X4 Torque Multiplier

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Function of X4 torque multiplier
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1-1/2" drive torque multiplier at work
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1-1/2" drive torque multiplier at work

One of the issues that you have to face up to if you are to work with heavy equipment is the issue of fixing it. To be sure, many things are manageable with traditional automotive wrench sets. However, when you start having to work on the bottom sides of large machines the story changes. The bolts get very large and the torque settings become amazing.

The most obnoxious thing that most people see are lug bolts on trucks. The Budd wheel nuts should be tightened to 450 foot lbs of torque, but may require a 1000 lbs or more to loosen. If you have to do this by hand with brute force, about a 6 foot long handle on the lug wrench will do the job, or a 1 inch drive impact wrench as most will produce something over 1000 lbs. of torque.

When you must deal with undercarriage parts on a large bulldozer, or cutter bit bolts and the like, you will need to reach 4000 to 6000 foot lbs of torque or more. A 20 foot handle on your breaker bar is impractical, and the 1" drive impact wrench is useless.

You have some choices, but the time has come for 1-1/2" drive tools. One must have is a 1-1/2" air impact wrench. The low end ones are good for about 3000 lbs torque. This will get all but the most stubborn bolts that you might find on a large bulldozer. But there are those that won't yield to even a 1 -1/2" impact wrench. There is also a 'high end' 1-1/2" impact wrench on the market that puts out about 8,000 ft. lbs of torque, however it weighs 75 lbs and just about needs 2 men to handle it. The low end ((under $2,000) impact wrench for 1-1/2" drive usually weighs around 35 lbs and is sort of a 1" drive wrench on steroids. If you are a big guy you can use it fairly easily.

If air is not available or the big air wrench won't take it, you have to resort to 'doing it by hand'. The solution is one or more torque multipliers. I usually use 2 of them and stack them. They are typically about a 4:1 ratio and if you stack them you get a 16:1 gain. My favorite combination is a 1-1/2" x4 multiplier stacked with a 1" torque multiplier. The latter has a 3/4" input side and usually I use a 3/4" ratchet to run it.

This gets most things, and yes, you really do need 1 - 1/2" drive. On at least one occasion, I had only a 1" drive impact socket of the size I needed and was using a 1-1/2" to 1" impact adapter. With the help of a cheater pipe on the 3/4" ratchet, I twisted the adapter off, only to find that Proto doesn't warranty adapters against breakage. They figure adapters are only for light duty, and if you twisted it off, it must not have been light duty. The 1 - 1/2" drive stuff is kind of spendy, but there is little choice if you are going to work on the 'big stuff'.

Update: September 2006

The photo shows just one large X4 being used in combination with a 3/4" drive Snap-on ratchet. This combination is turning a 4" nut which was sufficiently reluctant that the 1-1/2" drive impact wrench wouldn't turn it. Notice how the handle of the X4 is resting against the machinery. If one were using a short handled ratchet, then it would be necessary to stack the X4's to get the torque. Here it wasn't just a matter of breaking the nut loose which could have been achieved with a hammer wrench, but the threads were burred up and it was a nylock nut so it took a steady heavy pull all the way off. Impact wrenches work pretty well to hammer something loose, but when the threads are just tight it's really difficult particularly when everything is so heavy. The socket is in the range of 20 lbs, and much of the impact of the impact wrench is absorbed.

One needs to thoughtfully contemplate and calculate the torque involved. Here that ratchet has close to a 4 foot handle, and assuming that a man can pull his own weight you are looking at up to 200 lbs force on a 4 foot handle or 800 foot pounds input multiplied by 4.3 or over 3400 lbs output. The particular X4 in use here is the JM1500 which is rated to 4000 lbs output. Practically speaking with a ratchet like that you are unlikely to over torque that multiplier, but a real gorilla might. For my part, I have a 3/4" drive torque wrench with a similar length handle that registers up to 600 foot lbs of torque and my eyes are bulging a bit if I use it very much at the maximum setting, but that doesn't mean that this torque multiplier couldn't be broken with this ratchet.

The alternative to the brute force approach here would be to stack the torque multipliers putting a small one on top of the one shown here and using a 1/2" ratchet.

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