Levelling with Scissor Jacks

Nvr2loud wrote:
I know I'm going to get flamed, but I replaced the (4) OEM single arm stabilizers on my Trail Cruiser 30 ft travel trailer with (6) 24" scissor jacks. I experimented with lifting excessive weight with the scissor jacks and found that it is easy to lift the trailer wheels off the ground without frame bending.

During testing I have gone to the extreme and used (1) jack on the back corner to lift the wheels right off the ground. I first used blocking on the front corner and took the weight off the tonque jack to prevent damage to that jack. Then I used a cheater bar and cranked that one scissor up until the wheels had enough space below them to slide a 2x6 board under. The trailer wasn't even visibly twisted. Both doors opened and closed without an issue, the only visible sign inside the trailer was the bathroom door did not latch closed unless I pulled upwards on it slightly.

Keeping in mind that I'm just testing, I used all six scissor jacks together and picked the entire trailer up off the wheels and tongue jack without a problem. It is perfectly straight and level without bending.

My first two trips out camping with the new setup went perfectly. I used three jacks on the low side to level, then used the 3 jacks on the high side to stabilize. On one site I needed to life about 3 inches to level, and the weight was nearly off the wheels, so I jacked slightly higher and put a 1x6 board under the wheels and lowered back down. I am confident that with care, and proper placement, the scissor jacks can be used for lifting.

I would not lift again like the testing phase, I know the trailer is not designed to be lifted from one rear corner and supported only by a stand on the front corner and the opposing wheels, but it did just fine during the test.

One more point could be made. All trailers give somewhat when the stress point is changed or increased at the same point. The OP is technically a bit wrong when he states that "no visible twisting occurred" or "it is easy to lift the trailer wheels off the ground without frame bending". I know he did re-qualify that by stating that the bath door was skewed.

The TT camper body-bend can easily be seen by getting on a ladder, and eye-balling down the rain gutter from one end, before and after. A 5vr is not as simple because the gutters may not be mounted straight and level. For experimental sake, a string line could be stretched alongside the length of the trailer with periodic before-and-after marks made on tape placed beneath the string. But the TT gutter trick is quick and easy if a stool/stepladder is available.

I would encourage anyone with a shred of curiousity to do the simple rain gutter sight-down observation, before and after their jacks are down. It is as accurate as sighting a rifle. It is possible to directly view exactly how much bend a camper has, with no guessing.

On my own, I happened to look down this gutter when I noted the gutter drain-water spilled over the camper side-wall when the end-jacks were doing any lifting at all. In other words the gutters, and I assume the camper body, are straight when the rig is supported by the wheels. But any lift on either end always causes a slight sway back not easily observable any other way.

Since the gutters are all of 3/8 inch deep, neither rain water, nor A/C condensate, ever gets to the end drain spouts, but merely spills over the side, when the jacks are doing any lifting. On my camper, when the jacks are seriously extended to lift more than an inch, the sway back is a good 3/4 inch on the weak slide side, because of the total lack of solid supporting wall on edge, I suppose.

To partially compensate, I place my tire service jack under the low side, very near the wheels, when leveling and lift the low-side camper body by the frame near the wheels to level to needed position. Only then do I extend my stab jacks very lightly (no more than 1/2 inch lift) to minimise any downward bounce from foot traffic inside the cabin.

Another way to level side-to-side would be to drive up on planks on the low side, but I am too lazy to do it that way. The hydraulic service jack is the first thing out of the storage bay anyway and it's use just makes bay access easier. Also, another advantage, the service jack has a wide steady base and its use greatly prevents fore/aft rocking as it partly lifts the frame off the spongy springs and provides a zero-movement top "pyramid" point very near as good as solid blocking.

Wes
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