You’re in the midst of changing a flat tire when you attempt to loosen one of the lug nuts, only to find it snapping clean in half on the stud.
Yikes! This is bad news. But don’t panic
With the right tools and some mechanical know-how, you can fix this yourself.
In this post, I’ll show you what to do if your lug nut broke in half on stud.
Step 1: Check Out the Damage
Before doing anything, inspect the wheel and try to see how bad things are.
Did just the outer lug nut break in half, or did the whole threaded stud underneath have gone into two pieces?
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Give the wheel a few hard tugs and shakes to see whether it still seems solid.
Any looseness or play likely means that the actual stud has broken, and your vehicle may be unsafe to drive now.
You can limp the car to your garage if the stud seems intact. But be super cautious.
If you can, call for a tow to avoid worsening things or, in some cases, to prevent the wheel from falling off.
Step 2: Get the Tools that You Need
With the vehicle parked, take stock of the tools that you need for this job.
At a minimum, have your lug wrench, a torque wrench, a tie rod end remover, and the proper replacement lug nut and studs ready.
If you want to save some cash, consider renting tools from AutoZone and other shops that offer tools for an hour’s pay.
Depending on your car’s make and model, you may also require tools like a brake caliper wind-back tool, brake dust shields, or even a drill and rivet gun if you must remove panels that are blocking the wheel hub area.
Step 3: Lift It Up & Lock It Down
You’ll need full access to the damaged lug area. Safely jack up your car and secure it on heavy-duty jack stands.
Support those stand contact points while the wheels are freely hanging up there.
You can now clearly see the broken pieces and have the room to work without hitting other vehicle parts.
Step 4: Break Out the Big Guns
The tough part is freeing those stuck stud pieces from the hub.
This is where that tie rod remover tool earns its keep! Fit it around the broken shaft base near the hub, with the threaded push screw centered on the sheared end.
Slowly increase the pressure, but don’t let it slip an inch.
This is because those studs are stubborn.
Keep your control and make sure to give the sudden force when the threads are free.
Step 5: Stud Extraction
Carefully wiggle the wheel to access the hub plate’s extraction holes and slots if needed.
Use locking pliers or magnets to angle and entirely pull that broken shaft out from the hub.
Take it slowly, because, at this point, all the brake and axle parts are crammed in. Then, clean the open lug bolt hole with brake cleaner, brushes, and rags.
Cover it up once the job is done until the new stud is ready.
Step 6: Getting It In
Test fit the replacement stud in its hole. It should slide smoothly without binding up.
Slightly open the hole diameter with a tap tool if it’s too tight – just a tiny widening is all that’s needed usually.
Then bring on the washers to complete this part of the job!
Thread a stack of washers onto the fresh stud, with a couple of snug lug nuts threaded on.
Now, you may be wondering why would I need to do that?
Here’s why – the washers serve as spacers for the torque to pull in the new stud perfectly. So, taking on this step is crucial to overcome this issue.
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Step 7: Torque
Follow your manual’s specs, which are usually 100 foot-pounds. Doing so doesn’t cause this issue to happen in the near future.
Remember that a quality torque wrench takes away the guesswork. Before declaring victory, test drive it to check for looseness or new vibrations.
If everything is solid, throw that flat tire back on!
Adding More Protection
I recommend adding secondary retention solutions for extra insurance against cracks and fractures that may happen again anytime soon.
Options like adding threaded sleeve locks, installing stud conversions with larger diameter shafts, or upgrading to chrome alloy hardened lug nuts can help to strengthen your wheel assemblies significantly.
Is It Safe To Use The Wheel With A Missing Stud?
No, you should always replace any broken or missing lug studs before driving again. Losing a single lug stud may compromise the integrity and safety of the wheel system.
I Broke A Stud On The Rear. Is The Process Any Different?
The overall process is the same, but the working room is typically tighter on rear-wheel applications.
You may need to completely remove the brake drums or brake calipers to access the hub and swap the broken rear stud.
Can I Use Any Grade Of Replacement Stud?
Stick to OEM factory-grade studs or better when replacing a broken one. Aftermarket economy studs often fail quicker than quality parts that meet the strict specifications.
Should I Replace All The Studs If Only One Is Broken?
Not necessarily – as long as the rest are undamaged after inspection.
But consider adding locking mechanisms to the remaining lug nuts or upgrading to chrome alloy studs altogether since one failure may indicate systemic wear and corrosion issues.
New Stud’s Shoulder Won’t Seat Flush
The stud shoulder fitment inside the hub is very precise. Carefully inspect for debris in the hole, damage around its chamfer edge, or minor mismatches in replacement part dimensions compared to OEM to overcome this issue.