[keithC70]

Point 1.

Well I've done a few of these now and every time I've taken off the crank pulley.

Having read this thread and others, I was waiting to have a go at another to see if I could do it without taking off the pulley - so this week I bought an XC90 D5 and got the new bits, cut through the old belt and - couldn't get it out!!! Took the pulley off! I don't think it's possible - I tried for over an hour before I gave up.

Point 2.

A Newton is a force of 1 kilogram times g 9.81 ( Force = Mass x Acceleration)

So a torque of 300 nm is 300n at the end of a 1m bar

To change it to mass rather than force, you divide by g
which is 300/9.81 kgm = 30.58 kgm

so 300 nm is equivalent to 30.58 kg at the end of a 1m bar.

So if your bar is 1m long you need to press on the end of it 30.58 kg or 67 lbs. This is easy to do and shouldn't scare people from having a go.

Point 3

Interestingly, if you ask at a Volvo dealer in the parts dept. how many D5 cambelts they order for their workshop in a week, and then when they've replied ask them how many crank nuts and crank bolts they order, you'll see that they're not changed by the dealer! So I never change them either.

Point 4

Stretch bolts? What on earth do they mean? Every bolt stretches when it's under stress, and the more the stress, the more it stretches.

Think about the basic principle of Hook's law. As you apply tension, it stretches in a linear fashion and at any point in the elastic range if you de-load it returns to it's original length.

If it's gone past the end of the elastic range, it's passed the yield point and it's failed! Yet these bolts are called tty - torque to yield! I can't believe that these bolts are torqued past their failure point.

So if there is a recommendation to replace bolts, I think it's for another reason. Could it be that on assembly lines it's easier for automated tightening to continue until the force required is reducing? So they're not sure exactly what torque has been applied?

Anyone know the real reason?