additional stabilizer jacks

[bob48]

i have a 3685 montana 5th wheel. when using only the front hydraulic jacks the trailer tends to move as if still on the suspension. i am thinking of adding additional jacks to correct this. has anyone done this and what would be the best location for these jacks.
thank you

[Pull Toy]

If you use only the front jacks, you are still on the "live" suspension. In order to stabilize you will need a minimum of four points of contact under tension to the ground to lose that rocking feeling.

As far as location goes, most campers add jacks to the rear of the back axle. Many rigs have jacks at the back corners by the bumper, if you go this route with jackstands, or permanently mounted jacks, I've found that worked best for me was to get close to level, but nose down. Deploy the rear jacks, then use your front jacks to rock the weight back onto the rear jacks. The idea is to basically "lift" the weight partially off of the axle springs. Depending on how stable you want to go, I've also seen people with tripods under the 5th hitchpin, and special wheel chocks that wedge between the front and rear tire at the midpoint (3:00 / 9:00) that, when tension is applied, acts like a parking brake, and keeps the wheels from "squirming" independently of each other.

Our current rig has six way hydraulic leveling, but even with that, after a day or two, we get some movement as thing settle. The only sure way to eliminate all motion, is to jack it up until all four are in the air, and put cinder blocks everywhere... kinda like a doublewide...LOL!

Good Luck!

[bob48]

thank you for your reply, we also have jacks at the rear. i was considering adding others,our 30 lb cocker spaniel sets evrything in motion when he trots through to camper.


btw
my wife loves your dogs as she is a schnauzer person.

[JRTJH]

bob48,

If you look at any "18 wheeler flatbed trailer" you'll see that it has an "arched frame" when empty. The "arch" helps maintain a level deck once the trailer is loaded. That is also true with RV frames. As such, there will be two types of "bounce" (or spring) in your RV when it's parked. The first is "suspension bounce" and is very difficult to eliminate, although lifting the RV off its wheels is one way to remove that "bounce". The other, "chassis bounce" or "frame rail bounce" is much more difficult to eliminate. Even if you blocked your RV and used shims to "tighten everything up" as you walk on the floor, you'll still get some "bounce". It's pretty much inherent to the way RV frames are designed and can't be completely eliminated.

Probably the best you can expect is to add an additional set of "scissors jacks" to the center of your frame, probably just aft of (or just forward of) your axles. Tightening those to the ground would help remove much of the "suspension bounce" and help with "some but not all" of the "chassis bounce". Even then, after sitting and settling for a period of time, you're going to find that some of the bounce returns.