Author Topic: A65 Lightning Clutch Retaining Nut  (Read 709 times)

0 Members and 1 Guest are viewing this topic.

DAVID.FORSYTH@VIRGIN.NET

  • Star
  • *
  • Posts: 22
    • View Profile
A65 Lightning Clutch Retaining Nut
« on: 24 February, 2017, 15:13:25 »
Does anyone know how to lock the clutch retaining nut on a A65 lightning?

Arthur

  • Empire Star
  • *****
  • Posts: 105
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #1 on: 24 February, 2017, 16:51:10 »
Normally, a special lock washer (42-3191) with suitable tabs on it is used. That said, it seems to be missing from the 1965+ parts books for some reason, although this must be a mistake I would have thought?

Arthur

  • Empire Star
  • *****
  • Posts: 105
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #2 on: 24 February, 2017, 18:08:18 »
I think I may have been wrong. A65's from 1966 were fitted with clutch centre nut 68-3300 which I think may be self locking. Needs to be confirmed.

JulianS

  • Empire Star
  • *****
  • Posts: 557
  • A10
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #3 on: 24 February, 2017, 19:26:36 »
The original nut would have been an all metal aerotight type lock nut. These nuts have saw cuts. If your bike is still fitted with such a nut then it will be clear if it still has any "lock" left in it.

I would suggest use of a Loctite thread locker to be certain.

These nuts had a torque setting of 65/70 ft lbs.

The nut 68 3300 was changed in 1967 for a simliar one with better material specification part 68 3320. This was covered in parts service bulletin G40 from February 1967 part of  which is in the photo.
« Last Edit: 24 February, 2017, 19:28:59 by JulianS »

DAVID.FORSYTH@VIRGIN.NET

  • Star
  • *
  • Posts: 22
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #4 on: 24 February, 2017, 20:27:55 »
The nut on the bike looks like a locking nut as it has a turned diameter then the Hex but no saw cuts like a lock nut. I've looked on line at various photographs and some of the nuts show the saw cuts and others don't. Very confusing. Also I presume the turned section goes closest to the pressure plate of the clutch. It does fine on the other way round as the turned section can fit inside the bore of the pressure washer.

JulianS

  • Empire Star
  • *****
  • Posts: 557
  • A10
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #5 on: 24 February, 2017, 20:58:24 »
The way I see it is that the 4 spring clutches up to 1965 had a plain nut and lock washer and the 1966 on 3 spring clutches had a lock nut.

The cross section below is from "Motor Cycle" 2 September 1965 when the new clutch was introduced for the 1966 season. You can see the orientation of the nut - but also note that it shows a lock washer.

The second photo is from the 1966-68 workshop manual and again shows the orientation of the nut but no lock washer.

The saw cuts show in both.

DAVID.FORSYTH@VIRGIN.NET

  • Star
  • *
  • Posts: 22
    • View Profile
Re: A65 Lightning Clutch Retaining Nut
« Reply #6 on: 26 February, 2017, 18:30:13 »
Thanks for your help guys. Clutch now installed.