Thread Adapter

[AlexJet]

I have a shifter knob with female M12 fine thread.
My shifter is male M8 fine thread.

I need a shifter adapter to convert M8 to M12 for the new knob.
Looked all over the place, but so far no luck. Can someone here steer me to the right place or give direction?

[I Leak Oil]

Not sure what it's made of but can you remachine the thread? Helicoil it?

[AlexJet]

The shifter is steel rod, and the knob is plastic.

I found HeliCoil for M8. (The model is for inner thread, am I right?) But I'm not sure the outside will get to M12 as its 4mm in diameter difference.

[ExpoMike]

I have made adapters before by taking a bolt, cutting it to size and drill and tapping it. This is not going to be a high stress part so that would work fine. Ideally having a small lathe helps to get the hole centered but it can be done by hand. Just get the lowest grade bolt so it will be easier to drill and tap.

[fourfa]

http://www.mcmaster.com/#catalog/118/3288/=g1tawi

That's catalog page 3288, some other suitable products on page 3289. You want M8 internal, M12 external, but you need to figure out the thread pitch first as there are a couple in those sizes. Walk into a decent hardware store and they'll have thread gauges. There are a couple choices of style and material.

[AlexJet]

M8x1.0 inner to M12x1.25 outer

[fourfa]

Well then, product # 90245A172

[Buliwyf]

Hack the shifter lever threads off.

Weld on a M12 bolt.

Whats so special about this knob? Why not just toss the knob in a lake and get one with the right threads?

[AlexJet]

Hack the shifter lever threads off.

Weld on a M12 bolt.

Whats so special about this knob? Why not just toss the knob in a lake and get one with the right threads?

Design...

[GlennA]

Fill the knob full of JB weld, then drill and tap the knob to fit the shifter. Most aftermarket shifters that I have encountered transfer noise from the transmission into the cabin. FYI.