Timing chain. when to replace

[Shox Dr]

When would you change a timing chain. Bearing in mind the sprocket is integral to the crankshaft. Don't want that to wear out do we

[GSPD750]

Their is a measurement you can check by the amount the wedge projects above the tensioner unit. Illustrated and explained well in the Haynes on pg. 2-23 once the valve covers are removed. Max protrusion is 6 mm. It's self adjusting and should not wear out the crankshaft sprocket under normal conditions...I wud think.

We had a member here who had one of those teeth break off on the crankshaft due to stresses he put on it whilst taking the rotor off.

Pic shows the wedge with a nail through it in order to remove the tension so that the camshafts and chains can be removed.

[AlanH]

We had a member here who had one of those teeth break off on the crankshaft due to stresses he put on it whilst taking the rotor off

While taking the rotor off, a 2p or a copper washer in the primary gear is an ideal way of locking the crank. Make sure the camchain is kept under tension while doing this (a bungee is ideal) to stop the chain wrapping around the crank and damaging expensive stuff.

Getting the rotor off is the most awkward part of the job (unless you break an exhaust stud of course).

In that photo, the wedge you need to measure isn't clear as it has been pushed down to release the tension on the blade. The very tip of the wedge can just be seen resting on the mid-point of the nail.

The wedges are clearer on this one...



Hopefully your tensioners don't look like the bottom one

[GSPD750]

While taking the rotor off, a 2p or a copper washer in the primary gear is an ideal way of locking the crank. Make sure the camchain is kept under tension while doing this (a bungee is ideal) to stop the chain wrapping around the crank and damaging expensive stuff.

Getting the rotor off is the most awkward part of the job (unless you break an exhaust stud of course).

In that photo, the wedge you need to measure isn't clear as it has been pushed down to release the tension on the blade. The very tip of the wedge can just be seen resting on the mid-point of the nail.

The wedges are clearer on this one...


Hopefully your tensioners don't look like the bottom one

Ooops. I stand corrected Allan. Your right, it's the thick wedge not the thin wedge I have the nail through. Been awhile since I was in there. I almost wish I had a spare engine around to tinker and play with. cheers.

[XRV freak]

At what mileage is recomended to change the timing chain. I have 80.000km and realy don't know if should I change it or not.

What else should be replaced together with timing chain (tensioners......)?

[YEN_POWELL]

I had the chains replaced on my last AT at 70,000 miles as a precaution. The old ones were in really good condition.

When my current engine was apart for it's output shaft bearing replacement (50,000 miles), it was noted that the camchain tensioners were at the halfway mark. As I would imagine that when new the tensioner doesn't start at zero, I'd say there was a long life left in them yet. My bike is currently at 90,000 miles and the chains are still quiet.

[AlanH]

At what mileage is recomended to change the timing chain. I have 80.000km and realy don't know if should I change it or not.

You don't automatically replace them at a given mileage. It depends how the engine has been treated. Replace them when the wear indicators get to 6mm. If the tensioners show signs of wear when you replace the chains, replace the tensioners too.