Safe and proper use of stabilizer jacks

Safe and proper use of stabilizer jacks

By Russ and Tiña De Maris

RVs, being built light for easy (and economical) travel are not “rock solid” in camp. The longer they are, the more they tend to rock and shake as folks move about inside. To that end, most travel trailers and fifth wheels are equipped with stabilizer jacks.

On a fifth wheel, the “landing gear” acts as a stabilizer up front, but additional stabilizers are typically found at the rear. Travel trailer fans, if you unhitch from your tow vehicle and rest the trailer on the jack foot, you’ll certainly know the lack of stability. Many travel trailers have at least four stabilizer jacks, some have more.

too high jack
A jack too high — remove blocking

How can you safely and effectively use your stabilizer jacks? First, try and park on level ground as much as possible. That saves you from having to a lot of wheel blocking. Prior to unhitching either a 5er or travel trailer, chock your wheels to prevent any rolling.

Stabilizer jacks are just that: They’re for stability, and many jack manufacturers warn their product isn’t intended for leveling, so you’ll need to handle that leveling process before deploying the stabilizers. Hopefully you’ll have the jack manufacturer’s instruction manual available to you. If not, we provide some general guidelines.

First, on the subject of jack pads. It’s not a bad idea to slip a piece of wood between the bottom of the jack and the ground. It can protect asphalt from damage, and on mooshy ground, prevent the jack from digging into the terra not-so-firma. HOWEVER, there is a danger of using too much blocking.

Here’s a position we’ve had to repent on: Scissor style stabilizer jacks have their rated strength ONLY after being extended out so far. Here’s a quote from one jack manual: “This jack’s weight capacity is 5,000 lb. only between 13-3/4” and 23-1/2”; the weight capacity dras­tically reduces as the height drops below this level. Do not apply a load to this jack below 13-3/4” in height.”

I know in the past we’ve used “high level” blocks under our jacks, in part because there was less work involved–don’t have to run the jack out so far. But with this information in hand, we now use much less in the way of blocking. Yes, scissor jacks can get “wobbly” if extended w-a-y out. Therefore, a higher stack of blocking might be in order if you have a long way to crank out the jack.

5000 pound jack
A 5,000 pound rated jack — set for a good, stable lift

So crank out the scissor jack until you hit resistance. Then turn the crank another rotation or so and call it good. Don’t try to crank the trailer up, and NEVER use a stabilizer jack to raise your trailer for tire changing. If it “lets go” at the wrong time, serious damage to the jack (not to mention the jack’s owner) can occur.

We also have a few “stacker” jacks that we stash away in our storage area. These critters are portable units that use a screw type device for assisting with stabilizing. Here, place the head of the jack directly under the trailer frame, NOT under an axle. Crank the jack to the resistance point, and then add another turn or two.

photos: R & T De Maris