310 Foot Pounds - 3/4 inch bar or ratchet?

[MechManiac]

Hello All. I need to achieve 310 ft-lbs of torque for a 36mm axle nut. A torque wrench that capacity will only be used this once if i'm to purchase it. (DIY guy)

I'm thinking either a 22 inch long Wright flex handle. 3/4 drive

or

a 24 inch Wright ratchet 3/4 drive

with

ME standing somewhere on the end of the bar/ratchet to create the torque.

Which to buy? Having a 3/4" ratchet in a kit does add a cool factor

 

[NWphotog]

HF 3/4 torque wrench.

 

[Murphy4570]

A 1/2 impact wrench. Gud n tite.

 

[kiatech]

100 lbs 3ft from the center of the fastner.

 

[N.I.]

No need for 3/4.

Just use a 1/2 breaker bar and stand on it at the appropiate distance to give the desired torque. Frictional torquing is anything but an accurate science, even with a torque wrench.

3/4 drive is needed when you have a 2 metre long extension pipe and are jumping up and down on it.

 

[ironmutt]

get 155 pounds of what ever hang it from the very end of the 24" ratchet and there you go 310 ft pounds of torque but dont just drop the weight on cause that will increase the torque by the mass times the distance droppedby the time it dropped

 

[MechManiac]

hmm.....i'm afraid the longest 1/2" available is around 18". I'm worried i'll snap my 1/2" wright flex handle with a cheater pipe.

I've had issues in the past where tightening with an impact didn't really work out well (subframe bolts).

So that torque on a 3/4" ratchet is safe to apply?

 

[PT Doc]

How much do you weigh?

 

[zkling]

How much do you weigh?

This. I personally would use a breaker bar either 1/2" or 3/4" depending on your current socket size. No need for a ratchet, although that would be cool I can't imagine a 3/4" ratchet being very cheap.

I weigh ~175lbs, dead lift 315lbs for reps and give my 1/2" breaker bar hell. With a 4' cheater slipped over the breaker there isn't anything I haven't been able to remove. You would be amazed at how accurate you can torque something with a few weight plates a breaker bar and a tape measure.

 

[BK13]

I torqued my Jeep axle nut to 400+ ft/lbs. with a 1/2" breaker bar and my weight.


Of course, I do have 300+ lbs. of ballast...

 

[cryan]

Is there a tool hire shop near you? if so that might be the answer for one off use.

 

[unslow1]

I think I would get it as tight as I could. You can then leave the hubcaps off and run it by a shop a pay them to actually torque them.

 

[Jack Olsen]

Easy as pie. I had to stand 25" from center to get my axle nut torqued correctly. Nothing complicated about a foot pound. And so long as you know what you weigh, and can measure and mark a point on your cheater bar, you know that you're perfectly calibrated.

 

[kevin47]

Cheater bar, period...

 

[HTGTS350]

Possibly hire a 1/2 in 3/4 torque multiplier and use a 1/2 torque wrench to drive it, most multipliers are 3 or 4 to one so just work out your input torque from that.

 

[CaseyR89]

HF 1/2" breaker bar would be plenty strong enough. P.s. put the wheel on the car first, lower car from jack and torque the nut through the centerbore with the car on the ground, will make your life a little easier and less sketchy.

 

[Steinmetz]

Hello All. I need to achieve 310 ft-lbs of torque for a 36mm axle nut. A torque wrench that capacity will only be used this once if i'm to purchase it. (DIY guy)

I'm thinking either a 22 inch long Wright flex handle. 3/4 drive

or

a 24 inch Wright ratchet 3/4 drive

with

ME standing somewhere on the end of the bar/ratchet to create the torque.

Which to buy? Having a 3/4" ratchet in a kit does add a cool factor

Rent or borrow a torque multiplier.

 

[Steinmetz]

HF 3/4 torque wrench.

I'm not sure he has access to HF in Trinidad and Tobago.

 

[zkling]

Easy as pie. I had to stand 25" from center to get my axle nut torqued correctly. Nothing complicated about a foot pound. And so long as you know what you weigh, and can measure and mark a point on your cheater bar, you know that you're perfectly calibrated.

Jack, what ratchet is that?

