power leveling jacks

It really depends a lot on the type of jacks you have. I have the HWH series 200 kick down jacks and have rolled forward several times. One time I pulled into a campground after dark and could not tell how unlevel the site was and rolled backwards and jamed the rams into the dirt and grass and they would not fully retract until I cleaned and lubed them. It is quite scary when a 16,000 lb MH rolls of the jacks. They ARE designed to roll off with no damage.

I had a side load on one of my rear jacks once and it did not do any damage but it was enough force to let the hydraulic fluid leak out.

All sound like very logical explanations and they make sense. But why would the engineers, the same folks that tell you not to raise the wheels off the ground, engineer and attach them in a way that you can? More to the point, allow them to lift the coach off the ground but be under-engineered in way to allow for lateral failure. And why does the auto level feature ignore this "rule"? I've had mine lift off the ground in auto mode. Hydraulic rams for the most part aren't terribly expensive or complicated. Beefier ones could be installed pretty easily to prevent this type of failure.

Effy wrote:
Just curious, I've been in situations where my tires were off the ground and never had an issue. I mean where is the RV going to go? It's still on the ground via the jacks. The jacks have a footprint about equivalent to a tire. The jacks would have to laterally collapse and then it would drop to the tires anyway. I seriously doubt there is a risk of it skiing down a hill on the jacks. And they will only extend so far thus inhibiting you being on a step enough incline for an issue to occur. Sorry I just never understood the "tires have to be on the ground" thinking. I see lots of folks at CGs all the time with tires off the ground. I've never seen an issue where it took off because of it. Not trying to be crass, I've just never seen or heard of an actual issue. If you use your jacks, and then add boards under your tires, what's the point of the jacks? You might as well just have leveling boards and drive up on them.

It depends on the type jacks. If you have HWH kick down jacks and you lift the weight of the motorhome off the tires, the motor home will then shift FORWARD as the jacks are forced to flip on the Kick down pivot point. If the slope is great enough, if you lift the tires off the ground, the motorhome CAN slide that downward slope a little bit and then the jack pistons usually bend a little. Then you cannot get them fully up. You last statement is kind of lame. Which is easier--
1. Putting extra boards UNDER the jacks to get more lift?
2. Or getting out and adding a slope to then attempt to drive onto a bunch of boards?
I think the answer is obvious. BUT, you NEVER lift tires off the ground. ALWAYS install support boards under the tires(front) if you do that. The reason is, IF one of those jacks developes a leak or starts a retract, that corner will then come down and put a stress and possibly harm the frame or pop or crack a windshield if in front. With boards under the tires the boards will support that corner if a jack fails. Doug

Hikerdogs wrote:
The front tires can be off the ground with no problems. However the rear tires should always maintain contact. In most cases the parking brake is either at the rear wheels or on the driveshaft. Should the rear tires be off the ground there's nothing other than the jacks to keep the motorhome in place. Should one or more slip there's a good chance the motorhome will move.

If the motorhome moves there's also the chance that one or more of the jacks can get bent. They do have some lateral movement to compensate for uneven ground, but there's no provision for longitudinal movement. The motorhome could move forward or backward an imperceptible amount and still bend a jack cylinder or its mount.

This is a good explanation and yes it can be very real. Most notably one or more jack bending and possibly causing a problem when retracting.

Also. make sure you know if your slides should go out before or after leveling. This seems to vary by coach but many want the slides out before leveling and the coach at ride height.

Effy's post... LOL....

Jacks lift the rig off the ground no problem. The problem is they don't handle side force. The rear wheels limit or prevent the this. The side force puts the jacks in a bind and they will not retract. Worst case, the ram bends and will never retract. It takes some heavy equipment and $$$ to get the rig high enough to get under it to remove and replace the jacks.

I have seen this happen more than once.

The people who write the manuals know what they are doing.

The front tires can be off the ground with no problems. However the rear tires should always maintain contact. In most cases the parking brake is either at the rear wheels or on the driveshaft. Should the rear tires be off the ground there's nothing other than the jacks to keep the motorhome in place. Should one or more slip there's a good chance the motorhome will move.

If the motorhome moves there's also the chance that one or more of the jacks can get bent. They do have some lateral movement to compensate for uneven ground, but there's no provision for longitudinal movement. The motorhome could move forward or backward an imperceptible amount and still bend a jack cylinder or its mount.

Just curious, I've been in situations where my tires were off the ground and never had an issue. I mean where is the RV going to go? It's still on the ground via the jacks. The jacks have a footprint about equivalent to a tire. The jacks would have to laterally collapse and then it would drop to the tires anyway. I seriously doubt there is a risk of it skiing down a hill on the jacks. And they will only extend so far thus inhibiting you being on a step enough incline for an issue to occur. Sorry I just never understood the "tires have to be on the ground" thinking. I see lots of folks at CGs all the time with tires off the ground. I've never seen an issue where it took off because of it. Not trying to be crass, I've just never seen or heard of an actual issue. If you use your jacks, and then add boards under your tires, what's the point of the jacks? You might as well just have leveling boards and drive up on them.

Maybe.
We were at a RV park in Tuscaloosa (i think) and the sites looked pretty level.
But our rear tires tried to come off the ground when we autoleveled.
Many others were doing the same.
We had to put a couple boards under the tires and manual level to make sure the rear tires stayed in contact.

as long as its level slides are ok as Gjac said keep your tires on the ground