Leveling Scissor Jacks

nickthehunter wrote:
I am not an expert on the matter, but putting a support pillar way out on each end of a beam without knowing just how much load that beam is capable of supporting is a bad idea. Stabilizing and leveling are two way different concepts when it comes to how strong a beam needs to be.

I suppose you could define Stabilizing as taking SOME of the load off the tires/leaf springs such that movement inside the RV is reduced when someone is walking around or when the wind is blowing (aka: Makes things more stable inside). Whereas Leveling could involve taking ALL the load off the tires/leaf springs with the primary goal of making the RV LEVEL inside (and secondarily making it also more stable since the load will be off the tires/leaf springs). When Leveling in this manner, it is possible that some of the tires could be literally off the ground and the weight on that side/corner will be supported wholly by the leveling jack.

The official jack point on the rear (in a Class C) is on the axle itself. I would need to look underneath my RV to see exactly how this load is applied/distributed to the frame beam, but I believe it is somewhat spread across via the leaf spring. If I were to install a scissor jack on the beam itself AS CLOSE TO THE AXEL AS POSSIBLE (probably within ~3') I wonder if this is okay. Thoughts? Have any of you done this?

My gut feeling is that I would NOT want to install a scissor jack for leveling (lifting) "way out on the end of the beam" as that is probably ~8' behind the axle and that seems like it would put maximum stress on the frame beam. But would a scissor jack ~3' from the rear axle be okay?

Doing some searching online....
https://www.youtube.com/watch?v=Hfg70RzvaIk
(jump to 7:43 for an installation image from the manufacturer of one particular RV as ONE data point...)

or this video at ~1:20 shows leveling jack installed about 3' behind the rear axle...
https://www.youtube.com/watch?v=93dNz8Ft-tM

Or this one at 5:50 and 7:20...shows rear jacks ~3' behind the axle.
https://www.youtube.com/watch?v=1U0Igk0ZSa0

Those above videos seem to be leveling systems installed by professionals. Based on those, it seems like installing rear jacks ~3' behind the rear axles is likely okay. Anyone have more to add?

Thanks!
Chris

I am not an expert on the matter, but putting a support pillar way out on each end of a beam without knowing just how much load that beam is capable of supporting is a bad idea. Stabilizing and leveling are two way different concepts when it comes to how strong a beam needs to be.

Mine are mounted at 45 degrees on my TT. The jacks have so much play in them that I doubt it really makes any difference in performance so unless it's easy to do , I wouldn't mount them that way.
FWIW, I would go with a heavier jack. Doing so will cause it to be more stable and oftentimes they have dual bearings (for both extend and retract) and work a lot smoother over their life. You can also crank on them harder before the jack screw distorts.

Side note: My idea when I was considering doing this in the past was to also add this to my RV...

https://www.amazon.com/dp/B08HYKQPBQ

With this, you could have your RV leveled in just a minute or two!

Suggestion: If you do this, I would suggest that anytime your RV is jacked up you place the impact wrench (or whatever you use) on your driver seat or by the gas pedal so that you never accidentally drive away with your jacks still down!

Good luck!
Chris

Not sure what you mean by "45 degrees". Jacks need to be holding weight vertically straight up and not at an angle.

Perhaps what you mean is that your idea is to mount them so the access up/down adjustment port is not pointing straight out towards your sides so that they are less visible(?). That is fine but probably not necessary. It might be harder to mount them to the frame if you try to angle them that way. But if you did, as long as they are securely attached to the frame it would be okay.

If the purpose is to use these to level a few inches here and there while at a campsite, it should be fine (Pending input from others about my question above regarding mount location and potentially bending your frame). But you will want to make sure the weight carrying capacity of whatever jacks you use has plenty of margin and you shouldn't go underneath your RV with just these jacks holding it up.

-Chris

Note: Those jacks are rated at 5000lbs each, not 10,000lbs each.

Your rear axle is likely close to 9000lbs. So with 2 of those jacks in the rear (5000 + 5000 = 10000) you will be technically ok, but for me I would want more safety buffer/margin. For example, here is a 9000lb jack that actually costs less than the ones you mentioned:

https://www.amazon.com/LIBRA-Trailer-Stabilizer-Leveling-Scissor/dp/B08LTW81BS

With 2 of these in the heavy rear you will have lots of buffer (extra strength/margin).

Safety note: I would never climb underneath a lifted RV with just a scissor jack holding it up. Anytime I go under my lifted RV it has a bottle jack and multiple jack stands as backup.

I like the idea of what you are doing and considered doing it myself on my Class C RVs. It seemed like there was some easy spots in the rear to mount scissor jacks to the frame, but it was never clear to me if that spot on the frame was a smart/valid location to lift the RV at (...Can the frame BEND if jacked up in the wrong spot and do damage?? Anyone know?). On my 30' RVs, I could mount scissor jacks on the frame but it was about 3-4 feet behind the rear axle. Anyone know if that would be okay, or would it put too much stress on the frame?

Unfortunately, I could not find a good spot for scissor jacks on the front axle/area. Again it would need to be on the frame and about 3' behind the front axle. Anyone know if that would be a bad idea? Might be a moot point, as it didn't seem like there was enough clearance on the front to permanently mount scissor jacks.

Now that I'm thinking about it again, maybe it would be reasonable (at least for me) to mount some of these scissor jacks on just the rear (Pending input from others on frame bending...). I recently went camping at a rural campsite that was too sloped for my leveling blocks to get me level (I was off by probably 3-4 inches front to back). Having jacks could have helped. With them in just the rear, I could either back into a spot or pull into a spot depending on which way it was sloping and then the jacks in the rear would come in handy. Hmmm.....

OP: Please let us know if you mount 4 jacks on your class C and if so let's see some pictures. Maybe you will encourage me to give it another look.

Happy camping!
Chris

Not sure why you read that - Perhaps inadequate frame support? A scissor jack is a type of leveling jack. Why 45 deg? If 10K rating is adequate you'll need larger rating for 45 deg.