Jacks under slide out?

[Marc Gregoire]

Good morning: This camper uses 2 jacks under his slide out. Its a Sunseeker 2400 MBS. Is this recommended by FR? Thx.

[Iwritecode]

It's not recommended by any manufacturer and can actually do more damage than good.

[dave961]

X2

I've also heard it can cause damage.

[Rhumblefish]

You'd think it would be a good idea, right? Unfortunately - as nice as it would be - the coach won't be entirely/completely rigid sitting on its suspension when parked and leveled (even with some potential for flex within the structure between the 2-point stab jacks), and the slide isn't part of the rigid frame members that the stab jacks are attached to.

The owers are most likely trying to compensate for the additional lever arm placed on the body with the slide extended. Unfortunately, by mounting *fixed* supports under the slide, every time the coach rocks or twists or flexes in any manner on its suspension, forces applied are actually moving the slide. What that owner has done is attach two fixed supports to the entire coach, using the slide's attachment and extension mechanisms as the flexible suspension point.

Got that? Any force that was going into the class C suspension (and damped by the stab jacks), is now being shared by the slide's mechanism, b/c the slide itself can't move with the coach (like it was designed) unless it deforms (which is also not very bueno).

Bad Idea Jeans.

[Duckogram]

That is a slim rack slide out mechanism which is a rack & pinion. If suspension movement with the OEM rear stabilizers down (as pictured) is a problem then the owner needs to add hydraulic frame mounted jacks.

As for the slide, up and down movement separate from the body will counter torque both drive boxes and possibly twist the drive shaft. or It could transfer the torque to the slide frame and really do some damage.

[Volvodriver]

We've used "slide supports" for years on our fifth wheel. Of course "no" manufacturer of rv's are going to recommend using them. The minute they do they are liable to go to lawsuit city with rver's that have used them like "jacks" and have twisted the slides from here to Tuesday so now "someone will pay".

Dave

[Iwritecode]

Originally Posted by Volvodriver

We've used "slide supports" for years on our fifth wheel. Of course "no" manufacturer of rv's are going to recommend using them. The minute they do they are liable to go to lawsuit city with rver's that have used them like "jacks" and have twisted the slides from here to Tuesday so now "someone will pay".

Dave

They don't recommend them because modern slide-outs don't need them. They are fully capable of supporting themselves.

And it's not even "how" you use them. The problem is that if your trailer starts to sink for any reason (like say a flat tire) then your trailer will start to go down while the support holds the slide up. Then you'll have problems.

[Canadian Eh]

I used a single support at the mid point of the slide where there is a change in the sizing. I only tighten the jack up to hold it in place.

[Duckogram]

Originally Posted by Canadian Eh

I used a single support at the mid point of the slide where there is a change in the sizing. I only tighten the jack up to hold it in place.

Supporting it for what purpose?

[Canadian Eh]

Originally Posted by Duckogram

Supporting it for what purpose?

I find that there is a lot of sway on a 30" extension. I asked the CanaDream rep when we picked it up if there was an issue and he recommended it. I bought and modified two to use on either corner but one wasn't long enough for the rear so I placed one in the middle. I had thought about making a base with some tennis balls that would allow for some movement.

[Dana anderson]

Slide supports Are not sold with your trailer and if they were good for your trailer you know an RV dealership Camping World etc. would want to sell them to you but these are things that you’re only buying aftermarket.
I agree with others that the slide should be able to move up and down because it’s on a track and you don’t want that damaged.

[Duckogram]

Originally Posted by Canadian Eh

I find that there is a lot of sway on a 30" extension. I asked the CanaDream rep when we picked it up if there was an issue and he recommended it. I bought and modified two to use on either corner but one wasn't long enough for the rear so I placed one in the middle. I had thought about making a base with some tennis balls that would allow for some movement.

I have never heard folks complain about “sway” or getting sea sick, or spilling cocktails. Maybe that is because they have hydraulic leveling or are not subject to constant movement. The fact you asked a salesperson when you bought the unit probably indicated that you were sensitive to movement. If that is the case then I understand why you feel the need to address it. So long as you know that you can damage the slide.

[jimmoore13]

So...I use them. Carefully...actually VERY carefully.

We have a Jayco X-213, with a rear bed slide.

