Custom Shift Knob

[KfabR8]

I've been trying to figure out how to modify the shift knob on my car for a while. I like the knurling, I like the shape, but it's sort of generic in a way. There's nothing that says "exotic" sitting there surrounded by carbon weave.

I've tossed around the idea of wrapping a knob in carbon. I've tossed around the idea of making a carbon sleeve that replaces the knurling.

I've had a few other ideas too, but I digress.

So today I felt creative. I decided that I was going to copy and/or modify the OEM shifter and put my own touch on it. Wasn't sure what I was going to do exactly until I started unscrewing it.

That's odd - the knurling seems to have rotated...

Sure enough, the knurling spins and that means it's a separate piece. That means this thing comes apart! (I'm good at taking things apart - sometimes not so good putting things back together - at least on the first attempts....)

So off I went trying to figure out how it comes apart.

I used a stylus and was able to push the shifter pattern button out of the aluminum body. Cool. I thought it was a thick sticker. And, I sort of had this plan in mind yesterday when I picked up the car (new clutch master cylinder seems to have solved the issue thus far), so I ordered a new button. The full knob is US$365, the button was US$69.59.

The top of the shifter has three holes. One in the center with some sort of plastic puck under it and a pair offset under the button - assembly holes!



Since my knob was already sort of scratched up, I decided to try and work it apart.

I already had plans to make a new knob, so this one was going to become the sacrificial lamb. I chucked it up in the lathe and started working out a non-tapered section so I could clamp it in the vice. I worked right up against the knurled ring so I could get it off (hopefully).

After putting it in a vice and going after it with pliers, it was toast, but I was in. Green locktite is a beast and I ended up twisting the center of the lower body in two - the threaded end stayed in the upper half.



I was right - there are two body parts, a knurled ring that's held in place with an o-ring and then a hard plastic sleeve that secures the knob to the top of the shift lever. It's like the nylon ring in a lock nut. The two pieces on the left side of the picture are supposed to be one piece.



Now my dilemma was what to make the body out of?
I had just the thing sitting on the shelf.


Titanium has a cool color, is tough, doesn't scratch, is "exotic" and just seemed like the right stuff for the project. It's fun to work with too. Nice, clean, doesn't make sharp chips & stringers. It DOES catch on fire like magnesium, though. I'd heard this was the case, and today I proved it! Fortunately it was a very small fire and fizzled out in a couple of seconds. It's not as bright as magnesium either.


Here's the bottom half in process:


Testing the fit between the bottom half and the knurled ring:


Here's the bottom half and the knurled ring being test fit against the top piece. I was still doing the bottom profile work and threading.




The final item!



Installed:



It's subtle, but I'm really pleased with the results. It took me about seven hours from start to finish.

[OEMplus.com]

THAT IS EPIC!!!

I hope there is A LOT of threadlock on that bad boy, or it's going to "disappear" when we see the car next month.

[desperado]

Very interesting project, and a great writeup!

I realize that in light of today's sad events this is somewhat after-the-fact, but what did you use in your new part to replace the nylon insert? Did you make a new insert? Use loctite? Or?

(BTW, if you get loctite hot enough it breaks down, so cooking it might be another way to get the two pieces apart.

For Disassembly:
1. Apply localized heat to the assembly to approximately 250°C. Disassemble while hot.

Although this is very close to the crystalline melt-point of nylon, so I guess you'd damage the nylon insert and ruin the part anyway...)

[KfabR8]

After getting it apart and realizing it was green loctite I thought the oven would be the way to go. The little nylon part, though, may not survive, as you've pointed out.

I used the same nylon piece that came out of the OEM knob. The hardest part about using it again was getting it out of the old knob. It's a slightly tapered hole that the piece resides in and it was definitely "in".

[Europrice]

Wow how did I miss this thread. That is **** cool.

[harrison]

Removing the skin grater knurling, and doing a cf wrap, might just be my cup'o tea.

[desperado]

I left the car in the sun today, and nearly burned my hand on the shifter knob. (Usually when the car gets this hot I'm at the track and wearing driving gloves.) I'm thinking black Delrin would be another great material for this project.

[OEMplus.com]

It looks like we have a host of options available! I am game to try some out...

[KfabR8]

Delrin would be a breeze. No need for the nylon plug to keep it from spinning. I'd probably make the knob one piece.

As far as a carbon wrap - that was my original intention. I wanted to do an aluminum knob with Ti and carbon rings. The issue, or at least what would make it harder to do, is that the section where the knurled aluminum is tapers a bit. That makes it interesting to do the separate rings.

Personally I like the knurled section, but then again I have tough, calloused hands as opposed to Harrison, who probably only holds a wrench to change his wheels. (just messing w/ya)

I have carbon tubing that could be make to work. Right now it's just the fabric and resembles one of those Chinese finger traps that we got as kids at the fair, but with a little work, I could lay it up over a tapered plug then cut to fit and go from there.

[KfabR8]

Just guessing, but the time and effort to do this is what would make it pricy. A custom carbon covered knob would probably run in the $600 range.