EagleTribune.com, North Andover, MA


May 25, 2014

Mystery of failed lug nuts


My first thought was whether the good Samaritan may have caused this by inadvertently tightening, then loosening the nuts. My suggestion would be to obtain a beam type torque wrench and measure the torque needed to remove the lug nuts on the other three wheels. This older style, easy to read torque wrench allows one to continuously view the torque applied rather than the more popular “click type” torque wrench that indicates a preselected value has been reached.

If you should find the other lug nuts to be excessively tight (specification is 80 lb/ft), take a photo of the applied torque just prior to one or more nuts coming loose. I’m thinking plus or minus 10 is reasonable, while more than 20 is certainly not. Should the readings be excessively high, I would hope the original shop would agree to renew all wheel studs and nuts as need be.

Excessively tightened wheel studs, besides the issue you’ve encountered, can warp brake rotors and damage wheels. Unless severely over-tightened I believe it would be unlikely you could lose a wheel while driving.

Brake squeak is caused by pad vibration. Softer composition pads and refaced rotors can wait until the next brake service. Your “smooth as glass” rotors may actually be too smooth, lacking the desired surface finish. New rotors may be needed if there isn’t enough thickness remaining to safely machine them. You may be better off with slightly thinner (but within spec) Toyota rotors than new, cheapo replacements. Insist on good ones!

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at under-the-hood@earthlink.net; he cannot make personal replies.

(c) 2014, McClatchy-Tribune News Service. Distributed by MCT Information Services.

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