1988 240 DL normally aspirated with about 300k miles. Since I've owned the car, I've only used a torque wrench to make the final tightening on all wheel lug nuts and use anti-seize.

I noticed that one front wheel lug nut will not torque to spec on several occasions. Switching lug nuts doesn't make a difference and the lug nut that won't torque on that stud torques just fine on other studs. The outside of the lug nuts are not stripped.

Now I'm noticing that there's a fine metal ring between the lug nut and base/stud, making me wonder if the lug nut is getting damaged.

I don't notice any new problems with the steering given my inability to torque that lug nut to spec.

However, out of abundance of caution, I switched out the wheel hubs with a good hub. The lug nut stud in question is off-car. Examining the threads doesn't show me any problems, except for another thin metal ring, which was not there last time I tried to torque it.

I've never had this problem with a lug nut stud. The hub is otherwise perfectly fine and I'd like to have the hub in service. What's going on and would a die fix the failure to torque to spec issue?

Thanks

Define “won’t torque to spec” —- what’s actually happening when you try to torque it?
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

Thanks.

Only on that lug nut stud, I confirmed the torque wrench setting, then tightened the bolt. I do NOT hear the torque wrench click or feel a change in resistance, i.e. I feel like I'm just spinning the lug nut. I torqued other lug nuts before and after with the normal click and increased resistance.

As machineman suggests above - if the threads look good (nut and stud), mark the end of the stud and confirm that the stud is spinning in the hub once the lug starts to tighten up. If that's what's happened you'll have to drive/press the stud out of the hub and see what's happened to the splines. Might be able to tack-weld the stud from behind to secure it. Alternatively find a stud with a slightly larger spline - re-drill/re-press. No idea if you can find such a stud. Probably easier to do what you've done - just put another hub on it.

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82 242-6.2L; '17 Mazda3; '16 Crosstrek

Thanks, CB and Michael Yount.

I used a wire brush, but not brake cleaner, when the stud was installed.

Last night, I used brake cleaner and a wire brush to clean the stud's threads in question. It was shiny, like new. I then installed the lug nut. It snugged up perfectly. Was there some debris on the threads that prevented it from torquing up?

I might just replace the stud anyway. Would you explain how to get the old stud off and install the new stud?

Thanks

A wire brush and that's it? My guess is that some of the thread, probably from the lug nut, yet lug stud will strip.

I had an incidence with Discount Tire in Spokane Valley, WA some years ago with the 1990 240 DL (li'l red) Wagon. They had stripped all the lug nuts using an impact wrench turned up to 11 (See the film "This is Spinal Tap") or rather well over 100 ft-lbs. On the right rear hub they had stripped all of the lug studs (and nuts).

My instructions to them were to hand thread the lug nuts and to not use an impact wrench.

The an owner can also muss up lug hardware thread.

Remember that using a thread lube, like anti-seize, reduces the friction counter force opposing the torque you apply, so you adjust the torque a little lower, though the hardware size makes them durable and forgiving. I think 86 ft-lbs is spec torque on 200 no matter the wheel type as in the owner manual and service manuals and here:

https://www.brickboard.com/FAQ/700-900/WheelsTires.htm.

Also, you torque in a pattern like five point on a star and go to the (relatively) opposite lug. I apply torque in three stages, using the star pattern, and a once around to verify the torque is even to spec.

Another repair shop for a MO-state safety inspection also used an impact wrench to check on brake pad and rotor wear. The tech applied unbalanced torque and can cause a rotor to wrap.

I also remove the tire / wheels myself, take the wheel / tires to the tire store, and remount these to the hubs meself. When I do so, I remove and reinstall the same lug nut to the same stud. (Though they do interchange around the hub fine.)

You inspect and clean the thread of both lug hard bits. Inspection may require a magnifying lens as damaged thread many not seem apparent to the unaided eye-bulb. The machine thread can flatten, removing the 'top' of the thread spiral. Round bits you are seeing are just that. Bits of thread pulled off from prior abuse or incorrect service. Phil Machine Man treats this topically in his reply.

The lug hardware can take up torque to spec using marginal thread.

Mr. Yount mentions the spine interface both secures the lug stud to the hub. Though I guess the stud did not spin?

The stud secures to the hub via a cplined interface. You remove the caliper and rotor to access the stud. Secure the caliper so it hangs out of the way with no stress on the flexible brake lines. Rotate the hub until the head (not thread) end of the stud on the backside of the hub is not obstructed by hub works bits. Use a shoe, piece of wood, what have you at the bottom (thread end) and drive / tap the offending stud out of the hub. Clean the spline interface, align, press in as you can with the 240 tire iron atop the stud and tap the stud shaft with the hammer to start securing the lug stud into the hub spline interface. You cannot fully seat the lug stud as the final seating of the stud occurs when you secure the tire to the hub (brake bits installed) post-assembly. You'll tighten and tighten yet not take up torque as the stud pulls up and seats to the point you can apply torque in the star pattern.

