Can you advise how to fix my turn signal assembly?

Where the chrome metal stem screws into the chromed plastic, the plastic threads are stripped. Might anyone have an idea how I can repair this? I want my bike to be original and not install a new one (a used one would be ok but I can't seem to source one)
Thanks
Dennis

Tap the threaded holes oversized. Use a BA tap for purity, or a 6-32 or 8-32 for convenience.

Slick

Are you sure Slick? Is not the metal stalk a good deal larger than a six or eight thirty two? You thinking of the lens screws?
The indicators are really a fit once and then good luck. You have to admire Lucas engineers making such absolute cheap jack.
Try using epoxy...

DennisMo said:

Where the chrome metal stem screws into the chromed plastic, the plastic threads are stripped. Might anyone have an idea how I can repair this? I want my bike to be original and not install a new one (a used one would be ok but I can't seem to source one)
Thanks
Dennis

Click to expand...

Try some JB Weld.

texasSlick said:

Tap the threaded holes oversized. Use a BA tap for purity, or a 6-32 or 8-32 for convenience.

Slick

Click to expand...

This is the stem thread on the early indicators that screws into the housing and is secured with an external locknut.

texasSlick said:

Tap the threaded holes oversized. Use a BA tap for purity, or a 6-32 or 8-32 for convenience.

Click to expand...

Onder said:

Are you sure Slick? Is not the metal stalk a good deal larger than a six or eight thirty two? You thinking of the lens screws?

Click to expand...

The lens screws (later? all?) have a self-tapping thread and the bulb holder screws appear to be 6-32 UNC, not BA.

Well, I was not thinking of the stalks......and after a re-read of the original post, it is clearly the stalks.........I agree with clffa, JB Weld might be best.

Sorry to mislead the OP.

Thanks so much for your advice. I have never thought to try tap threads in JB Weld. I would have figured epoxy would not be strong enough to
withhold the pull of the external locknut. Or are you suggesting to epoxy the stem threads into the plastic housing?
Thanks
Dennis

As I recall the thread on the turn signal stalk is an odd one, I ended up using a metric tap to make an aftermarket universal turn signal work...the fit was not perfect but good enpugh for a non critical part and it has stayed together for years now. I can't remember what size the tap was but I took the stalk to the hardware store and selected a tap that way, the SAE taps were not a good match.

DennisMo said:

Where the chrome metal stem screws into the chromed plastic, the plastic threads are stripped. Might anyone have an idea how I can repair this? I want my bike to be original and not install a new one (a used one would be ok but I can't seem to source one)
Thanks
Dennis

Click to expand...

Dennis, I'm surprised that you stripped the threads. The ones I have are either cracked or broken around the threaded hole (not a great design). The later style turn signal with the internal nut is a better design.

I found an early NOS Lucas turn signal head with a couple of stock stems on eBay here if you are interested:
Lucas NOS housing

Another option is to get the new later style Lucas turn signal assembly. Remove the stem and using a thread cutting die, cut either a 7/16-20 or 7/16-14 thread on the stem so that it would accept a chrome plated jam nut. When cutting threads I prefer cutting fine threads over coarse threads, it's just easier. Then reassemble. Doing this would make the turn signal look like the earlier style and nobody would be the wiser except for you of course.

Good luck,
Peter Firkins

It was like this when I bought the bike... I do want to keep originality so will find a replacement
Thanks

DennisMo said:

Where the chrome metal stem screws into the chromed plastic, the plastic threads are stripped. Might anyone have an idea how I can repair this? I want my bike to be original and not install a new one (a used one would be ok but I can't seem to source one)
Thanks
Dennis

Click to expand...

There are multiple original stem to body attachment types. Two pictures are needed. The assembled unit looking at where the stem meets the body, and one of that end of the stem with the body removed. I have a few original bodies in decent shape but none with the two flats (used the last one last week to replace a guy's in the same situation.