Carpokes Porsche Forum

Hey folks,

I recently purchased a wooden shift knob along with its matching aluminum shaft adapter. The design is pretty straightforward: the knob threads onto the shaft, which in turn slides over a 3D-printed insert that fits onto the factory shift stem.

The parts arrived in good shape, pre-threaded, and everything looked promising. But during installation, things went sideways — the knob and shaft started to cross-thread, and once it started stripping, it just tore through the first few threads on both. At this point, the threads on both the aluminum shaft and the knob are toast. I managed to get the knob seated on the shaft, but with the threads chewed up, it won’t stay fixed.

A few important details:
• I need to be able to remove the shift knob from the shaft, because access to the set screws that fix the whole assembly to the factory stem is located underneath the knob.
• The 3D-printed insert isn’t super snug, so there’s a bit of play where the shaft meets the stem, which adds to the sloppiness.
• I’m not looking to go back to the manufacturer — this one’s on me. A little more support from them would’ve been appreciated, but I own the mistake.

What I am looking for is any advice from people here who might’ve faced similar issues. Is there a way to fix or reinforce stripped threads in a case like this? Should I be looking at thread repair inserts, epoxy, custom re-tapping, or even some kind of set-screw mod to secure the knob more reliably while keeping it removable?

Appreciate any ideas — I’d really like to salvage this setup if possible without scrapping the whole thing.

Thanks in advance!

Not knowing exactly what I'm talking about...have you tried tapping the knob and using a die on the shaft to get the threads back somewhat? If you can manage to gain some thread material, you can tighten up the fit by wrapping some elec. tape around the shaft before you thread on the knob. Maybe even throw a bit of blue threadlocker into the mix.

Or possible take the shaft and the knob to a machine shop and see what they can come up with. Just my 2 cents!

Can you post a picture of the threads in question? Can they be cleaned up with a tap and die?

So sorry I didn't update this. I managed to file down the remaining threads on the shaft, sort of flattening them down. Then I tried the knob again and saw that it was biting (or at least creating) the last few thread son the shaft. Went back and forth a few times and got a good bite every time. I went out and bought some lock-tight. Put quite a bit of that in and tightened the knob. I've driven about 5000km since (3000 miles) and it hasn't budged. If ever the knob needs to come off for service, I should be able to rank it off with my hands. If I need to use a tool and destroy it in the process, I'l just have to love with that.

Thanks for the reply.

Sounds like that'll work just fine! Worst case...buy a new stick and knob, no problem!