Torque Wrenchtoo small

[Young Farmer]

I need a torque wrench that can tighten a hub nut to 200 ft lbs. My torque wrench will only go up to 100 ft lbs and a suitable torque wrench is a hell of a lot of money to only use once or twice. If I make up an extension to move the pivot point from the centre of the nut being tightened to a foot further away will this halve the amount of torque required? This could be done quite easily by welding two old sockets a foot apart on a bar. Any other ideas?

[Luxobarge]

Any other ideas?

Yes, use a breaker bar and just do it up as tight as you can. This is the sort of torque setting that's known as "FT" in the trade (F***ing Tight).

Sorry if that sounds a bit unprofessional, but I bet you it won't come undone....

[tractorman]

I used a spring balance and a length of 3/4" water pipe for the job (a long time ago). A couple of jubilee clips stopped the balance's hook from sliding along the bar - which fitted nicely over the t-bar of my socket set.

I'm not sure how high the modern spring balances go - you may end up with a 25Kg balance and a four foot long bar (if you don't mind the mixed units). I'm trying to remember the capacity of the ones I last used for mixing calf meal; which we bought in 25Kg bags and mixed ourselves - it was that long ago!

I have to agree with Luxo though (he posted while was typing) - do it up "dog tight" and it will be fine.

[TerryG]

I think the only bolt I have had to tighten over 160lb/ft that my torque wrench can go to is the crank bolt on my v8. To torque it up, I wedged a spanner between the crank and the block and put a 6ft breaker bar on it then stood on the end.
It hasn't come undone in the 5 years or so since I did it.

[Richard Moss]

Weigh yourself and then stand on the breaker bar at the appropriate distance distance from the socket. A 200lb person would stand 1 foot out, a 150lb person 1.3 feet out and so on.

That said, 200ftlb hub nuts can just be done as tight as you like - I just stand on the end of my 2ft breaker bar and job done:)

[Minxy]

In a previous life I worked extensively on Audis. The crank pulley bolt on a Audi five cylinder had to be torqued to 450Nm or 350 if using a special tool that was bent to shape for access and was approx 18 inches long. We used a three-quarter drive torque wrench. Certainly on the Audi pulley bolt accuracy was paramount so I would have to disagree with the idea of just doing it up tight. I do have a three-quarter drive torque wrench but I suppose the chances of you being local to me are slim?
West Northants?

[Pavel]

Do it up as suggested -- bloody tight -- but add a little Loctite. It wont unscrew itself.

Pavel

[Richard Moss]

In a previous life I worked extensively on Audis. The crank pulley bolt on a Audi five cylinder had to be torqued to 450Nm or 350 if using a special tool that was bent to shape for access and was approx 18 inches long. We used a three-quarter drive torque wrench. Certainly on the Audi pulley bolt accuracy was paramount so I would have to disagree with the idea of just doing it up tight. I do have a three-quarter drive torque wrench but I suppose the chances of you being local to me are slim?
West Northants?

But this isn't a crank pulley, it's a hub nut. If it requires 200 ftlb then it will almost certainly be a one piece bearing and the torque is there to hold the nut in place, not place a pre-load on the bearing. In such a case "as tight as you can get" is good enough.

[Penguin45]

It might be useful to find out what the actual vehicle is before making all these assumptions.

P45.

[Young Farmer]

It's a Maxi front hub. I will probably go down the get it bloody tight and a bit for luck route. Don't have to worry about it coming loose as it has a hefty split pin securing it. What about my theory of moving the pivot point a foot away from the hub? will that reduce the amount of torque required by half? would be relatively easy to do as I never throw away old sockets, keep them and weld them on to things that require twisting. Just made a brake adjuster from a split 1/4 " drive socket and a scrap piece of bar.