Installing a New Jack on a Construction Trailer.

[Don52]

My customer had a construction trailer that had a pitiful swivel jack on the side of the tongue. At some point someone tried to use the jack when the trailer was loaded and bent the jack and the angle iron of the trailer that it was attached to. The trailer was drilled for a conventional jack but unfortunately the cross brace that supports the break away chains slightly blocked the hole for the jack. The mission was to cut off the cross brace and shorten it so that it could be welded further forward, to clear the jack hole, so that we could install the new jack. I supported on side of the trailer on jack stands on one side and used an engine hoist to raise the other side to an angle of 45 degrees so that I could get under it more comfortably to work on it. I used an abrasive cut off wheel to cut off the fillet weld on the cross brace and then I cleaned up the rusty metal of the cross brace and trailer and MIG welded it back in place again. Two welds were overhead and the other welds were halfway between vertical and horizontal.
The original cross brace was only welded on the bottom. When I replaced the cross brace, I welded it on the side as well as the bottom of the angle iron to make it stronger. I painted just the tongue and installed the new jack.

Don

[Don52]

And here are the rest of the pictures.

[FernTJ]

The blocking under the trailer looks a bit sketchy but you got the job done all right.

[Don52]

It is actually a little more secure than it looks. In picture #4 the vertical 2x4 is sitting in a pocket in the bottom of the trailer -- it has nowhere to go. The 2x4 is a two force member so the line of action is on its center line. This means that the 2x4 doesn't rely on friction to support a side load on either the top or the bottom of it. The 4x4's are a different story because they rely on friction on the bottom where the make contact with the driveway. My assistant put them there and I didn't object because they did no harm, but I agree that they aren't very robust. Although I would never rely solely on it, we did leave the engine hoist in place and it could easily support the entire load if you intentionally knocked out the 2x4.

[fencemaker]

How long did that take?

[Don52]

How long did that take?

It took the two of us six hours.
Removing the old jack and installing the new jack was the easy part.

[kiwi]

It is actually a little more secure than it looks. In picture #4 the vertical 2x4 is sitting in a pocket in the bottom of the trailer -- it has nowhere to go. The 2x4 is a two force member so the line of action is on its center line. This means that the 2x4 doesn't rely on friction to support a side load on either the top or the bottom of it. The 4x4's are a different story because they rely on friction on the bottom where the make contact with the driveway. My assistant put them there and I didn't object because they did no harm, but I agree that they aren't very robust. Although I would never rely solely on it, we did leave the engine hoist in place and it could easily support the entire load if you intentionally knocked out the 2x4.

You have an assistant? Lucky....
Nick

[cope]

Don, your repair job reminds me of the old saying, there's never enough time to do it right the first time, but there's always time to do it the second time. Very nice work.