Knob Retainer

[Leo Bolter]

Having just about lost one of my car's hood hinge frame securing knobs a couple of times, I set about doing something about it today.

The knob was set up in the lathe and centered.
1/ A groove was machined, positioned a couple of threads from the end. (about 5 mm diameter)
2/ A suitable "O" ring was rolled into the groove. Its outer surface needs to end up close to 5/16" in diameter.
3/ A wipe of silicon grease (or rubber grease) was applied and the knob screwed back into its threaded hole.

When refitted, the outward running of the thread is now only firmly resisted at the extreme of undoing, but still can be undone completely if required. Vibration causing undoing is completely defeated!

The above suggestion assumes that normally, when the your car's knob is undone enough to release the clamping of the frame hinge so it can be folded, there are still a few threads protuding at the back. i.e. enough protrusion to allow room to take the groove with the O ring.

1/

Groove & O Ring(pc).jpg

2/

O Ring Fitted(pc).jpg

. . . . more grist to the mill . .
Cheers.
Leo.

[Forumadmin]

I nearly censored this post!
Would a circlip also have worked?

[Leo Bolter]

I nearly censored this post

Whew . . . that was close!

Would a circlip also have worked?

"Good thinking, Archie" as Biggles would have said

There are two good reasons why I didn't do the obvious and use a Circlip.

1/ The hinge that the knob screws into (on my car, anyway) would have to be removed from the frame to put the knob in and to take out of the thread (if it ever was required to be removed).
While the end of the thread can be felt with a finger when the knobs are in place, it's nigh on impossible to do anything else no matter what state of erection* the hood is in.

2/ It didn't have that size Circlip in stock, whereas I did have "O" rings. As described above they can be screwed into place, with a little effort, as usual.

* I hope this term gets through the censor!

Leo.