Can someone advise?

If the torque is 10lb & you manually tighten it (with tools) more than 10lb say 15, will the torque wrench loosen it back to 10lb?

 

No. It can loosen a fastner, but in the same way a regular ratchet does. Not to a specific torque. You shouldnt use it to loosen things, only to torque to a specific value. Always release it back to zero when done.

 

Absolutely.. Was using the loosening as example in the example

Good pt on returning wrench to zero

 

Now I have a question. My rear wheels are concave and I was trying to torque them but I couldn't because the wrench would hit the lip and/or body of the car. How do I accurately torque them to the correct specs?

 

Get an extension to use between the torque wrench and lug nuts.

 

But thought the extension threw off the torque reading.

 

If the extension used is flexible and long, it could wind up like a torsion spring. Actual torque applied to the bolt would be less than what the wrench is set for. For wheels I use a 6 or 8" 1/2" extension at the end of the torque wrench. Yet to have a wheel come off

 

Not anywhere near enough variance to make a difference when torquing wheels to 80 ft/lbs. If it worries you set it an extra pound or two.

 

This has been beaten to death all over the internet and it is patently false.

As long as you are applying torque by hand (i.e. not with an impact gun) and on a perpendicular plane with the axis of the bolt, then any resulting torsional action in the extension will stabilize as you twist the wrench and and thus apply an equal and opposite force at it's other end (think Newton's 3rd Law).

tite-tite, just slap an extension on there, support the knuckle end of the wrench to maintain 90* angle with the lug nuts and you can fully believe in your torque setting.

 

^^^ what he said...lol

 

That is correct. You cannot add or multiply torque along the single axis without a mechanism to add said torque. Now depending upon flex, energy may theoretically be lost to heat during the flex of the metal in the extension, but that energy would be so minute that it would not have any net affect on the torque reaching the bolt.

 

Yeah, the whole reason I mention doing it "by hand" was to eliminate the variable of any measureable loss. Given that when you torque by hand, you do it relatively slowly, so that any losses due to torsion in the extension (or even through heat as you say) will be stabilized and the correct torque will transmit through.

In the case where you are using an impact gun, then all bets are off since the torque is applied as a series of impulses, but each one only lasts a relatively short duration. In that case, it is possible for the torsional action of the extension to remain in flux and never truly stabilize, such that the actual torque transmitted out the other end will likely be less than what's being applied at the source.

 

Hmmm... so if you getting your tires done at Discount Tire & they use the gun to put the nuts in initially, drop the car & then torque..

if they are using the gun to screw in the nuts over 80lbs, say 100lbs & when the car comes down & they torque it to 80 lbs...it's no point, correct? (since torque wrench won't go back) ??

 

They use a "torque stick" that yeilds at a specified torque, say 60 ft/lbs. Then torque the rest manually by hand. So as to avoid the over torquing scenarion you just mentioned.

1/2In Drive Torque Limiting Extension Bar Set 10Pc

 

Actually, I was speaking of the torsion when torquing by hand (lol...looked like twerking) that would also cause heat. The twisting of the metal will create it, though in such small amounts that it is a non issue. I was being far too technical about the situation