[Kalos]

Jays2000ZX3,Nov 8 2004, 02:01 PM Wrote:Someone please explain to me why it matters.
Just tighten them so they don't fall off, so that you can remove them next time and not enough to snap the stud. I have never and will never use a torque wrench then putting on some wheel lugs.

It wouldn't matter so much if there was some positive locking of the nut onto the stud - such as a jam nut - but there isn't. The only thing holding the nut onto the stud under vibration is the "tension" in the stud. this tension has to fall into a fairly narrow range between too loose and being so tight that either the stud is permanently deformed or the nut or stud are stripped. Also, overtightening can cause vibration due to brake assembly distortion, while undertightening can fail to dampen wheel resonance vibration.

Incidentally, the correct term is "lb-ft" - not "ft-lb". "lb-ft" is a unit of torque. "ft-lb" is a unit of energy. The sooner we convert completely to metric "N-m" the better.

All the shops I have seen use a torque wrench for final tightening. Admittedly their wrench is probably only accurate within 10%, and it looks like they use the same torque value for all wheels.