I think Lizbeth is talking about leveling scissors jacks
, or something similar attached to the frame
, while Bob and Judy are currently using the BAL Light Trailer Tire Leveler
, which lifts the tire
BAL also has the "single leg" style of device, such as the BAL Light Trailer Stabilizer Jack
, like the pair I put on my Boler
. There are higher-capacity versions from BAL and others.
I believe that in BAL's terms, a leveler
lifts one side or corner of the RV to level it, and supports it there, while a stabilizer
just provides rigid support to an RV which has already been leveled by some other means. In practice, a last bit of fine leveling can be done with stabilizers, but the stabilizers are not asked to extend while carrying a significant fraction of the RV's weight
If a leveling jack is used at any location other than very near the mounting points of the suspension on the frame
, then the load on the frame is shifted when the jack is raised. The consensus in earlier discussions in this forum is that most of our trailers' frames are not stiff enough for this, and bend under the shifting load. I assume that's why Lizbeth mentioned that their other trailer's frame "can take the load". That would presumably also be why Donna suggested that in changing from lifting the tire (and thus lifting the trailer by the suspension) to jacking on the frame, the jacking point should be very near the suspension mounts.
Due to this issue of where loads are placed on the frame, I mounted my stabilizer jacks on the frame behind the suspension, but as close to the spring mounts as practical. I drive one wheel up on blocks to level side-to-side, and crank the tongue jack (acting as a leveling jack) to adjust for front-to-back level. The rigid stabilizer jacks exist to keep the trailer from moving on its springs, and tweak the level slightly; whether or not any more stabilizers are needed would depend on the stiffness of the frame, and I think (after limited trial) that in my Boler
1700 I will be happy without additional stabilizers - the trailer has most of it's weight
on the tires
, just enough on the stabilizers just behind the axle
to stop bouncing, and the tongue jack on the front.
I am interested in mechanical designs to address the various challenges of RVs, so I usually notice interesting products, and I have not heard of a device to lift both tires of a tandem
, so that leaves the stack-of-blocks approach, or jacking on the frame instead of lifting the suspension (via the tires). I think jacking on the frame (Donna's suggestion) would be just as quick and easy as the tire leveler, if there is a good frame point for mounting with easy access for cranking (or pumping, or whatever). A power jack (scissors or other design) might solve access problems, but mounting is still an issue.