It happened a little while ago so I put loads of threadlock on it and tightened it right up. Yesterday at Harewood, I noticed that the adapter would
rock on the splined shaft.
I took it off today to find the nut so locked I almost couldn't get it off, yet the adapter was loose. I still have the lock washer but there
isn't spline on the shaft sticking though the adapter for it to lock on to, perhaps 0.25mm. This may be enough for the adapter to rock a bit.
so how do I fit the thing without it working loose over time?
The problem you describe would seem to be lack of clamping pressure.
If theres nil clamping pressure the nut will come loose.
Perhaps you need some one to turn a custom spacer to sort this very critical problem out.
Rotational shafts coming adrift are the last thing any one would want to happen.
The tab lock washer will work so much better......
Is there a raised face on the front of the adaptor ? There was on mine.
I turned the raised face flat and then had enough room for the locking washer to sit on the splines.
quote:
Originally posted by fesycresy
Is there a raised face on the front of the adaptor ? There was on mine.
I turned the raised face flat and then had enough room for the locking washer to sit on the splines.
There was not enough spline showing on mine to use to lock washer correctly, I had to machine a couple of mm of the back of the adapter to allow more
of the splines through
Andy
Depends where you bought it from, some adaptors machine easier than others
weld it problem solved 
on a more serious note, have you had all the parts balanced?
We had this issue with the rgb cars - the way we stop it happening is to ensure that the bolt and washer bolt hard down onto the spline not the
adaptor, i.e the adaptor has a tiny ammount of end float. It seemed that if the washer contacts the adaptor first and then gets tightened it bells the
washer slightly and the resulting backlash and thrust serves to undo it no matter how much threadlock we used. as soon as we made sure the bolt
tightened against output shaft the problem went away. Can be as easy as fitting a very thin shim that fits inside the adaptor splines
regards
Andy
Also use Loctite Stud & Bearing fit ie the stronger red grade that is for permanent assembly rather than the Blue thread lock & seal grade.
-- we used to use it the CV joint splines of BL front wheel drive cars which used to develop a bit of free play -- sometimes more than a bit.
[Edited on 3/4/09 by britishtrident]
Samll spacer behing the adaptor so the nut/washer tighten to the adaptor face not the end of the shaft
From what you're saying (there's not enough spline for the tab washer to fit correctly) it sounds like you have a Honda adaptor, not a
Yamaha one. It's fine though, don't worry; all you need to do is as you suggested - have a couple of mm skimmed off the back face so that
the tab washer will fit on the splines. The nut should be undercut on the back to allow the splines to protrude into the undercut.
If it's an MNR adaptor that you're using I had the same problem with mine. Marc kindly skimmed a bit off so that it fitted properly. 