How to Tension Cam Belt ?

Hi All

just in the middle of stripping out the old cam belt and water pump while I await the new bits to arrive....

Question...

How do you tension the Cambelt ?

Is the tension from the tensioner pulley spring all that is needed ?? it doesn't seem a lot of tension but I cant see any other option....

Anyone ???

Thanks

I'm in the middle of a timing belt change myself (but I broke a bolt off in the head so I've been on hold waiting for parts) and getting the right tension should be rather easy. Using the spring is what is recommended, because if you get it too tight it will whine and wear the belt faster. Some will suggest replacing the spring every time you replace the belt but that isn't necessary AS LONG AS the spring fully returns to normal with no load on it, meaning all the coils of the spring are touching and there is no noticeable stretch to the spring. As long as the spring looks good, it will do the job.

The correct way to do it is to first:

-Run the belt from the crankshaft, around the lower idler wheel, around the water pump, around the camshaft timing pulley keeping it snug and making sure the belt teeth line up and there is no slack between those main components.

-Then push the timing belt under the tensioner wheel so everything is in it's normal place.

-Pull the tensioner wheel against the spring to loosen the belt and then smoothly and quickly release the wheel to let the spring tension the belt.

This SHOULD be the appropriate amount of tension on the belt and allows the spring to do what is was designed to do. If you are a little worried you can always push on the wheel ever so lightly while you tighten the bolt to make sure it stays snug. Don't push too much as this can just over-tighten things and then you'll have to adjust it once everything is back in place which is more annoying.

Since the belt spins at such high RPM (from the high revving motor) the centrifugal force more than compensates for any perceived slack in the belt. When I removed mine for replacement after 45,000km, the tension felt loose compared to some other engines but when reassembling the new belt tension matched the old one, and the old belt showed no signs of stretching or any serious wear. It may have been a perfectly good belt but I don't want to take any chances.

My information comes from reading everything I could find on this site and online about this belt change and timing belt changes in general. Hopefully it helps you!

Thank you. good info to know.:)

Excellent.... as access in the car is best described as limited :-)

cheers

I made a detailed Step-By-Step guide that I posted here - should help anyone who wants to do the job!

http://www.u-ukhbc.co.uk/vbb/showthr...-By-Step-Guide

Joshua
WatchmanPP1