 

[hofferwood]

I just let the kid do it

 

[MechManiac]

This. I personally would use a breaker bar either 1/2" or 3/4" depending on your current socket size. No need for a ratchet, although that would be cool I can't imagine a 3/4" ratchet being very cheap.

It isn't cheap you're right about that. When I go to the store tomorrow I'll see how impulsive I feel toward the ratchet.

I weigh ~175lbs, dead lift 315lbs for reps and give my 1/2" breaker bar hell. With a 4' cheater slipped over the breaker there isn't anything I haven't been able to remove. You would be amazed at how accurate you can torque something with a few weight plates a breaker bar and a tape measure.

If it's one thing I learnt from this forum is the applicability of tools to a job with safety in mind. I have the room so 3/4" drive , here I come.

Is there a tool hire shop near you? if so that might be the answer for one off use.

Tool hire shops in my country only deal with power tools. As far as fastener torque in my country goes, it's all muscle. My mechanic doesn't even have a torque wrench. Most people with torque wrenches would be large oil/gas companies. I wish I had many of the options some members have ! Good ole lever and a mass at the end will give me a fairly accurate value I'd be comfortable with.

 

[MechManiac]

Easy as pie. I had to stand 25" from center to get my axle nut torqued correctly. Nothing complicated about a foot pound. And so long as you know what you weigh, and can measure and mark a point on your cheater bar, you know that you're perfectly calibrated.

Thanks. This is what I intend to do. With my weight, i'll more than achieve it with a 24 inch bar/ratchet. Pic to come tomorrow on my decision.

Jack, off topic, but that's a cool garage you have.

 

[MechManiac]

I got the wright 3/4" bar (wright 6435) .

Very stout! I was going to get the 3/4" ratchet but both ratchet and bar had a matte finish. If the ratchet was polished chrome I would have taken that instead. This thing will take a serious beating and 310 ft-lbs would not even tickle it. Thank you all for your help.

 

[crewchief888]

I just let the kid do it

 

[BlindViper]

When I rebuilt my axle I had to torque the king pins to 550 ft lbs. I used my 3/4 snapon torqueometer and a 4' piece of pipe.

 

[G_P]

When I rebuilt propellers we would torque some of the big stuff by putting a big custom socket on then a 10' cheater bar on it and use a bunch of gym weights to get the torque right.

Good enough for the FAA!

 

[James_B]

I asked this same question on another forum about doing the 32mm axle nut on my Land Rover to the required 360 ft-lbs/490 NM setting. My tension wrench was good for an upper limit of 250 ft-lbs.

The most common suggestion was to do the breaker bar + tape measure + body weight thing.

I figured that I'd probably have to do this again and when a 4:1 gear ratio/1:3.3 torque ratio unbranded Model 11603 multiplier made by Williams Tools went on special for $70, I bought one.

One alternate method I was recommended was to make up a torque wrench extender (weld a square drive socket at right angles to the end of short breaker bar) and use the same calculations you'd use to work out the corrected torque if you fit a crow foot or a dog bone to the torque wrench.

 

[nexum1919]

just make sure to apply a DROP of engine oil on the threads before running the nut. also a THIN coat of oil on the flange area of the nut or the thrust washer contact area is a good idea. fasteners with unusually large amount of surface area will require light lubrication to achieve the clamping force desired with the indicated torque readings...

with that said a 1/2 ratchet should work just fine for the application.
should you want to step into the 3/4" world, i recommend this extendable ratchet:
http://www.amazon.com/dp/B0013VCBL6/?tag=atomicindus08-20
the best part is that the inside diameter of the extended sleeve is the perfect size to use as a cheater bar for 1/2 ratchets. i use this ratchet to loosen/tighten heavy duty two piece 33mm securex truck lug nuts (650 ft.lbs), spring u-bolt nuts, chassis u-bolts. most often used as a cheater bar for the 1/2 ratchet!
for the two piece lug nuts (flange washer and nut) it is recommended that a drop of oil applied to the tip of the threads and grease applied between the nut and the flange washer of the lug nut assembly to reach the desired clamping force with recommended torque. otherwise, with such a large surface area, most of the torque will be used up to overcome the friction and none will be left for proper clamping

for 3/4 sockets go harborfreight impact sets.