Broken wheel studs is NOT a Toyota only,or a 4Runner only problem !Go to any forum and they all have these problems. I was in BMW and Porsche forums before this for years and the same ship.I had a Yukon Denali before the 4runners and they were broken all the time by tire shops.
Complaints of inferior wheel studs from the auto manufacturers over and over again and is far from anything new. Just google "ford broken wheel stud" or "any make or manufacturer-broken wheel stud".:ybrick:
My personal opinion is it is a
IMPACT WRENCH PROBLEM that is industry wide in the name of speed of putting the wheels on by the tire shop/dealer gorillas.:wow:
An impact wrench is a high torque tool that also hammers the nut as it is turning it on without any way to tell what your torquing it to.
Impact wrench - Wikipedia, the free encyclopedia So they inherently overtorque your lug nut on while the hammer in the impact is beating on it.Do you think that might stretch and weaken the studs. DAH! (slaps forehead)Then they break out the torque wrench on it. All they are doing is verifying that it has minimum torque.It has already been waaaayyyy overtorqued and stretched/weakened!
I work in an engine shop and have for years and we wouldn't be caught dead using IMPACTS. They are taboo and not the way bolts and nuts should be tightened by real mechanics unless they have a regulator of some kind to control the torque. We have torgue guns that are calibrated to run them down below the final torque setting and then we bring them up to final torque by hand with a calbrated hand torque wrench.Real important bolts we'll bring them up to torque in stages(like all of them in a pattern to 60ft/lbs then 90, then final 120) to insure an equal clamping force and equal the stresses on the bolts.
Some have said they have brand new studs break.... I would have to say that is a very very rare thing if they were installed correctly for a new one to break with it being torqued correctly.
As Jesse has said, I too have had my wheels off many, many times, at least 15-20 and have not had a broken one.Matter of fact 6 years of owning a 4Runner and never had one break. I now only go to one Discount tire store that puts my tires on and I trust and I tell them to not overtorque them and I will be watching them.
My 2 cents on "supposed bad Toyota wheel studs!":hatsoff: