How come new engines don't need to be re-torqued? I've
never heard of taking a car back for it's 1000 mile re-torque. Maybe
they did this years ago, pre-war?, but I don't know.
I always re-torque too.
It's common practice in the engine manufacturing business to tighten all
torques at once using very expensive multi-spindle machines. At least one
of these manufacturers has its machine programmed to torque the bolts to
different torques determined through extensive studies, and some nuts get
torqued, loosened, and retorqued, to take care of gasket relaxation and
results from reliability testing.
This torque-reverse-retorque is quite common in assembling very tightly
toleranced parts like hydraulic valves, hydrostatic steerings and such,
especially those made from aluminum parts.
uncle jack
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