A lesson in DIY car modification: Part 2

The newly drilled shifter knob being threaded.
After drilling out the old threading in my new knob with the correct drill bit, I took my threading tool and got to work!

At first you don’t succeed…

In one of my recent posts, I wrote about how sometimes buying a pre-made aftermarket part is a lot less of a pain than taking on a DIY car modification project. I had tried to take a surplus aluminum industrial knob and then adapt it to my car’s shifter for a fashionable, DIY shifter knob.

Unfortunately, I made some mistakes in the small project that basically ruined the knob, and I was forced to concede that it might have been easier to just buy aftermarket. Had I been a little more careful, I wouldn’t have ruined my project.

Well, after posting this story on Oppositelock, the community jumped onto the post and the comments started flying. Each commenter had an idea on how I could salvage the project and offered me encouragement to continue the project. One even suggested that I was lucky because it was “an inexpensive lesson.”

Thanks to that community and their ideas, I regained my confidence and decided to try again!

The newly threaded aluminum knob.
The newly threaded aluminum knob.

“…Try and try again.”

I had several options laid out to me. First, was the relatively simple method of filling the bore with JB Weld and letting it harden overnight. When it was hardened, I could take the correct-size drill bit and then drill another hole. Then, I would re-tap the hole with the thread tapping tool and voila; knob fixed! The only issue would have been making sure that the plug stayed in place during drilling, and making sure that the drill was perfectly center on the plug.

Second, I could buy some Helicoil and re-thread the hole to the needed thread size and pitch. This would have been much simpler than the JB Weld method, but I would need to buy a specialized toolset in order to do it. Seeing as the needed coil was just part of a standard toolset, I wasn’t about to shell out more money for something I was going to use only once or twice.

The third option was the simplest option: just but another knob and try again. The knobs themselves weren’t that expensive. Plus, they were less expensive than the other two options. So, I ended up just buying another knob to try again.

Getting ready to fit the newly threaded knob on the shifter.
The moment of truth: Getting ready to fit the newly threaded knob on the shifter.

Patience is a virtue

When the new knob arrived, I was ready. I had already gone to my local hardware store to exchange the drill bit I was sold. Luckily for me, they were more than willing to take the old bit back and give me the correct size! I had set up the workspace and made sure there were no shavings from the last attempt to mar the finish on the new knob. Also, I had slipped on some covered for the vice I was using so that it wouldn’t damage the knob.

Then, I got to work. The used the new drill bit and bored out the old threading from the knob, backing out every now and again being careful not to let the drill catch. The drill only caught once or twice, but thanks to the covers over the vice, there was no damage done to the knob when it decided to “walk.” It was slow and painstaking, but I managed to pull off drilling everything out!

Lastly, I took the thread tapping tool and gently threaded the fresh bore inside the knob. This part took even longer because I didn’t want to accidentally cross-thread the bore. My patience paid off though: I successfully re-threaded the knob!

Now, was the moment of truth. I practically ran toward my car and threw the door open. I swiftly unscrewed the old shifter knob and threw it into my glove box. Then, I held my breath and gently screwed the aluminum knob onto the stick.

IT FITS!
IT FITS!

It fits!

I finished screwing the knob and then stepped back to admire the work. It was then that I noticed that the new shifter knob accidentally matched with the chrome rollbar that came with the vehicle. At first glance, it looked like the knob was meant to be there! Ecstatic, I hastily put my tools away and went for a spirited drive through some of the country roads nearby to test the new knob.

I have to say, shifting is a joy with this car now with the new aluminum knob! Also, even at 100 degree days, the knob tends to stay cool so long as I park in the shade!

Lesson Learned

After my first attempt, I gave up a little too easily. I blame it on being frustrated that “my brilliant plan” didn’t work out the first time around. But, making mistakes is a great teaching tool. I had learned that if I took a step back and realized what went wrong, I would have the knowledge to succeed the next time around. All I needed was the encouragement from more knowledgeable people to try again.

So thanks Oppo! I’m enjoying my new shifter knob now!

A lesson in DIY car modification

Aluminum ball knob
The aluminum ball knob the day I got it. I was going to use it for my car’s shifter! It would have looked really cool…

Sometimes it’s just easier to buy aftermarket

I wanted a new shifter knob. It wasn’t that I didn’t like my current knob. It’s very well designed. It’s just that I wanted to refresh my car’s interior a little bit. The problem was that I didn’t like the look of any aftermarket offerings, so I decided that I wanted to make one myself. I wanted to try some DIY car modification!

I found this really cool aluminum ball knob on Amazon for a decent price: $16. It was close to the thread size I needed, plus it wasn’t over-sized and loudly colored like some aftermarket gear knobs I’ve seen. I figured I could buy this knob, and then make the necessary modifications needed in order to have the knob fit my shifter rod. The end result would have been a cool, Di-It-Yourself gear knob!

At least, that’s what I thought I was going to end up with. Instead, I’m writing about how sometimes it really is just easier to buy a damned aftermarket part.