This is an extreme slide. It goes out farther than any other slide I know of. It is only about half the wall height high, so there is overall less load bearing surface for the slide to engage with the rear wall of the trailer. The rack and pinion slide mechanism is halfway up the sidewall...not down by the rig's main frame. And it's a JayFeather...very light.

This slide is so high up in the air, that I had to buy these blocks to hold the feet of the supports, which are over 4 feet tall!

I'm 6'6" and 240#. My wife is much smaller and lighter...5'0" and XXX pounds which shall not be disclosed if I wish to continue living.

I used these under the bed slide with two caveats:

1. We setup on solid soils...not hard here in CO where it's dry. Were we to be caught in a downpour, I'd relax the lift on these.
2. There IS NO LIFT on these. I apply just enough pressure on the lead screw to keep them from falling over. I use my drill to extend the lead screw...they are VERY long...but I do the final snug up by hand. I make sure that if I yank hard on the brace, it will skid along the steel frame of the slide mechanism.

So, I agree that they can do more harm than good if used improperly...or if installed for long periods of time over which the rig can settle. They need attention. Most slides should not need them, but if you have an extreme slide...say a full-wall slide...and both cargo and people could add half a ton of weight in the slide under certain circumstances, I'd at least give them a little thought.

Used properly and cautiously, and with stab jacks or leveling jacks solidly in place, they CAN transfer some of the transient load in your slide to the ground, rather than having all that stress be on the sidewall frame and slide carrying structure.

These are the last thing I install on setup and the first thing to go on tear-down.

[Iwritecode]

Originally Posted by jimmoore13

So...I use them. Carefully...actually VERY carefully.

We have a Jayco X-213, with a rear bed slide.

I'm surprised that doesn't have bars that would connect to the back bumper like pop-ups have.

[Canadian Eh]

My first comment is that I'm not confident in FR engineering. Having to replace numerous exterior screws that have pulled through the aluminum capping is just one example.
The slide on the 24C is one of the largest and I can only assume the heaviest since it pretty much goes the full length of the bus and extends 30 inches. The torque that is generated by the weight of the slide along with my weight is only being supported by the two vertical uprights on each end must be considerable. I realize that there is movement in the chassis but I have never noticed any extra load on the screw jack when I remove it. If I get the chance I'll come up with a pad to sit the jack on which will have some compression built into it.

[jimmoore13]

Originally Posted by Iwritecode

I'm surprised that doesn't have bars that would connect to the back bumper like pop-ups have.

Good point.
I have faith in the rig's engineering, but support poles might make sense. OTOH, these would be considerably more robust than those on a PUP, and unlike a PUP, the rack and pinion slide mechanism could be activated without removing the braces...a disaster in the making. Also, unlike a PUP, one doesn't just put a shoulder under this slide to lift and engage the braces. Finally, unlike a PUP where one can use a shoulder to lift the bed, the braces on this slide would probably require lead screws or some other mechanical advantage adjustment to snug them up. All of this leads me to believe the manufacturer would be terrified to trust customers to handle such critical procedures and not wreck the slide. In Jayco's defense, I suspect they chose to engineer the slide and trailer frame to be robust enough to hold up at least until the warranty expires.

[Duckogram]

Originally Posted by Canadian Eh

My first comment is that I'm not confident in FR engineering.

Just for informational purpose; The slide out mechanism and frame structure is not a FR product. Most are Lippert and FR frames and cuts the holes to accommodate the assembly.

[emm-dee]

Set up in a large grass covered CG last week and leveled the MH with two 2x10 boards sitting on HDPE pads under each leveling jack. Along comes a four inch rainfall and the next morning the HDPE pads and first board had sunk enough to disappear. That’s at least a two inch drop.

So, if I had put jacks under the slides what do y’all think would have happened?

[Gill]

It's ok to use them with just very slight pressure,, yes the rv is made to support them , it's when 4 people are sitting at the dining table that "is" the side out,, or when people are in the bed which is the slide out

[Jcape]

Originally Posted by Marc Gregoire

Good morning: This camper uses 2 jacks under his slide out. Its a Sunseeker 2400 MBS. Is this recommended by FR? Thx.

No, don't use jacks under the slides. Yes, all dealers sell them but they won't say don't use them. The jacks will cause you to loose your seal between the slide and the coach body and allow it to leak both air and water (Water is a coaches enemy). They may also void your warranty.