"is usually impractical to actually measure how much a bolt stretches when tightened "

Actually measuring stretch is very common in automotive rod bolts. On the engines I work on (marine industry) all our head bolts, main bolts and rod bolts are hydraulically stretched for consistant torque. Frictional losses (or gains) are non-existant.

Not to mention how many people actaully have their torque wrenches calibrated...two units might have 10% or 20% different results.

Tighten until they get loose then back them off a 1/4 turn...kidding.

 

I do this, tighten all the way by hand then add 1/2 turn, minus a 1/4 turn, divide by a 1/3 turn, cross mulitply by 9/16 of a turn and add three turns to the left just for safe measure. Only had one wheel fall off, so my math must be correct.

 

Well it's been awhile since I posted this thread and theres been alot of good feedback.....and some good humor too. I did end up using anti-seize on my lugs and when I removed the wheels yesterday, lugnuts came off no problem and the wheels didn't stick to the drums. The lug nuts remained tight and hadn't loosened at all since the last time I rotated the tires. I now use the stuff when doing brakes and alot of other repeatable maintenance.

 

Most manufacturers now days actually recomend it. If you do use it, it is imperative that you have the correct torque (clamping force) on the wheel. Make sure you remove any loose compressable material (such as loose paint or rust scale) from the wheel and the mating surface (hub or drum), use brake clean and a wire brush to thoroughly clean the threads on the lug stud. Apply copper antisieze, sparingly to the lug studs and the cones of the lugnuts and torque to spec. I believe Chrysler spec. for the Cherokee is 95-110ft lbs. and retorque after about fifty miles and you should not have any problems with them loosening until your ready for them to. As an extra measure I ussualy recheck mine at oil changes whether wheels have been removed or not and have never had a problem.

 

I love antiseize. Works great on everything including lugs.

 

Cut it in half & double it.