Are Mechanics Lug Nut Challenged?

Early in 2023 I decided to upgrade my stock axles to heavy duty axles. The stock Dana 44’s that came with my Rubicon were good axles. They just weren’t up to how I use them and I had been having too many failures. An upgrade made sense.

When I picked The Whisky up from the off-road shop I noticed they didn’t use the original lug nuts that I had with my Mopar wheels. When I asked about it I was told that the old lug nuts weren’t deep enough and it was better to use the open end ones anyway.

I’m not a mechanic and I hadn’t planned to become one. Until recently, my strategy was to find a good shop with expertise and be willing to pay for that expertise to make sure The Whisky gets taken care of properly. There are a lot of ways this strategy has failed me. The lug nuts are one.

The wheels are the Mopar bead lock wheels. These wheels are a true bead lock wheel if you use the correct bead lock ring. But they can also be mounted as a standard DOT mount. They are a dual-mount wheel.

The lug nuts that came with them are an acorn style nut. They’re a bit longer and have a metal cap enclosing the end. It turns out the extra depth is necessary because the mounting holes on the wheels are recessed. They’re pretty deep. The length is needed so that there’s enough surface area of the nut accessible by the socket.

The cone on the original lug nuts is also deeper than the nuts the shop used. This makes me wonder if the mounting hole got deformed in any way by trying to use lug nuts that didn’t fit right.

The shop told me the original lug nuts were too short. In fact, four of them had holes in the tops. They looked like they were simply punched through by the lug when the shop used their impact wrench to put the lug nuts on.

I did a test. I swapped one of the new lug nuts out for one of the old ones with an intact cap. I used my impact wrench to remove the nut but I hand tightened the old one until it was snug then torqued it down to the 100 ft-lb spec. with a torque wrench. Guess what. It fit fine. What the heck was the shop talking about?

Here’s what I think happened. I think they just used their impact wrench to put the nuts on and over tightened them to the point that the lug pushed through the end cap on the nut. That’s the only way I see that happening. That also means they overtightened at least some of the lug nuts and that’s also not good.

I decided to change them all back to the original lug nuts. But I was going to wait until after I got the brakes checked. The brake shop was probably going to the same impact wrench over tightening that the off-road shop did. I figured I’d change them afterward and then properly torque them myself. I’m not trusting shops much these days.

They were only able to check three of the brakes. There was one lug nut on the rear, driver side wheel they couldn’t get off. The short lug nuts only allowed for about 1/8″ of surface to grab with the socket. With all the on-and-off, the points on the nut rounded over and they couldn’t get a grip on it.

I told them not to worry about it. I didn’t want them to try doing anything with it. This is the off-road shops responsibility and I was going to take it back to them. But the off-road shop is over 30 miles away. That’s a few hours round trip here in L.A. So I thought I’d give it a try myself before spending time and money on the round trip.

The first thing I did was get a socket that was the correct size. These short lug nuts are a 13/16″. The tech at the brake shop was using a 21mm. I know. It seems like that shouldn’t make a difference, but 13/16″ is equal to 20.64mm. That’s pretty close to 21mm, but it’s NOT 21mm. That small difference allows for some slack. A little slack on a nut that’s already worn can be a problem. So I went with the correct size socket.

The nut came off with NO problem. Maybe I AM a mechanic after all.

I swapped all the lug nuts out for the originals. I’ve had to order some replacements for the damaged nuts but those won’t be a problem.

The next time I’m at a shop for work that requires removing the wheels I’m gonna have to insist that they use the correct size socket AND that they do NOT use an impact wrench to put them back on. Hand tighten and torque. I can’t believe this is what I have to do, but it seems like that’s how it is these days.

I will be double and triple checking the lug nuts frequently for a while to make sure none of them come loose. I’m concerned forcing these short ones in may have damaged the mounting holes. If that has happened they may not hold properly at just 100 ft-lbs.

Who would have thought there could be so much to say about lug nuts!