RPM gauge tachometer generator.

[E-type&XK150]

Good evening,

My tachometer isn't working: I've traced the fault to a damaged "drive dog" on the back of the inlet camshaft.

I've managed to get the old dog out, but the new (nylon) dog won't slip in to the slot. The "shoulders" of the drive dog are much wider than the metal one it is replacing.

Can anyone suggest how this is best done? Should one access the camshaft rear end by taking off the cam cover to expose it?

Many thanks,

Mark.

p.s. although this is for my XK150 it is fitted with a 3.8 engine that was originally in an e-type.