Help! Alternator pulley nut size?

[Napoleon Boot]

The nut holding the pulley to the alternator has whizzed off somewhere, never to be seen again. The washer and pulley were still in place, thankfully.

Anyone know what size nut I need? I’m hoping I might find something suitable at home as I doubt I’ll find it in a shop locally. Web searches suggest it’s M16 with a 24mm spanner size but if anyone can confirm, I’d be grateful! This is for a regular Lucas style alternator as sold for Minors by the usual suspects.

Thanks,
Seb

[philthehill]

The spanner size is 7/8" A/F or 22mm

Having consulted my Zeus chart and not finding any any answers I removed the pulley nut from the Lucas alternator fitted to my Minor & I find that the thread pitch is 1.5mm, the thread O.D. is 13.5mm and I still do not have an answer as to the actual thread.

Re-fitting the nut I have used a new shake-proof washer.

[Napoleon Boot]

Hi Phil,

Thank you for checking, I really appreciate that.
I searched around and found a spare alternator at home, I tried taking the nut off as a nice easy fix, but it’s incredibly tight and won’t come off without an impact wrench (which is probably a good thing).

So instead I’ve swapped over the alternators- the pulley on the old one was very loose and the hexagonal cut out in the pulley wheel is worn almost circular, so it was time to retire it.

I’ll still see if I can find a suitable nut as you never know when it’ll come in handy.

All fitted and she’s chugging along happily again- another lesson learned and another nut to periodically check for tightness.


Seb

[philthehill]

Well done.