Torque multiplier wrench

[abn deuce]

I m not connected with this company in anyway just found the tool and thought it could help others out , I know I ve had a fun time when I was doing tire changing on my GMC of needing to jump on the bar , The only note would be to make sure your rotating the drive in the correct direction for MV's that have studs threaded differently depending on the side of the vehicle your working on .

On any youtube clip if you click on the youtube logo in the lower right corner it will take you to the clip as hosted on youtube and you see the listed information by the person who put the clip on youtube .

 

 

UK clip

Edited April 19, 2010 by abn deuce

[poppypiesdad]

right i just don't get it how does it work???, i get the ratios , i get the idea , but if its soooo tight how does it loosen it????

 

JAMIE

 

he sells his stuff on ebay

 

http://shop.ebay.com/uncle-grub/m.html?_nkw=&_armrs=1&_from=&_ipg=25

[griff66]

the way these things work is gearing you for instance put 50 foot pounds in, at business end 200 foot pounds output use them a lot on aircraft engine mounts 777 eng final torque on rear bolts from memory is about 350 foot pounds limited access so you would use a torque multiplyer 80 footpound fairly easy to achieve at output 350 etc.:cool2:

[abn deuce]

The ratio of these units is 60:1 so 40ft lbs torque in is 2400 ft lbs torque out . yes they are slow you need 60 rotations of the input shaft to get 1 rotation of the output shaft as he used the tool he only gave it 16 turns on the first nut then 24 last nut 23 ....if that wont budge the lug nut only a very large air driven impact wrench might loosen it or either tool would likely snap of the stud. I cant , pardon yes I can imagine someone having the misfortune to find some either cross threaded and or hopelessly rusted lug nuts but that should be the exception.

[Tony B]

I've got a twelve volt electric torque wrench, supper bit of kit.

[antarmike]

If this is what I think it is, these devices aren't intended for getting off very tight nuts. They are used to accurately torque down a nut, using a smaller torque wrench.

 

The gear ratio isn't exact. There is a deliberate over grearing to allow for mechanical losses (friction) within the torque multiplier.

 

The torque ratio might be for example 5:1 but the gearing may actually be 5.5:1 or similar to achieve this.

 

I have one, ( a NorBar) and the output shaft is deliberately undercut to weaken it, so this shears first, rather than breaking the internal gearing. The torque multiplier has a maximum input torque allowed, and hence a set output. Mine has an output of 1250 lbs/ft so I can get the maximum torque by driving it with a 250 lbs/ ft Torque wrench.

 

Visible in photo is a sheared output shaft, when I in desperation tried to use it to force off a tight nut. I learn by my mistakes and I now know only to use it for torqueing down free running nuts. ( I paid £35 for this tool at Ramco, but three new output shafts costs me twice this! List price is over £400 for the tool)

 

You have to limit the torque going in to the rating of the multiplier, so they are used with a torque wrench to drive them.

 

They are not designed to just have a big bar put on them and then to have have force applied until a stubborn nut comes free.

 

They should only be used to tighten free running nuts to a preset maximum.

 

 

Edited April 19, 2010 by antarmike

[griff66]

the ones i have used are nothing like 60=1 more 4 or 5 to 1 ie 100ft pounds in, 400 out.

[abn deuce]

this a is the Nobar one that is only to be used with a torque wrench to set nut and bolts to a set value , by using the tool to multiply only by a factor of 5:1 , not the same thing as the first tool I listed the youtube clip for that is made just to loosen stuck lug nuts