How the heck do you guys torque a cylinder nut to 600 ft lb? Rebuilding Bobcat combo bucket cylinder.

[Gord Baker]

I am putting new seals in and apparently I need to get the bottom nut to 600 ft lb. I do not have that kind of torque wrench. How do most people achieve this? Thanks.

Tighten as tight as you can get it with a cheater bar then give it another 1/2 turn.

 

[clydesdale]

I have to give props to Summit Bobcat in Walden NY. They read the manual over the phone for me. 300ft lb is what the manual calls for and speaks nothing of thread sealant. I have a torque wrench that goes to 250ft lb.

 

[Streetcar]

Turn of the nut method is very common with 3/4” and larger bolts. Amount of rotation of nut after snugging is factor of bolt length

 

[RickB]

Turn of the nut method is very common with 3/4” and larger bolts. Amount of rotation of nut after snugging is factor of bolt length

And diameter, hardness, thread pitch and required clamping force. It's called 'torque to yield'. Very, very common in contemporary engines. Hardware is typically (but not always) single use.

 

[npalen]

IF you don't want to use a "torque" multiplier", One can always make a torque wrench extension....

Example snatched from GOOGLE IMAGES (not my work)...

View attachment 707015

Suggest if you going to 600ft-lbs to go big on fabrication...

Extensions Calculator - Van F Belknap Co

Use our extensions calculator to accurately determine torque values when using extension bars. Ensure precision and safety in every torque application.

belknaptools.com

I'm amazed that this setup works but it apparently does. Seems like the torque wrench needs to be measuring "force" instead of "torque" applied to the outer end of the extension lever. I guess torque is the same as force in this case, I'm just not "seeing it".

 

[California]

Seems like the torque wrench needs to be measuring "force" instead of "torque" applied to the outer end of the extension lever. I guess torque is the same as force in this case, I'm just not "seeing it".

Maybe you're thinking of torque as an engine or something revolves. That's rotational force x rpm = horsepower.

But in this case, torquing nuts, the rotational force is measured at zero rpm. So it is simple pounds applied - without motion - at x distance from the center of rotation. ie ft-lbs.

 

[npalen]

Torque is torque whether it is pistons torquing a crankshaft or a torque wrench torquing a bolt. It is force trying to induce rotation.

 

[Frankenkubota]

Maybe you're thinking of torque as an engine or something revolves. That's rotational force x rpm = horsepower.

But in this case, torquing nuts, the rotational force is measured at zero rpm. So it is simple pounds applied - without motion - at x distance from the center of rotation. ie ft-lbs.

and the continuing discussion about....

is torque measured in

ft/pounds

or

pound/ft

i had a physics prof go thru the entire derivation years ago that illustrated that torque is noted in pound/ft

you can measure auto speed in hours per mile but .....

funny how people disagree on this term

 

[Hay Dude]

I'm not sure if you are open to spending any money, but I bought a 3/4" digital torque adapter for this purpose. I knew my brush hog called for that level of torque, trailer lug nuts were 200, and the new gooseneck hitch I was installing on my truck needed 375. I would have probably settled for several ugga-duggas from my Milwaukee high torque 1/2" impact if it hadn't been for the Gooseneck hitch. That was the most important in my eyes, so I started looking and found this adapter. It may or may not be the most accurate item on the market, but I'm sure it was better than me guessing. For $80 or so, I haven't regretted it one bit, and have used it more than I expected.

Hey that’s pretty cool. Looks a bit delicate, but yeah, pretty cool.
Audible alert!

 

[mediplt]

I would use a cheater bar and the "TFAR" method. (T-that F-feels A-about R-right)

 

[WranglerX]

Got to wonder why the industry developed torque wrenches, torque multipliers and developed torque specification if a 125 pound person bouncing on end of 4 foot pipe is good enough....

 

[WranglerX]

and the continuing discussion about....

is torque measured in

ft/pounds

or

pound/ft

i had a physics prof go thru the entire derivation years ago that illustrated that torque is noted in pound/ft

you can measure auto speed in hours per mile but .....

funny how people disagree on this term

Well since all my work and specification seem to be in FT-LBS I won try to argue anything... I will just stay in FT-LBS arena...

But!

Torque Talk: Pound-Feet or Foot-Pounds -- Which Is Right? Does It Matter?

Whether measuring fastener tightness or engine output, torque always been confusing to enthusiasts. We aim to settle the debate for good!

www.enginelabs.com

 

[IndyJay]

Got to wonder why the industry developed torque wrenches, torque multipliers and developed torque specification if a 125 pound person bouncing on end of 4 foot pipe is good enough....

It is a matter of "calibrating" the 125 pound person. After you do this a few dozen times with a torque wrench (or after breaking a bunch of bolts/studs) muscle memory lets you know how much to apply to a give bolt diameter. In most cases, the recommended torque is a ballpark number, not rocket science.

 

[Greench]

Do we want to open the discussion on lubricated vs non lubricated surfaces and threads?

Its actually very important, 450 lubed is 600 to 650 dry. Buy an impact gun that does max 700 and let it rip.

 

[WranglerX]

Its actually very important, 450 lubed is 600 to 650 dry. Buy an impact gun that does max 700 and let it rip.

Do you really want to open up that can of worms....

 

[Frankenkubota]

Well since all my work and specification seem to be in FT-LBS I won try to argue anything... I will just stay in FT-LBS arena...

But!

Torque Talk: Pound-Feet or Foot-Pounds -- Which Is Right? Does It Matter?

Whether measuring fastener tightness or engine output, torque always been confusing to enthusiasts. We aim to settle the debate for good!

www.enginelabs.com

thx for posting that article! for years i've been trying to get a straight answer and that did it!

i kinda miss those old physics problems when, after 2 hours you look up and say, what the he// am i trying to figure out?

 

[BobInSD]

Or some other math solution. I'd use a 2.5 foot bar and my 240 lbs.

Assuming you can get the nut in a horizontal orientation, you don't need the exact distance. Say you have a 3-foot bar, so you want 200 lb. on the nut. If you weigh 240, stand on the scale and put weight on the 3 foot bar until only 40 lb is showing on the scale. My approach is that if the number is so high I don't need to be too exact but you can get as close as you want with the above scheme.

 

[newbury]

Assuming you can get the nut in a horizontal orientation, you don't need the exact distance. Say you have a 3-foot bar, so you want 200 lb. on the nut. If you weigh 240, stand on the scale and put weight on the 3 foot bar until only 40 lb is showing on the scale. My approach is that if the number is so high I don't need to be too exact but you can get as close as you want with the above scheme.

Assuming you have a scale handy. Most of the places I have to put 200lb of torque on a nut I don't have a scale that will weigh more than a few pounds available.
My bathroom scale is kept in my bathroom, about 100 yards from my shop.

 

[IndyJay]

Assuming you have a scale handy. Most of the places I have to put 200lb of torque on a nut I don't have a scale that will weigh more than a few pounds available.
My bathroom scale is kept in my bathroom, about 100 yards from my shop.

Redneck torque wrench... hook a fish scale to the end of your breaker bar?

 

[newbury]

Redneck torque wrench... hook a fish scale to the end of your breaker bar?

You've either much longer breaker bars, much bigger fish or both.