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Old 11-20-2012, 04:27 AM   #23
amc49
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Think manual transmission, the total torque rating is shared by every part the power flows through and divides amongst them. Depending on how you fit the torque wrench in on nut (angle of attack mainly) the rear suspension can deflect some thus absorbing part of it. Same reason torque wrench manufacturers tell you never to put an hand on torque wrench head say using 1/2" fittings and six inch extension. When you load it, the whole thing can swing to one side and risk rounding off corners of bolt/nut. Human nature has you putting a hand on top of wrench head to steady it but doing so affects the torque since some is absorbed by your hand.

A torque wrench is nowhere near smart enough to know if you put all that power into just a nut or into everything else the nut was attached to. It just clicks to an given number. Put a wrench on front wheel bearings already installed say with atx in park, wheel free in air and twist load on the wrench and tell me how much load you just tried to put on the axle and parking lock inside trans, you can waste 25 ft.lbs. quicker than spit there just pulling all the looseness up solid.

I roll disc or drum while tightening maybe to 50+, after that the races have contacted, all you are doing is running up the force holding them together. Balls have done all the centering they are going to do.

If suspension components compress under the load, I assure you they ARE absorbing force, the wrench does not know that, all it reads is 'total' force, not everything force was applied to.

Having brake on does nothing, if bearing already run up partially, the brakes will have an easy .020" in sideways deflection front or rear before anything becomes a problem. At full torque runup you'll do well to get another thou out of the bearing. Even though brakes themselves are a force you are working against they force the torque to pretty much stay right there local to the nut.

Quick test of bearing after done, spin it, if there's a problem you'll know it. The balls better be right or the bearing was scrap to begin with. Never lost a one doing this, in fact they last forever.
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