Most of our shift knobs come prepared with a 16mm x 1.50 master thread. When you order your shift knob this is the default size when it states this: Simply measure your shifter to make sure you get the correct size. It will be either an unthreaded master (no threads) or metric/standard measurement. For standard, unscrew your current shift knob and measure the diameter of the rod. example 3/8". Then measure the tpi (threads per inch) down the shaft, approx 1" of threads. example 16 tpi. Therefore, you would need to choose 3/8-16 on the pull-down menu. For metric - similar thing, just measure the diameter of the rod, then you need to measure the thread pitch - distance between the threads, example: 10mm diameter, then 1.25mm thread pitch, you would choose 10mm x 1.25. I hope this helps. We cannot guarantee the size that you will need for your vehicle, so please check carefully. Our custom made shift knobs cannot be returned, although we can pull the master thread and put in the correct size if you made a mistake, but there will be a charge for this service.
If you are not familiar with replacing a shift knob, please check with a professional before removing your shift knob.
Our in-stock shift knobs come with a default size of 16mm x 1.50, which means it will come with two pieces in a small plastic bag with instruction to use the JAM NUT.
Once you have removed your current knob, screw the supplied JAM NUT onto the shifter rod, then the supplied REDUCER in the thread size you chose. Once they are on and secured lightly - screw on the shifter knob. Use the backing nut to position the knob where you want it. Then tighten. You must use the backing jam nut to keep the knob in place as it will not keep the knob tight, and you will damage the shift knob, which will void the warranty on it.
Once your shift knob is installed, we recommend using a threadlocker to hold the threads in place.