Engine / Gearbox earths????

[froggy]

I've had the engine out a few times and never noticed anything but a mate who came round and helped me with the clutch asked if either the engine or the gearbox are earthed to the chassis.
Should they be and if so from where to where?

 

[noddy]

Yep there should be a short earth strap near the front of the gear box, looks like a shorter version of the battery earth strap.