Tesla Center Cap Removal with Magnet

android04

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Crete, NE
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Model 3
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#1
*NOTE - I finally got my Model 3 and tested out this modification on the center caps. This did not work because my 75 lb pull mounting magnet is not strong enough. Next I will try using a 150 lb pull rated mounting magnet and update this writeup.

I bought a set of 4 Tesla dark grey center caps and lug nut covers so that I can take the Aero wheel covers off. I plan on putting the Aero covers back on in the winter if I have to drive a long distance, so I need an easy way to swap the Tesla center caps and the Aero covers. The Aero covers are easy to pull off, but the center caps are harder to remove. Here are some methods people use to remove the center caps, and why I don't want to use them:
  1. Use a ball of strong duct tape to stick on the caps and pull them off. It doesn't always work the first time, duct tape can leave a residue, and I want a more elegant solution.
  2. Use a suction mount (used to mount cellphones to windshields) to suck onto the center cap and pull. You have to find a suction cup that is sized almost perfectly smaller than the center cap's face, but bigger than the embossed Tesla logo that would so that it keeps suction.
  3. Drill a small hole on the center caps and use a metal pick to pull them off. I do not like this method because it makes the center cap look ugly to me and I might damage the face of the cap with the pick if it's too hard to pull off.
  4. Use a flat blade screwdriver or other similar tool to pry off the edges of the center cap. This seems like the most difficult way, and the one prone to cause more damage to the aluminum edges of the center cap face. Not to mention scratching the finish on the wheels.

So I thought of a better way to easily remove the Tesla center caps at will, and not cause any damage to the cap or wheel. Using magnets (one glued to the inside of the center cap and one use on the outside to pull) was the first idea. But I did not want a magnet in the center cap because random metal debris might stick to them during normal car use and detract from the aesthetics or even scratch the caps. So the next idea was to epoxy a steel washer inside the center cap and use a magnet on the outside to pull the cap off.

I went to K&J Magnetics website (www.kjmagnetics.com) and looked at what they had available. I wanted to buy everything from one place. I found some mounting magnets of different sizes and some rubber covers (to protect the center cap from damage) to go along with them. I wanted to buy the smallest, strongest mounting magnet and rubber cover. The smallest rubber cover that they had was 32mm (part # MM-RC-32 for $0.60) and I bought a matching mounting magnet that had a threaded stud on it (part # MM-C-32 for $6.37). The male threaded stud makes it easy to attach to something for better leverage when pulling the caps off. My plan is to drill a hole on the plastic lug nut cover puller tool and attach the magnet to it with a nut. Finally, I bought the four washers that would be epoxied inside the four Tesla center caps (part # NSWX02 for $0.75 each).

I was a little concerned that the mounting magnet would be too strong (rated at 75 lbs pull force) but decided to try it anyway because the center caps are pretty thick around the middle and that would diminish some of the attraction between magnet and washer. The thickness of the center cap is about 4.9 mm. I used a scale to measure the pull force between the mounting magnet and steel washer through the Tesla center cap. The average pull force before the magnet and cap separated was around 0.7 kg, which is not a lot and I don't believe it's enough to pull the center cap out of the wheel. I decided that if I reduced the thickness of the center cap (therefore reducing the separation between magnet and washer) it might increase the force enough to pull the cap out of the wheel.

The center cap is made up of three pieces (main grey plastic piece, aluminum cover with Tesla logo, and steel tension ring). I removed the aluminum cover by lifting up the 8 tabs on the back of the cap with a small flat blade screwdriver. Then the cover lifted right off.

I measure the pull force between the magnet and washer through just the aluminum cap (and skipping the grey plastic piece) at around 4.1 kg. I hoped that would be enough to pull the center cap off. Now I was able to make the center cap thinner by drilling a hole in the main grey plastic piece the same size as the steel washer. This would allow the steel washer to be right up against the thin aluminum cover to maximize attraction to the magnet.

I used rubbing alcohol to clean the two center cap pieces and the steel washers. Then I epoxied the steel washer in place making sure that there was a layer of epoxy between the aluminum cap and the steel washer to cushion the force pulling out. This will keep the aluminum cap from deforming, as well as help glue everything together. I also made sure that the washer (which has a tapered hole in the center) was placed with the wide part of the taper facing out towards the back and placed some epoxy into the hole so that it helps hold everything together.

Once everything was put together and the epoxy was placed in the right spots with the wooden stick, I bent the 8 tabs into place to hold the center cap together. Here is the final result.

I drilled a hole in the black plastic lug nut cover removal tool in order to attach the mounting magnet. Now it's an integrated 2-in-1 tool and makes it easy to grab the tool to pull off the center caps.

Here is a list of specs, but they should be considered approximate since my digital weight scale does not seem to be too consistent. The luggage scale used to measure pull force may itself be more consistent, but there is a human factor to consider when pulling the steel and magnet away and reading the highest number on it before it goes to zero.
  • Thickness of center cap, at the center point: 4.9 mm (with aluminum cover), 3.8 mm (without aluminum cover)
  • Thickness of aluminum cover, at the center point: 1 mm
  • Weight of center cap: 18 gm
  • Weight of steel washer: 10 gm
  • Weight of modified center cap with epoxied steel washer: 32 gm
  • Pull force with stock center cap and aluminum cover: 0.7 kg
  • Pull force with stock aluminum cover (no plastic center cap): 4.1 kg
 
Last edited:

oripaamoni

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Jan 25, 2018
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170
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San Diego
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#2
wow... bravo! what a great post and killer idea! I purchased a suction cup that somebody said worked for them but I love this idea so much more! I wonder if you found a bigger washer to sit in the back of the cap and then a magnet that was the same size of the cap if there would be enough pull force to avoid having to inset the washer. I will start working on this solution too and post my results! great idea!
 

android04

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Joined
Sep 19, 2017
Messages
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Location
Crete, NE
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Model 3
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#3
wow... bravo! what a great post and killer idea! I purchased a suction cup that somebody said worked for them but I love this idea so much more! I wonder if you found a bigger washer to sit in the back of the cap and then a magnet that was the same size of the cap if there would be enough pull force to avoid having to inset the washer. I will start working on this solution too and post my results! great idea!
A bigger washer and stronger market would work better, but I had no idea how strong of a magnet I would need (75 lbs of force sounded like a lot to me) and I wanted to minimize the added weight to the cap. After actual experimentation I had a starting point to making the magnets/washers that I bought work.

As soon as Tesla gets more center caps in stock I will be buying another set and might try the 42mm mounting magnet and rubber cover. It upgrades the pull force from 75 lbs to 150 lbs. The max diameter washer you can fit inside the cap is 45mm. I believe that the more volume of steel you have in the washer, the more attraction there will be.

Please update us with your results if you try a different approach.
 

android04

Active Member
Joined
Sep 19, 2017
Messages
120
Location
Crete, NE
Tesla Owner
Model 3
Country
Country
#4
Updated this writeup. I finally got my Model 3 and tested out this modification on the center caps. This did not work because my 75 lb pull mounting magnet is not strong enough. Next I will try using a 150 lb pull rated mounting magnet and update this writeup. If that doesn't work I might use bigger steel washers too. Hopefully this was not all in vain.