HOW TO: Broken wheel lug stud replacement (2 Viewers)

[Super77]

UPDATE: scroll down to post #7

Found myself with a cross threaded lug nut today. I knew it wasn’t coming off, so I just hauled on it until it broke. Here is how to fix that:

1. Toss out and replace lug nut
2. Remove lug stud, press in new one

Hint: it’s the second part that’s hard. The rotor has to come off, which means the brake has to come off. Good opportunity to inspect and adjust it. Once off, you’ll expose the hub, and full access to the broken stud.

The studs are splined and pushed in from the back of the hub, like nail. Many people just hammer the s*** out of the broken stud, pushing it backwards. Tried that (gingerly), with heat, but it was not budging. Figured I wasn’t doing the hub any favors with a bigger hammer, so I drilled a 3/8” hole down the center of the broken stud. Then I stacked up some thick giant washers around the head of the stud (behind the hub flange), ran a nut and bolt through the hole I drilled, and used a small impact wrench. The broken stud pressed right out, no harm to the hub flange. Didn’t get pics of the whole thing, but here is a pic of the stud. This is the back view (the part hidden behind the hub flange):

And the front, with what’s left of the threaded shank:

And what’s left of the threads, in a permanent loving embrace with the lug nut:

Replacing the stud is detailed further down the thread.

 

[excessive]

i highly recommend one of these when installing new studs, it has a little bearing in it that helps pull the new stud in with little force

 

[Exiled]

I carry a couple of spare lugs and M14 nuts in my parts kit for the same reason, although I confess I've just used a brass drift and BFH to back them out before. Your solution seems more elegant and less damaging!

 

[nissanh]

I never allow any shop to touch any wheel lugs... When getting new tires, I took the wheels off in my Taco to the shop to get new tires mounted. they torque those lugs to like 150 ft-lb!

 

[Aracobuilt]

That's one of the things that I like about Costco. They use a torque wrench on the lug nuts. Most tire places over torque the s*** out of wheel lug nuts with their impacts.

 

[Super77]

That's one of the things that I like about Costco. They use a torque wrench on the lug nuts. Most tire places over torque the s*** out of wheel lug nuts with their impacts.

My local Discount store uses torque sticks. No idea if they are accurate, but it tracks with the idea that if you give a 19 year old kid a $300 torque wrench, 1) they will mis-read it, 2) they will use it as a crowbar.

I also drop my rims off and don't allow them near the car. A box of donuts helps speed things along.

 

[Super77]

Well, want to update this thread now that I’ve done the whole thing. Getting the new stud in was not as simple as I thought, so here’s a little writeup for the next person.

Tools you need:
- 22mm socket
- strong impact gun (optional, risky)
- torque wrench capable of 120 ft/lb
- the little tool that @excessive mentioned above OR a stack of large washers and some grease
- an 18-24” piece of steel pipe, bar stock, or other sturdy way to prevent the hub from turning
- small wire brush
- new stud & lug nut

I used these, they were in stock and available as loose singles at my local O’Reilly. Nearly a perfect match to OE, reasonably priced, and an actual brand I’ve heard of, so I trust the grade markings

Here’s the stud inserted from the back of the hub:

Here’s my “washer burger” in lieu of the special tool. The stack needs to fit over the acorn end of the lug nut so the force you apply is borne by the nut’s flat washer. You do not want the angled tip of the nut contacting anything.

Here is the setup. I failed to anticipate that with the brake disc removed, I couldn’t set the e-brake to prevent the hub from turning. My e-brake needs adjusting, so it wouldn’t have held it anyway. The piece of bar stock is an easy hack, just make sure it’s against the hub so it does not damage threads on another stud. I used a small clamp to keep it from moving.

Push and rotate the stud from the back so it starts to find its splines. You want to reuse the existing ones, not try to cut new ones. Keep the washer stack and the lug stud thread well greased. Don’t worry, you’ll clean it all off later, and grease really helps if you don’t have the little tool. Do not apply grease to the splines.

Next is the hard part, depending on how well you did the previous steps. Pulling the stud through takes a LOT of force. I started with my impact gun, but I maxed it out and realized a bigger gun would risk breaking the new stud. So I switched over to a torque wrench set to 97 ft/lb, the lug nut torque.

I got it halfway in before the wrench clicked, and I alternated applying more grease and dialing up the torque. It took about 120 ft/lb to finally seat it, probably within the threads’ limits. Again, the little stud setting tool has a bearing that probably removes some friction, but my greasy stack was good enough for a one-off.

Check to make sure it’s fully seated

You should see just a peek of the splines from the wheel side of the hub.

Clean off all the grease. If you’re a lug nut fetishist (it’s ok, you do you) this is a good opportunity to wire brush all the threads and polish up the chrome. There was a surprising amount of gritty gunk on mine. So satisfying to have them just spin right on.