I am attempting to repair a shattered housing mandrel on my Husqvarna riding mower. I have it largely disassembled however I am facing a common problem: a stuck nut on a piece that is moving. The only leverage I can get is with the tool on the nut and the blade below. I have done some reading and seen suggestions on heating the nut but I do not have an acetylene torch handy so I'm looking for good advise. I am familiar with some of the more obvious techniques; such as whats proposed here: How to loosen a nut when bolt and nut move together?

Any advise?

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  • 3
    Are you sure you're turning it the correct way? Could it be left hand threads?
    – Tester101
    Aug 30, 2014 at 21:11
  • 1
    (continued from above) re-tightening the nut. The big advantage of a tool like this is that it applies the anti-rotation force in the same plane as the pulley and nut that you are trying to remove. Even better than dropping a steel rod through the hole in the pulley because if there is any distance from the pulley to where such steel rod engages some unmovable object there is risk of bending or cracking the pully.
    – Michael Karas
    Aug 30, 2014 at 22:14

3 Answers 3

  1. See the holes through the pulley face? Insert the heftiest screwdriver, steel rod, or what-have-you which fits and rest that against the biggest thing below it which does not turn. Use that to prevent the pulley from turning. Probably, you'll have to dedicate one hand to that while loosening.

  2. Look carefully at the exposed thread. The photo is not clear enough for me to be sure, but it looks like it might be reverse threaded. So to loosen, apply force clockwise (as seen looking down the bolt). Unless it turns out to be conventionally threaded, then counterclockwise loosens.

  3. A ratchet and socket set like this will last decades. 3/8 inch drive is a good compromise between cost and durability/strength. I still frequently use my Sears Craftsman hand tools accumulated in the 1970s and 1980s. The few failures I have had were cheerfully replaced (for free) years after I bought them.

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For a nut so far down the shaft as that, a deep socket is called for. Those can be purchased individually at larger stores. Or sets of deep sockets at most stores, though that might be spending a lot of money for items you may never use. enter image description here

If the nut was tightened well, the ratchet handle probably will not provide sufficient torque. Simply extend its length by slipping a pipe over the handle, or attach Vice Grips, channel locks, etc. to increase lever arm—and therefore torque with the same pressure.

It could well be a two person job to initially loosen the nut—one to prevent the pulley from turning and one turning the socket handle with one hand and providing counter-torque on the socket with the other hand. Counter-torque is often needed when the socket does not provide enough stability to keep the socket aligned with the nut.

  • 2
    "Slipping a pipe over the handle of a tool" shows total lack of respect for your tools. The handle of the ratchet is designed to a strength to which the tool can provide reliable service. If the tool is not up to the job as-is then get a better tool. They specifically make beefier sockets and socket breaker bars for this reason. If a 3/8" drive is not going to cut it move up to a 1/2" tool set. Likewise if 1/2" is not enough they do make 3/4" drivers as well.
    – Michael Karas
    Aug 30, 2014 at 22:00
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    @MichaelKaras: I disagree. Sears Craftsman at least, significantly overbuilds its hand tools. I have used a 3 foot pipe over an 8 inch ratchet handle to generate 240+ foot pounds of torque. The pipe was munged a bit, but the ratchet and socket were undamaged and are still in use.
    – wallyk
    Aug 30, 2014 at 22:07
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    I didn't say that you may not be able to make it work. However one of the earliest lessons any craftsman learns is to use the right tool for the job. Doing otherwise leads to safety issues and total lack of respect for your tools. Period.
    – Michael Karas
    Aug 30, 2014 at 22:24
  • 3
    In an ideal world, yes, we'd all have the right tools for every job, but sometimes, for whatever reasons, you just have to improvise and do the job with the tools you have to hand. Is it ideal? No, of course not, but it can still be done with care.
    – John
    Sep 2, 2014 at 21:39
  • Thanks for the pipe idea. That worked great. One thing I did to lift the one side of the mower to get underneath was what I did was use dolly cart and pushed it underneath and lifted up the on side of the mower. Then under the tires I pushed metal car lifts I had. Made it very easy to get under to change the blades. When I was down the one side I used the cart to lift it up and pulled out the lifts then I did the same thing on the other side.
    – George
    Aug 9, 2017 at 19:12

Screw an old v belt around the pully to a 2X4 or chunk of wood as tight as you can; I put wooden shims and screwed them into the inside diameter, and the belt to the shims to make it super tight so the pully wouldn't move. Then just attach the wrench and whack it as hard as you can with a mallet to knock it loose. It worked for me when nothing else would.enter image description here


Is there anything under the pulley that you an get any purchase on the bolt to stop it rotating while you undo the nut?

If you have (or have access to) an impact wrench, they can often shift stuck nuts that seem to require an inordinate amount of force with a socket or spanner.

  • Only the blade; the housing mandril is the cylindrical object beneath the dark wheel; under that is the blade. I can grab on as it is only a lawn mower blade but I find even with the leverage it is difficult.
    – Gedalya
    Aug 30, 2014 at 19:55

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