Hitchcocks Forum

Is it essential to use the Hitchcocks pump worm spanner (pt no 98003 on page252 of catalogue) in order to remove the worm drive? I thought now that I have the timing cover off I might puton a new worm drive with it's built-in neoprene seal to see if that helps to reduce wet-sumping. Do you just put the engine in gear and unscrew it (left-hand thread, I assume?).

nope, a simple 19mm wrench will do.



take note that its a left hand thread.



to undo the worm drive, simply mark your idler pinions whit a felt marker.

so that you don’t screw up out ignition timing.

take one of them out and use it to block the crank.

Yep, as Mauri says. I found that a standard thickness 19mm spanner was actually too thick to get into the slot provided so I bought a (relatively) cheap one and ground off the face until it fitted. I keep it for just for this job but I do rebuild Bullet engines fairly regularly. For the cost of a spanner it's still worth doing even if just the once!

REgards, Mark

Thankyou for your advice. I've taken the worm off just by putting it in gear and very lightly tapping a standard 19mm spanner with a hammer. It wasn't on very tight at all. I can't think why there is a 'special' tool for the job.