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

[oceank]

I rent. Last time I rented it cost about $20/day, including the torque wrench and the socket. Nuts that require high torques are usually bigger, and I don't own sockets for those sizes either.

 

[Seabeckredneck]

Something that big, I use Star torque. Using a 3/4 or 1 inch drive rachet or breaker bar, get in a proper postition and just puuullllll until you see stars! That should be tight enough.
PS make sure you have something soft to land on incase the lights go out...

 

[Junbug1959]

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

Yes let’s get in to it (KISS) keep it simple stupid .
generally torque values are specified with a value in non lubracated threads. If you use lubrication than subtract 30 % off of the specified value. Remember you not rebuilding twin turbo 1200 hp funny car

if need to reference the Millwrights handbook there is here is a ton of useful info in it

 

[BeezFun]

I'm not sure if you are open to spending any money, but I bought a 3/4" digital torque adapter for this purpose.

Didn't know these existed. I just bought a 3/8" torque wrench not long ago, would rather have had one of these. Less space in the tool box and easier to adapt to hard to reach areas.

 

[California]

I had a loader cylinder rebuilt at the hydraulics shop. $165 and it came back with pipe wrench scars on the end cap.

Next time one dribbled I bought HF's 36" iron pipe wrench and had to add 3 ft of cheater pipe to get the cylinder end cap off. Total project cost $10 for seals and $20 for the wrench.

 

[DieselBound]

And then there's torque-to-yield! (initial torque value and then a rotational distance specified in fractional turns)

High torque value? Crank the crap out of it, operate and re-check: if it is holding up then chances are it's tight enough to stay that way- most everything is subject to eventual loosening anyway, no matter if properly torqued; it's a matter of how LONG!

 

[JWR]

I first encountered 600 ft-lbs torque numbers on bush hog blade nuts. Those are big healthy nuts. I don't know the size of your head bolts/nuts but I'd be very careful there.
Seems to me the torque multiplier is the concensus right route. However, I think I would try a big assed air wrench that claims to give 750 ft-lbs. It probably really will do 600.
Test 1 or 2 by following the air wrench with a borrowed torque multiplier and see how far off you are. Once you get the right settings you should be able to do this stuff very quickly, repeatably, and plenty close enough for your purpose.

 

[wpmlbg]

Sure it's not inch-pounds?

 

[JWR]

Sure it's not inch-pounds?

I do not know about the OP topic (head bolt nuts?) but I know for sure the bush hog blade nuts are in the 600 (I think they were 625) foot pounds area, not inch pounds. I had a blade carrier come off of a JD MX6 rotary cutter a few years back and go sailing across the field. Put it back on and tightened it as much as I could with a long arm and a 1/2" socket set. A few days later it sailed across the field again. Once I looked up the torque I knew why !! [And the blade nuts were similar torque numbers. So are mine on a 7ft Bush Hog brand cutter.] In the Deere hog case I used a cheater pipe and promptly ruined a socket and arm. Then went to a 1" drive and did it. Lessons learned... Do not own a torque multiplier but was told by my friendly Deere dealer that is what they use.

The 600 ft-lbs sure sounds high for head bolts....ridiculously high actually.

 

[ding beep]

Three "ugga uggas" and a grunt is the EXACT the conversion equivalent.

LOL. If I only need 600# of torque, I just make sure to only use 2 fingers.
Don't want to over-tighten anything down there...
ding beep