After removing the rear wheel on my 4th gen, I noticed a few of the wheel studs had some flat-ish areas on the threads. The lugs on these studs took a little wrenching to get them off. I'm the only person who works on this truck and I've always torqued my studs to 82-lbs, I'm very anal about this, so I don't believe over tightening is / was the cause. I have aftermarket wheels and I'm using Gorilla extra long acorn lugs. Wondering if these lugs are causing the issue? But that's a different question...

Being that the threads were slightly deformed, I figured a simple freshing up with a M12-1.5 die would do the trick. I pull out my tap and die set and grab the M12-1.5 die and to my surprise it would not engage the stud. I tried a few of the other studs and again the die would not engage. To confirm the size, which is clearly marked on the lugs, I grabbed an M12-1.5 tap and sent it down and back inside the lug. No issues. Again I tried to the M12-1.5 die but it would not fit. I decided that the die must be junk and bought a new M12-1.5 die. (different brand) Same issue. It would not fit any of the studs. I decided to just give it a go on the damaged stud, seeing that if it didn't work I would be replacing it anyway, I proceeded to re-thread it. Wow, it wasn't even close to the original threads. It sort of butchered the stud.

I've noticed recently that some of the metric die's don't matching with factory machined bolts. Which is really a mind-f to me given that a stated die size, e.g. M12-1.5, should match a bolt that is stated with the same M12-1.5.

Am I missing something? Is there a different M12-1.5 die that's needed specifically for a wheel stud vs what you get in your typical mechanic tool set?

Personally I would just replacement the wheel studs… and having done it myself the job isn’t that bad once you figure out what you are looking at.

Cleaning up the threads is fine too, but my concern would be if the bolts were ever over torqued and stretched (which you said isn't the case). Cleaning the threads might be all you need but as a precaution it still might be worth changing out.

Agree. They are easy to replace and in the end I replaced 2 studs. The only downside is it's a bit time consuming getting the rotor off and resetting the parking brake and all.

I'd still like the option of cleaning up the threads when I know there is no damage to the stud other than the threads and I don't have the time to knock out the stud. I'm still curious about the die sizing. I'm still miffed that I couldn't find a die that fits.