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Trying to replace the alternator on a Monza 160 Junior, and the nut won't budge. I have done this before on a 250, and it wasn't nearly this difficult. I've tried heating, spraying with penetrating oil, etc...nothing seems to work. Open to any ideas before throwing the bike in the sea.

An impact driver will usually shift things, but failing that drill some small holes in one of the flats and with the nut/shaft supported on something like an axle stand or bottle jack,use a small cold chisel to split the nut and release the tension.

Maybe someone has loctited the nut with mega strong stuff, same advice as bob try an impact gun on it, or at worst drill a couple of holes in the nut and split it off.
Cheers,
George

Have you locked the locking tool against the socket so you can put some real purchase on a long extension? Never know a nut not to shift that way.

See pictures on our website:

https://www.laceyducati.com/ducati-part ... p-459.html

Keep the locking tool at the back of the basket. The picture shows the locking tool in the position for tightening, place the tool under the socket for undoing. You will note the scallop in the handle aligns with the socket diameter. Failing that, split the nut as already suggested.

Regards Nigel

Aye halfpast,

Would agree with Nigel that steady pressure on a "long extension" should work. I use a 60cm or 2' knuckle bar and if more pressure is required a 100cm or 3' length of scaffolding pipe can be added. The latter was required before I had an impact driver, either air or electric and the crank nut had been tightened after application of a 'stud lock' grade of thread adhesive. Reference George's "mega strong stuff"!

Now that I have an impact driver, I find it very good for removing these nuts. BUT! PLEASE DO NOT USE THE IMPACT DRIVER TO RE-TIGHTEN THE NUT ON ASSEMBLY! Use an accurate torque wrench set to 65ft-lb (Foot-pounds) or 88Nm (Newton-meters) and ensure that the thread is lubricated, not dry. Nigel may care to comment upon the torque value that I use?

Heat to weaken "mega strong stuff", is good providing that you don't destroy the temper of your drive gear or cook the alternator either electrically or magnetically!

Bevel Bob's drilling the wee holes in the nut and splitting the nut off, should be regarded as the last resort, but there is nothing "wrong" with the technique. Just hope that the "mega strong stuff" hasn't been applied to the inside of the driven gear and or the alternator flywheel taper to hold the alternator flywheel in place. Usually found because the taper has been chewed up when the nut slackened off after the motor was lugged in too higher gear, or insufficiently tightened earlier in its life!

Good luck, Bill

Borrowed my brother's impact driver and it did the trick. Thanks all for the suggestions and help!