The lug nut is the softest alloy, the lug stud is a harder, more durable carbon-steel, yet, the steel that comprises the hub the lug stud secures to is the most durable steel of the three components. With an (exaggeration) 6 ft breaker bar and 19 mm deep well hex socket, so far as I know, the lug thread interface will fail and the lug stud can spin in the hub as the splines have failed before the hub is damaged at the splines. Though I have seen damaged lug stud splines on the hub in junkyards where the spline points are rounded.

Just to be clear (speech writer are you? =^), kittys are particularly fuzzy at this time of year.

Questions>

Hope that hepkats.

Unemployed Writer Duffed.
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Give your brickboard.com a big thumbs up! Way up! - Roger Ebert.

Thanks.

The tire/wheel did NOT move when I was trying to tighten the lug nut.

I used a strong magnifying glass and did not see any damage to the threads. It seems okay now, but I'll leave it as a spare part just in case.

Any thoughts on how to get the stud out to replace it with a new stud?

"Any thoughts......replacing stud?"

Yes. If it's working, don't replace it.

FWIW - one of the first things I do to any vehicle that I obtain (new or new to me) is remove the lugnuts, clean the studs and put a bit of Never Seize on them. Cheap insurance. Most torque specs are given for clean, lubed threads. So I'm of the opinion that the stated spec ASSUMES the threads are cleaned and lubed. If they're gummed up, I raise the torque setting on the wrench a bit.

I've always hammered or pressed the stud out (put lug nut on and turn it til it's flush with the top of the stud for more area to push on). Clean/lube splined area (male and female), get new stud started with a hammer, and then I place a few washers around the stud and use the nut to pull the new stud into place. Have to get a bit ingenious to figure out how to lock up the hub so you can use the nut/torque to pull the stud in.
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82 242-6.2L; '17 Mazda3; '16 Crosstrek

Geeeeeeez Louise.

Why don't you just replace the Stud and get some new lugnuts to have around.

Do you mean you actually removed the entire hub and put on another one because of a stripped Stud?????

IPD
https://www.ipdusa.com/products/4788/106758-wheel-stud

$1.55 each

https://www.ipdusa.com/products/4786/101703-stock-style-lug-nut

$0.37 each

Define “won’t torque to spec” —- what’s actually happening when you try to torque it?
--
82 242-6.2L; '17 Mazda3; '16 Crosstrek

Hi,

Make sure the stud is not turning by marking the stud end with a line or something. They are suppose to be pressed in to some fine splines when tightened.

Look into the bolt hole pattern of the tires rim too!

The angle for the nut, that the nut seats against, is probably mushed out!
This will groove each and every nut from here on out.

Some angles get really garbled up by tire shops.
It happens a lot because they run one or two nuts to pull the rim onto the center step on the face of the hubs.
Some “ill” trained personnel don’t work across from each other’s hole. They want to go around one time with air wrenches and then “should go back” with a hand held torque wrench and turn them in!
If it clicks it’s tight! Or too in some cases too tight, if it’s past the wrenches setting!
I stop at 80 foot pounds because it’s plenty and allows for any error!

They need to feel the turn and not the speed!
It’s all about wam-bam-thank you-mam!
This is a wrong place to be the “Top Gun” of tire changers!

Studs can break later or right then!
An unscrupulous shop owner might ignore it as it’s a lot of work to pull things down to replace a $3 stud. They say, “Oh! It’s got four out of five, many cars use only four nuts anyway!” Or “Heck it’s covered by a wheel cap!”
Therefore, the rim holes can get very mushed out!
When I bought my used 1991, it had both rear wheels with two missing studs!
It was a fair bargain in that it had one to each side, luckily!

I have saved a rim once by recutting the angles with a countersink but it’s a very limited proposition due to the depth or thickness of the material and how wide that you can go bigger! There is a little safety margin built in already but I don’t like seeing damage either!
I just smoothed or cleaned up the grooves to get back to some flat surfaces.

I suggest that if it just keeps moving in and not tightening up or anything like that, get another rim and new nuts!


Phil

Thanks.

Just to be clear, the old rim and the replacement hub just torqued up fine. I think I reused the old lug nuts (not sure due to trying to deal with the bleeding brake issue). Test drive is fine.

Thanks