changing gears properly.
I cant see how you could jump a tooth on a properly maintained engine when similar belt drive engines are being slammed on dogs at 9k RPM

**AE25** · 14-02-2008, 10:31 PM

hmm good point.. tho bit of a rev change difference using a close ratio dog box compared to using a w55 from 1st to 2nd at the drags

not my engine that did it.. but got me worried for the one im building.. would like to know if this not the only one to do it and if i should be looking into it more

**jeffro ra28** · 14-02-2008, 10:41 PM

if the belt was tentioned correctly, it would more likely snap, not jump teeth. me thinks anyway

**merc-blue** · 14-02-2008, 10:42 PM

If you changing properly you really shouldnt be able to jump a tooth,
you would have to have both these things wrong for it to happen,
1. Poorly built/maintained engine
2. complete lack of gear shifting ability, often refered as a part of "mad skillz"

**IN 05 NT** · 14-02-2008, 11:15 PM

if belt is flopping in the breeze, yes you can jump teeth, how much move ment do you have on the belt, if you push down on the belt between the cam gears,

you should have bout 3mm flex between the cam gears.

you can also damage the teeth on the belt by it being to slack.

dont leave it, check it, done 2 ENGINE headjobs