Levelling with Scissor Jacks

So let me get this straight - you think my sentence there means I am worked up???.... man you must run at 1/10 normal speed.... just kidding, keep your shorts on ..... lol :)

But the answer is um cuz I almost never respond to this stuff.. and this time got a wild hair for whatever reason to say something that seems endemic to 2 out of 3 posts I seem to read on boards like this, which is why i dont read boards like this since the signal to noise ration means way less answers than flames and sarcasm. I only answered your post because this blog auto sent an email to be the someone had responded... I thought it was just spam initially.

baylonjay wrote:
first off - why is it that some always have to be so definitive in their proclamations,

Um, why start out so worked-up on a thread that hasn't had a new post in nearly 2 years?

first off - why is it that some always have to be so definitive in their proclamations, as in i am right, you are wrong, and you are engaging in stupid foolish behavior ?? (this is not to say at all that some do not do stupid foolish things, but this thread initiator seems to not be that type of stupid/fool)

Here is what I do, and it is not damaging the trailer one bit!

lift the trailer right under the frame in between the two wheels / axles in the middle (as you would to change the tire) with an appropriate bottle jack to get it level (agree that any kind of scissors jack will not be good at all or proper / reliable to actually raise/lift a trailer)

Once it is raise with the bottle jacks - lower and tighten two scissors jacks either mounted right on the axles with heavy u-bolts. or welded / bolted to the frame as close to each axle as possibe. If you want belt and suspenders - leave the bottle jack in there with the scissors jack.

Once this done - I then lower my frame mounted front and back stabilizer jacks firmly to the ground.

This gives me 8 points of load bearing on each side (9 if you leave in the bottle jack) - and of course the tongue jack in the front. This gives the frame as much support in the lifting phase, and MORE support once all the scissors and stabilizers are in place.

And of course the last point brought up by one post - the by far most stress ever on a TT is when you are driving it... this is what it really needs to be designed for - since the dynamic fatigue and stress are FAR greater and less balanced than almost all the leveling schemes I have seen in this post. Aluminum and composite construction is used for two reasons - it is very good with the dynamic fatigue loads on the road... precisely because it it lighter while being just as strong as solid plywood or aluminum sheet.

As an update....

Please remember that I have been experimenting with a travel trailer that does not hold much value, I have pushed the frame to the limit and observed the results. There have been some great responses (most against what I have done) and a lot of info has been provided for all readers.

I hope to "learn the hard way" on my low value trailer. I just upgraded my tow vehicle and will be getting a newer trailer after this camping season.

From the axles back the frame of my travel trailer is not intended to lift / jack and will flex a lot... that is when the bathroom door skews, the fridge door makes horrible noises, and the trailer makes noises when jacking. I will not lift it at the back of the frame at all. I removed the scissor jacks from the back corner and put them directly behind the tires very close to the axle plates. Now I have scissor jacks on either side of the tires and at the front corners. I have a-arm stabilizers at the back corners. I will duplicate this set-up on the next trailer.

I park my trailer, check side to side level and drive-up onto my leveling boards. Then I disconnect from the truck. I level fore-aft with the tongue jack. I lower the scissor jacks on either side of the wheels and fine tune the level side-to-side. Then I lower all remaining scissor jacks and stabilizers and just barely take the weight of the trailer. Solid, stable, and level.

I can easily lift a pair of wheels off the ground with the scissor jacks to either side of the wheels but have not needed to do so. I would use that method to change a flat tire since the jacks are very close to the axle plates (I couldn't bend the frame or plates there if I tried, and the plates are actually seam-welded to the I-beam frame which was a big surprise to me)

To sum it up....

The trailer CAN bend depending on where it is lifted from, lifting at the back of the frame actually pushes the frame upwards taking the floor with it. The walls are too rigid to bend with the frame, so the floor actually gets a dome shape to it if lifting from the back. If I cared about my trailer, that would send shivers down my spine. I imagine that it would be very easy to pull the floor right off the wall and cause SEVERE damage to the trailer. I have had zero problems lifting from either side of the tires or from the front scissor jacks (but there is no reason to lift with the front jacks anyway, since the tongue jack is right there)

I have used the front scissor jacks to hold the weight of the trailer and then raise my tongue jack and put blocks under it for very uneven sites then put the weight back onto the tongue jack.

There is a lot of movement from scissor jacks, and they look like they could easily collapse sideways with too much pressure on them.

