I'm installing a spare tire mount (U-bolt) on the tongue of my boat trailer.


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The tire mount/U-bolt's threads are quite long -- too long for my lug wrench to reach down over the threads to the lug nuts.

How can I tighten and untighten the lugs if the lug wrench doesn't reach?

The lug wrench fits the main trailer wheel lugs too. I'd prefer to only carry the one lug wrench tool with me, rather than add an additional spanner wrench, etc. to my trailer toolkit for the spare tire lugs.

I considered cutting the excess ends off of the U-bolt using a bolt cutter, but I think that would damage the threads and make it hard to thread the lugs onto the U-Bolt in the future.

  • 1
    One minor suggestion: Before cutting down the U bolt, consider how you're going to secure it to the frame. It looks at the moment like if you undid both nuts it would fall off, at that makes for fiddly reassembly assuming it doesn't go missing. You might eat up a bit of length, which is why I say think about it first.
    – Chris H
    Commented Jun 22, 2023 at 8:50

4 Answers 4


Cutting them down to size is about your only option, unless you want to carry a separate combination wrench (spanner). If you want to cut the threads cleanly, don't use a bolt cutter. The way to go is to run the nut down the thread below the cut line. Make the cut as perpendicular as possible using a grinder or hacksaw, then use a grinder or a file to clean up the top the best you can. Leave a small bevel all the way around the top. The last step is to run the nut back off of the threads. This will straighten out any errant threads which might still be out of shape. This should allow you to get the nut back on without any hassle.

  • Of course, use a die instead if you have a tap&die set handy...
    – Jon Custer
    Commented Jun 21, 2023 at 17:38
  • Running the nut or die on and off the thread several times, filing or grinding any malformed thread that's left, will usually help. If you're worried about the cosmetics you might like to finish off with a light coat of zinc paint or similar. Commented Jun 22, 2023 at 6:11
  • 1
    With big bolts and a hacksaw, it's worth working from several sides, so you've gut roughly 1/3 of the way in all round before finishing. Less filing to get a clean edge and a bevel.
    – Chris H
    Commented Jun 22, 2023 at 8:25

I agree with the answer by @Paulster2. However if you don't want to do any sawing, grinding or filing, you could buy a suitable box spanner, for example -

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Product details from that website -

Make all kinds of jobs easier with this double-ended box spanner set. They're often used to remove fittings that are hard to reach, such as deeply set nuts or spark plugs tucked away in a recess.

The box spanners come with a soft tool roll to make organisation and transport easier. A 190 mm extension bar is also included, so you can get the maximum amount of leverage with the minimum amount of force. This means you can remove stubborn fittings with ease or ensure ultra-tight screwing.

Box spanners like these are often used by plumbers to install back nuts on taps, or by boat owners making adjustments to a marine engine installed in a confined space.

  • Thanks! Similarly, here's an Amazon Canada link, for anyone who's interested: amazon.ca/gp/product/B083MV679B/… ... i.sstatic.net/iIPjO.png
    – User1974
    Commented Jun 21, 2023 at 14:02
  • But these "thin metal tubes roughly hammered into hexagonal shape" will not survive any amount of torque for long. I for one wouldn't want to depend on one of these to get my spare tyre from the trailer after the nuts have lived in road conditions for any amount of time.
    – arne
    Commented Jun 23, 2023 at 9:14

The answers from Paulster2 and HandyHowie both provide viable solutions, but if neither option appeals to you, make a spacer.

Remove one nut and find a short length of pipe or metal conduit that will fit over the threaded portion of the U-bolt without too much slop. Half-inch (trade size) electrical conduit might be perfect. Cut the pipe or conduit to a length that leaves enough threaded rod exposed to accommodate the nut without interfering with your lug wrench. If the nut does not engage well with the spacer, use a washer. Repeat on the other side.

Or if theft or tampering is not an issue in your area, use wing nuts instead of hex nuts and skip the lug wrench altogether.

  • Leaving the lugs long also allows for stacking on a second spare wheel in the future. Perhaps a thin space saver wheel as a last-resort.
    – Criggie
    Commented Jun 22, 2023 at 0:34
  • The advantage of a spacer is that it ensures that the (hub of the) wheel is clamped firmly, rather than simply the inflated tyre being compressed against the frame. However loose spacers have an unfortunate habit of losing themselves... Commented Jun 22, 2023 at 6:15
  • @MarkMorganLloyd: using a nut above the spacer but below the wheel helps retain the spacer and acts as part of the spacer length. Commented Jun 22, 2023 at 15:56

Like almost everybody else, I defer to Paulster2's answer: a U-bolt is a stock item made to one of a number of sizes, none of which was quite right for the application.

However: is the wheel dished asymmetrically, and does less thread protrude if it is turned over?

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