Wishful thinking

I had the knob, which was a beautifully polished aluminum. I was told that the natural weathering would make the knob look even better after some heavy use. It was perfect for some DIY car modification! The only issue was that the knob didn’t fit outright, despite the closeness of the measurements. I would have to drill out the excess aluminum and then tap it with the needed threading. So, I went down to the hardware store for a drill bit and an M10 x 1.25mm tap.

I asked an associate for some help, and he gave me the tap and a 25/64 drill bit. Since I was making a new threaded hole, he thought that I could use this bit since it was very close to 10mm (9.9mm). I bought the tools and then I was on my way! After cleaning up the workspace and then prepping the tools, I fastened the aluminum knob to a vice, and then got to work with the drill.

Aluminum ball knob in vice
The aluminum ball knob in the vice I used.

Then, I made a mistake. I was tired of the protective covering slipping when I fastened the knob, so I removed them. The first few seconds drilling out the old threads, the drill caught and wrenched the knob out of the vice. My beautiful polished aluminum ball knob now had a gash because I removed the protectors. I let my frustration known with a string of expletives. But on the bright side, I had been thinking about finishing the knob with a brushed finish instead of the polished look. I could still salvage the project!

Measure twice, and then measure again

After I had the old threads drilled out, I went to my Miata and then tried a test fit. The now drilled-out knob slid right over the threads. I became nervous. Did I just completely ruin my project? I went back to the tool and brought out the thread tap, and simply used a crescent wrench to drive it in. It actually worked well, up until I tried screwing the newly-threaded knob onto the gear shift shaft.

The drilled-out aluminum knob
After finished drilling out the aluminum knob, I went to try it on the car’s shifter rod. As it turned out, the drill was too big.

My fears were pretty much confirmed when the knob simply slid down the shaft without gripping. My DIY car modification was completely ruined. I ended up throwing DIY shifter knob hard enough to break Delta-V and went back inside the house for a beer.

Test-fitting the aluminum ball knob
I tested the ball knob on the shifter and found that the hole and the threading were too big. You can also see the deep gouge the vice had made on the ball.

What went wrong?

I made several mistakes on this project and it ended up costing me the entire thing. First, I didn’t make sure that the drill bit I used was exactly what I needed. As it turned out, the tap had a recommended drill bit size, but neither I nor the associate caught that. Personally, I think this was the associate’s fault because he didn’t make sure either. Secondly, I didn’t take the proper precautions when fastening the knob with the vice. I had removed the protective covers on the vice because they kept shifting during the drilling process. Removing them not only marred the finish of the knob but ended up causing some damage that I wasn’t completely sure I could polish out.

Lastly, the cost of the entire project ended up missing the point of having an aftermarket-style knob, to begin with. I ended up spending almost $40 for a DIY solution when I could have gotten an already finished, brushed aluminum knob for around $20. Had I decided to simply look for something already available, I wouldn’t be writing this blog post.

Lesson learned

So, let this be a lesson to you if you’re planning on taking on a DIY project for your car: Make sure you have an idea for what you’re doing, don’t rush, and most importantly, don’t make something more complicated than it needs to be.

Now, I have to figure out if I can refund these tools so I can get that $20 shifter knob!

I’m obsessed with the Mazda Autozam AZ-1

Fiberglass body, gullwing doors, and mid-engined with a redline in the 9’s. It’s the Pagani Huayra of Kei Cars. Photo © The Drive

I’ve always liked Kei-Cars…

Designed to skirt around engine size regulations, Kei Cars are an interesting by-product of Japan’s need for personal transportation. These JDM-only cars are as unique as the country itself, often with interesting features that we could only dream about in the North American Market. Because of the regulations that birthed these cars, Japan ended up with a widely diverse group of vehicles designed with a certain-size footprint, and a maximum engine capacity of 660 cubic centimeters (0.66 liters). The Autozam AZ-1 was Mazda’s sportier interpretation of these regulations. 

Designed with a mid-mounted transverse 657cc Inline-3 motor making 63 horses, a fiberglass reinforced plastic body on a steel chassis weighing 1600 pounds, a 5-speed transaxle, and gullwing (!) doors, the AZ-1 had exotic looks and features in a minuscule package.

And I’ve got to have one.

Mazda only made about 4500 for the Japanese Domestic Market, but now that the car is more than 25 years old, you could legally import them into the United States and get them registered as a “gray market” import. In fact, there are several importers around the United States that would help you locate a foreign car, take care of the paperwork, and have the car shipped to you!

I want it…

After some looking around, I found a pretty decent if not heavily used example with around 120,000 miles on the odometer, and some body modifications. For a rare JDM-only car, this doesn’t seem that much of a bad deal for around $7,300! These cars are appreciating though as they’re now past the 25-year import rule, so now it isn’t uncommon for seeing low-mileage examples fetch around $15,000.

I guess I better start saving some money!

Photo © Bring A Trailer. Wouldn’t this thing look cool with Bolt-On Rim Fans?