M40 Cambelt Locking Tool

[Type15]

The time has come for a cambelt change on my M40.

Where's the best place to get hold of the locking tool without paying daft money?

[Brianmoooore]

Not needed. A 10mm (or is it 8mm) drill bit serves as the flywheel locking pin, and the cam has a square section on it. Place a straight edge, such as a steel ruler, across this flat on the top of the cam, and check that the distance from the ruler to the machined area where the rocker cover sits is the same on each side.
The cam won't move when you take the belt off.
Haynes manual (it's online somewhere) shows a good method of tensioning the belt correctly.

[Andyboy]

As above.

But, slacken the cam pulley centre bolt. Fit the belt and tension it and the pulley (which moves on the keyway slightly) will move to where it wants to be whilst the cam stays still. With the belt tensioned, retighten the bolt.

M40 belts are so easy, easier to do than M20's but check the state of the rollers. If they're a little bit growly you can either buy new ones or pick the seals out finger a bit of LM grease in and refit the seals. Beware late Tourings as they have the E36 big tensioner that won't fit the older units. The change was around 1992.

[Brianmoooore]

Don't forget to take the drill out of the flywheel before you turn the engine afterwards!

[Simon13]

its an even easier job on an e36 with M40 if such a car exists still now

If you don't have a drill bit a 1/4 inch extention bar fits too to lock the fly

[Type15]

Thanks for the advice. I'll make sure I remove the drill.