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

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)