Need torque help

[Andrmorr]

I'm changing out some 5 ton tires and need help getting to the 450 ft lbs the bead nuts need. My torque wrench only goes to 350ft lbs...bolts and torque usually move in a linear measure so can someone with a torque wrench that goes to 450 tell me how much further to turn the nut past 350? I'm thinking you would get the nut to 350, then draw a line on it and the wheel, then torque it to 450 and tell me how much further the nut was turned...It's not perfect I know, but it will get me closer than guessing until I can get a bigger torque wrench...I'm going to count showing threads & mark the rim/nut before I break the original setting loose just to see where they end up in comparison when going back which is something I've been wanting to calculate anyway since it might come in handy to know if you're back in the woods with no torque wrench...

 

[VPed]

Why don't you just use your body weight on a long wrench. If you divide your body weight into 450 ft./lbs., you get the distance in feet from the center of the bolt/stud/nut to where you should place your weight. Example: 200 lb. weight into 450 is 2.25 feet so 200 lbs. on a wrench (cheater pipe) at 2 feet, 3 inches from the nut equals 450 ft./lbs.

Easy to use in the back-woods and should be darned close to accurate.

 

[Andrmorr]

Why don't you just use your body weight on a long wrench. If you divide your body weight into 450 ft./lbs., you get the distance in feet from the center of the bolt/stud/nut to where you should place your weight. Example: 200 lb. weight into 450 is 2.25 feet so 200 lbs. on a wrench (cheater pipe) at 2 feet, 3 inches from the nut equals 450 ft./lbs.

Easy to use in the back-woods and should be darned close to accurate.

The problem is not getting to 450...it's knowing what the torque is on the nut...too little is not good, but too much is just as dangerous...Your technique looks good on paper but how would you apply it accurately especially since the wrench moves in an arc...It seems like it would be hard to get an even 200 lbs load applied considering breakaway torque (which might need to be higher) and continuous torque are two different things, and then when do you stop?

 

[VPed]

If the wrench is parallel to the ground and your weight is centered on the mark, you are at 450 ft./lbs. You can keep reindexing the wrench as you approach the final torque so the wrench handle is close to level. Breakaway torque would be a concern whether using this technique or using a high dollar torque wrench. By the way, this is how you calibrate a torque wrench.

I would say this method is better than the angle method because you are than assuming that conditions are identical for all of the bolts needing to be torqued. A plus or minus of ten or twenty ft./lbs. around 450 is perfectly acceptable and more than likely happening with your own torque wrench at 350 (unless you are in the habit of checking calibration of your wrench before each use). I have used this method for years on various stuff such as the single bolt that holds a VW flywheel to the crank, with no issues.

 

[Andrmorr]

Cool, thanks...that will go in the neat tricks tool box right beside the wax wrench!