Non Laverda Crank Nut

michipons

michipons

Hero member
Location
Palma de Mallorca
Hi!!

I am rebuilding a Morini 500 engine, when I thought I had the control of the engine, I found THE NUT.

it is normal right thread, with four slots, and selfblocking (not anymore), I have found the spare on a UK web.

I started smoothly, with a self made four pin socket, first tried with normal wrench, then impact gun, nothing. Then a bit of heat with the gun, nothing. Then some real fire, nylon melted. Nothing.

I did a tool to impact directly into one slot with a big hammer, nothing.

I took a pressure pliers to hold the whole nut, put a long tube on it, nothing.

I would now cut it, but I am not sure how to do it, as I am afraid to damage the crank thread...

Any ideas how to go with it????

Miguel

IMG_7501.JPGIMG_7500.JPG266D8BFF-DD61-424D-ADDA-983CFDBACD7E.JPG
 
Cut it. Stop before the crank, you should manage to split the nut. If the crank thread is slightly marked, you can easily reclaim it.
Buy the correct wrench for that sort of nut.

Paul
 
Hi Paul!

The socket had been used many times in similar nuts, i have only seen some sockets that could have worked better, as they have the pins inside the socket, preventing (maybe) the deformation of the nut:

www.ebay.es

JUEGO DE VASOS ALMENADOS 1/2" DR. ALMENAS EXTERIORES 22 - 75mm, 11 PIEZAS - 1136 | eBay

Las mejores ofertas para JUEGO DE VASOS ALMENADOS 1/2" DR. ALMENAS EXTERIORES 22 - 75mm, 11 PIEZAS - 1136 están en eBay ✓ Compara precios y características de productos nuevos y usados ✓ Muchos artículos con envío gratis!
www.ebay.es

anyway, it looks like a good investment, i didn’t buy them because they are useless for the lav 500 castellated nut.

so, regarding cutting it... do you use a normal cutting disc? Or maybe better a grinding dremmel stone??
Miguel
 
You could use a Dremel, but it would take forever. If it were mine, I'd use a 100mm (4") angle grinder with a thin cutting disk.

You've gotta work your way into the corner between the face of that worm gear and the thread on the shaft. Go in slowly and carefully. As you're about to break through to the other side, you'll see it get red hot. That's telling you the metal is really thin, so stop there. Turn the crank 180° and do the same to the other side of the nut. Once you've only got a thin sliver of metal and bits of thread holding it together on each side, give it a whack with a drift or cold chisel. That last bit of metal will break and the nut will come off in 2 pieces.
 
If you buy the proper reinforced cutting wheel for a Dremel you will be surprised at how quickly it will cut through something like that.
It is also easier to be a bit more delicate with, but I'm just a back yarder (and my angle grinders are all fairly large ones!!)
 
Interesting. The only Morini I've done - a 350 Dart - I used a Honda socket on that nut and it came off easily.
Any evidence left of Loctite or similar compounds ? Thread OK ?
 
Every single nut, sprocket, case, bolt... is seized🤦🏼‍♂️🤦🏼‍♂️🤦🏼‍♂️
i have now troubles with the cam belt sproket on the crank end... and this one shouldn’t be cut as is probably difficult to find a spare
1611045820610.jpeg
 
Those fibre-reinforced wheels on a Dremel work incredibly well. The key is the rpm - if they aren't cutting fast-and-free, mess with the rpm (usually faster) until they do. The wear rate also reduces massively when you hit the sweet spot.
 
You must log in or register to reply here.
Back
Top