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
...

wow, just signed up and was browsing when i seen these postings. i believe the guy who pointed out that leveling jacks as per the (manufacture) state clearly they are not for lifting laid it out pretty clear! i work at a hd truck and trailer shop and we do a ton of rv sus and frame work including re-working frames to accomodate stress and we (as a rule) never lift from front to back as
most modern frames are made from 16 gauge 12 guage max material and never (t100) their for they (will) flex and if you have a hardwall trailer you will cause damage maybe not today maybe not tommorow but it will happen. if your changing a flat the best rule is to jack as close to the inside of the wheel as possible and if their is no lifting points use a block of wood to help prevent dammage to the axel tube. usng your stabalizers as a safty measure is not a bad idea. i cracked the wall of my tin sided pioneer 180ck by doing just that and it was much more rigid then whats out their now.

Did the Original Poster state what kind of trailer he owns?

Boy, some of you guys sure do want to argue. I appreciated the posting, I believe the original poster did state he changed the stabilizing jacks to lifting jacks.

It really depends on the trailer construction. I have a 25 ft ultralight without a slide. It shares the same frame section and suspension as a 32 ft version that weighs almost 2000 pounds more. Manufacturers save money by using similar components. That said, I have found my trailer to be very stiff when using the stabjacks. I really don't hear the creaking others have described. I really don't load the jacks that much, just enough to center the bubble when it is on the center mark, but off to one side and bit. I think there are so many variations of trailers and types of construction, each owner should evaluate what they have (do some research) and decide what they can do with what they have.

Heavy duty Bal 5K and 7.5 K LBS jacks are no better than any other rated jack period. The Screw attachment washer is the only thing that matters and bal's design is the same as the rest. I've broken Bal stabilizers on my Toyhauler before. Best to get close to level and just take a bit of load off the springs or the washer will fail. I used to have more problems and damage by dragging the darn things going off road.

I have posted pictures in the past of trailer frame damage… there is no reason to repost them to shoe how light duty they really are… I have also stated many times my friends weld shop does frame repairs for several local RV dealers and they supply him with plenty of work, many I have seen in his shop for myself…

you don’t need to be a engineer to see the damage and you don’t have to be a expert to know how the industry shortchanges the construction of these things and makes up for it in glitz… I have been around them for to long…

The quality of the frames they design for RV’s are on par with the quality of tires they put on them… we have read enough about tires… like the tires most of the time you won’t have a problem…

There’s no need to take my or another’s word on it, every related mfg is consistent on this… it doesn’t take a genius to research this on your own…
but you do need to have a open mind and apply a little commonsense…

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Approx. 2 years ago, our family went from owning our own house to being houseless - we sold our sticks and bricks and bought a toy hauler to call home while we travel the country. In the past few weeks, we have gone from being houseless but with a home (our toy hauler), to being homeless. Our 5th wheel has suffered frame failure. And it’s not just our frame that is experiencing failure, I believe that there is a failure of the RV community to realize that this is a problem that happens to 5th wheels all too commonly
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We owned a 2005 Prowler Regal TT (34?) with a Lippert frame. The cross members collapsed like paper and the frame bent sideways at the axles.
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I am lowering landing gear and notice that the drivers side skins are just torn up and cracked…You got it front of frame broke again….
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1000 miles from home. Broken RV frame, 2010 model.
I have weighed the RV and it is not overloaded. I actually even lightened it for this trip.
I pulled into the campground and walked in to the office. Looking back at the RV, my jaw dropped (as did my stomach) when I saw this
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I have a 1998 Wilderness 31ft 5th wheel and was getting ready to leave the campsite yesterday when I noticed the passenger side rear tire had a gap of 1" between the rear tire and front tire and the drivers side had a gap of about 4". Where the rear shackle is welded to the frame broke (the frame not the shackle) and had caused the axle to shift. Right now the RV is about 2 hours from home stranded at the campground
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we ended up having the area fixed by a welder that does a lot of trailer frame repairs. so you might want to take a look at your frame
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the welder said they see weld failures all the time and this failure was probably from making sharp turns and flexing the rear axle and the welds that failed were done on the inside of the I beam > the welder also said they are repairing more and more frames
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And none of these claimed to use corner jacks for lifting or leveling…

There are hundreds if not thousands of post about frame and frame failures in many forums including this one… many if not most of the problems are a combination of poor quality and user abuse and much of the user abuse is done willingly and against conventional wisdom and advise, aided by encouragement from others willingly doing the same thing…
Usually accompanied with the popular forum phrase “ sure you can, I do it all the time”…