Torque math

[GMC]

The listed torque for a 2" ball with 1" shank is 250 ft lbs. So if I understand this right that is 250 lbs of force applied 1 foot from the shanks. So... if I put my torque wrench in a 3 foot pipe I need to set it to 83, 84 lbs. (Give or take). Does this sound right? I want to make sure it's torqued correctly but have neither the torque wrench, nor the rear end on my frame to apply 250 lbs!

thanks

[nbhybrid]

can't see how that is going to work....the torque wrench is still going to click out at 83 or 84. Just get a bigger torque wrench that goes to 250...mine does and it wasn't that expensive. If you have any alloy wheels on your trailer or vehicle they need to be torqued to 110 lbs feet so you would have it do that

[Rustic Eagle]

GMC,

Your correct that the torque value is equal to the force applied at a specific length, and your 3ft pipe calculations sound right.

This link might provide some conformation (one way or another):

http://www.physicsforums.com/showthread.php?t=432352

Bob

[Rustic Eagle]

GMC,

I know with my Reese WDH the ball mount bolts (3/4 size) they have a 300 ft/lb installation specification. I torque the nuts to 150 ft/lbs, then I turn the nut another 1/4 turn with a breaker bar to achieve the 300 ft/lb requirement (per Reese).

There may be a similar method for the 2" hitch ball nut torque, I'm looking.

Bob

On Edit: The following link had some great information on the subject of "torque wrench extensions" (check out the calculator, confirms your approach):

http://www.freeinfostuff.com/TorqueE...eExtension.htm

[nbhybrid]

try and think about this.....if you put the torque wrench with the socket on the ball nut it doesn't matter if you put a 50 foot pipe on the end of it you are always going to click out the torque wrench at 83-84 ft/lbs or whatever it is set at.

In order to do what you want to do you would need to have the pipe on the ball nut and the torque wrench on the end of the extender bar. But there is no way you can do that.

Just get a regular bar and socket. put it on the ball nut with your platform in your receiver ,put your feet on the bumper and pull....I have never actually gauged the torque on my ball and in 25 years and tens of thousands of towing miles never had one come loose

[RickAE]

The torque value will remain the same if you put the extension on the handle of the wrench. it will just give you an advantage to not have to work as hard pulling.
If you put an extension on the socket side of the torque wrench then you have to calculate you torque. ( torque wrench length x the torque value is divided by the torque wrench length + extension length)
ex:torque is 250'lbs, torque wrench is 18" long multiply =4500. torque wrench =18" the extension is 12" = 30. Now divide 4500 by 30 torque =150'lbs.

[Rolling Thunder]

^^^ Uhhh... What now?

[nbhybrid]

Originally Posted by Rolling Thunder

^^^ Uhhh... What now?

I explained it my post quite well I thought.


putting a bar on the end of a torque wrench WILL give you more leverage or the ability to apply more torque BUT at the end of the day the torque wrench WILL click out at whatever value you set.. if it is at 83ft/lbs that is all you will be able to knowingly torque the nut to

[GMC]

Ah. Got it ,I was looking at it backwards. I see now that putting a pipe on the wrench would not multiply torque. Nice thought though right?! I guess the bumper pull method sounds good. One of my concerns was over tightening and weakening the shank. Now that I look at a 1" shank I don't think I should lose sleep over putting torque on it!

[nbhybrid]

you do multiply torque but you will not be able to measure it .

you are never going to over torque it. I never have and I work out

[Rustic Eagle]

The link I provided in my post #4 confirms the approach that the OP (GMC) described is correct. The torque wrench extension calculator actually is rather slick

On Edit: I may stand corrected, if I'm reading the link correctly the extension goes on the opposite end of the torque wrench, not the handle end ....... still reading. But it does reflect a way of measuring the torque.

Bob

[nbhybrid]

Originally Posted by Rustic Eagle

The link I provided in my post #4 confirms the approach that the OP (GMC) described is correct. The torque wrench extension calculator actually is rather slick

On Edit: I may stand corrected, if I'm reading the link correctly the extension goes on the opposite end of the torque wrench, not the handle end ....... still reading. But it does reflect a way of measuring the torque.

Bob

HUH????

So you are disagreeing with everything I said?

[Rustic Eagle]

Originally Posted by nbhybrid

HUH????

So you are disagreeing with everything I said?

You left out the 2nd paragraph of my post, or I was editing the same time you posted.

Bob

[Rustic Eagle]

GMC,

You can always give Reese a call and see if they have a similar method of torquing the hitch ball as the ball mount described in my post #4, which was noted in the Reese WDH installation instructions.

Just a thought.

Bob

[nbhybrid]

Originally Posted by Rustic Eagle

You left out the 2nd paragraph of my post, or I was editing the same time you posted.

Bob

I missed your edit and I believe the OP now knows it isn't possible

[Rustic Eagle]

Originally Posted by nbhybrid

I missed your edit and I believe the OP now knows it isn't possible

I agree, not possible putting an extension on the handled end of the torque wrench.

But it appears that a extension on the socket end will work if a proper length extension can be devised, with a setting at 83 ft lb producing an actual 250ft lb result ((based on the calculator, assuming 12" torque wrench and 24" extension (3ft total)).

Bob

[nbhybrid]

Originally Posted by Rustic Eagle

I agree, not possible putting an extension on the handled end of the torque wrench.

But it appears that a extension on the socket end will work if a proper length extension can be devised, with a setting at 83 ft lb producing an actual 250ft lb result ((based on the calculator, assuming 12" torque wrench and 24" extension (3ft total)).

Bob

sure could but unless you were needing to torque well over 250 lbs/feet the costs to make such an extension( I haven't seen one produced) would be more than to simply purchase a torque wrench that dials to 250 like mine.

I think I paid 60 bucks for it at Canadian Tire with a lifetime warranty

[wwsmith111]

I thought the original poster was trying to figure out how to torque the ball without a torque wrench since he doesn't have one. Here is how I do it. But a socket on it with a breaker bar and a 3' extension pipe and give it every damn thing you got. No way your going to break a 1" shank.

[eldermike]

I wonder how this torque spec came to be, why so high?. It's not for strength, torque adds no strength to the system, it could in fact make it weaker. I assume it's so the nut stays on the shank........but I don't know. Anyone know why?

[Bassdogs]

Stop at a local tire shop and ask them to hit the hitch bolt/nut with one of their heavy duty impact wrenches. Probably will do it for no $$'s but why worry about having the tools or knowledge to do it yourself when you can get it done by experts for little or no $$'s.

Did this when i needed a taller riser bar for our new WHawk. Tire shop loosened and swapped in the new bar and then retorked everything. Figure there is no need to get a strained shoulder or hernia doing this yourself.