This was a relatively easy project that produced a very unique and custom result. I love modifying my Jeep Wrangler, but it's even better when I can make a modification from scratch.
What you will need
Wood Lathe & Gouges
Choice of Wood
Nut and Bolt (Matching the threads of your shifter.)
Gorilla Epoxy Resin
How to do this project
Find a piece of wood that you would like to make the knob out of. I used a piece of Ash wood. I would recommend hardwood here since softer woods, like pine, are very porous and usually don't yield smooth surfaces when rounded. Also, I used such a large piece for two reasons: 1) I wanted a larger knob (since the smaller one didn't fit my large hands well) and 2) I'm still not proficient with the wood lathe and felt it would be better to have too much material than not enough.
Turn the wood to the desired size and shape.
Hollow out the wood on one end to the depth of the threads on your shifter and fill the hole with the epoxy resin. Insert the nut, threaded about an inch onto the bolt, into the resin. Let it stand for several hours to set up properly.
Use the bolt as stem to dip the knob in the polyurethane. I feel that dipping the knob rather than applying the poly with a brush fills any imperfections in the wood and produces a much smoother result.
Once the polyurethane has dried, carefully heat the bolt with a torch until you can back it out with a wrench. Be very cautious here because the torch can easily ruin the polyurethane finish. Also, don't heat the bolt so much that the nut comes out or spins; there should still be significant resistance when backing it out.
Let the resin finish curing for 24 hours. Once finished, install the new shifter knob on your vehicle.