Why my Mustang has Swollen Lug Nuts

There is a common problem throughout the automotive industries that has been around since the invention of the two-piece capped lug nut.  The problem is created when moisture infiltrates the space  between the chrome decorative cap and the actual steel lug nut that secures the wheel to the vehicle.  This scenario is compounded with the use of road salt and other chemical ice melting agents. These can cause rust and corrosion to develop and build up between the two separate pieces.  I am sure the vehicle manufacturers have a number of reasons why they chose capped lug nuts over solid.  The most probable is the ability to make a more intricate design in the aesthetics of the wheel nut rather than using a plain solid chrome lug nut.

Another issue with the lug nuts is the damage caused by impact sockets during tire rotations and  other types of vehicle service that requires removal of the wheels.  To make matters worse, sometimes a technician may use a standard size hex socket on a metric hex nut or vice versa.  Because the socket may be just a slightly bigger hex, damage can occur to the corners of the thin chrome metal cap which sometimes loosens the crimp where the decorative cap fastens to the steel nut.  It doesn’t take long for the cap to come off completely in this circumstance requiring lug nut replacement.

What’s the fix?  Fortunately, you can purchase replacement lug nuts for your vehicle from the vehicle manufacturer.  Unfortunately, you will have the same issues over time and they are not cheap.  You can also buy replacement lug nuts from other sources at a considerable savings over the dealer cost and yes, you will still face the same issues.  There is an alternative, and that is to purchase a solid chrome replacement lug nut.  Although they are different in appearance, they will resolve the issue of the separating lug nuts.  Be aware that there are a few things to know when purchasing replacement solid lug nuts.  One is to know the hex size of your lug wrench.  Although there are many different replacements available, sometimes you have  to go with a standard size hex like 13/16” rather than the factory 19mm metric hex size.  In this instance if you have a flat on the road and you have to use the manufacturers supplied lug wrench you are in big trouble.

So here are a few tips:

  1. Try and keep your wheels and lug nuts dry and clean especially if road salt is being used to avoid or delay the problem
  2. If you need to replace lug nuts and want the original look, check aftermarket sources for a better price, but pay attention to OE quality and specifications. If you go with the solid lug nut replacement, make sure they are long enough and have the correct size hex for your lug wrench.  It will save you tons of aggravation in case of a flat on the road.
  3. If you go with the solid lug nut replacement, make sure they are long enough and have the correct size hex for your lug wrench.  It will save you tons of aggravation in case of a flat on the road.

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