Pinion flange nut problem

[darcher121]

   
   

Anyone seen this before, as I haven’t!
When removing the pinion flange nut (forward end of the torque tube), the nut was stiff all the way off.
It seems to have stripped it’s thread, though the pinion thread seems OK but I haven’t measured it yet to find out.
Surely this can’t be normal?

[Colin Reed]

HI,
I Would say looking at the pinion Thread it has been damaged on the end which means as you undo it just rips the thread in the nut.
that damage will need to be addressed before fitting a new nut

Colin
NZ

[darcher121]

On closer inspection I think you are right. It lioks like someone has been at it with a large hammer!
The pinion flange will not come off so I guess someone lost their patience with it in times past.
If I had a spare pinion flange I would put a lot more pressure on the puller even if I bent it just to get it off.

[darcher121]

It’s off without damaging it!
Any idea what the thread size is as I will need a new nut and also a die to recut the shaft thread?

[Rogerfrench]

I'd try to clean that up with a thread file first. Starting a die over that might damage it further.

["Slack Alice" Simon]

If you don't have a thread file, a knife-shaped needle file will do.

Usually the biggest difficulty is that the end of the shaft has spread, so any file will do to bring the outside diameter back to where is should be.

Then judicious use of a fine file to make the thread look something like it should do.

Once the nut is past the "restored" bit, it is on reasonably good threads, and when tightened the rough bit is poking out past the end of the nut - so it hasn't got to be anything like perfect.

[John Cornforth]

Another vote for a thread restoring file.  The one I picked up secondhand has a square section with a total of 8 faces (4 each end) giving a selection of different threads per inch.

[Renaud]

We call it a FILON here. Mine is just like yours John. Metric but sometimes even useful on imperial!

[Bob Culver]

I do not have any books apart from Williams and he warns of the difficulty extracting the flange without bending it, esp on some models. He advises driving it off onstead of a 3 arm puller. Nevertheles I prefer to pull using a drilled plate. Whichever, supporting or pushing on the thread it is easy to burr or bend the thread. A stepped nut or collar or washer which fits inside the taper should be fitted and a nut or two fitted tight after this and extending above the thread. Less chance then of bending the threaded part. Maybe a use for the old nut if you can form a collar at one end. If tapers not distorted, as often are, and especially if assembled warm do not need immense pressure on the nut. Must not ride on key. Can rethread smaller but the above precaution then more important. This taper is one where checking with blue and maybe lapping may be helpful with little risk of complications.Must be no steps at end of taper.
If you have split dies these can be clamped onto the thread. Otherwise solid dies and die nuts often start out of phase and remove what is left! 1/2 inch BSF.(Every Javelin has 12 on the driveshaft so any local Club member will likely have many! )