Electric stabilizers/levelers - information
My 2004 30' Classic Ltd. has Ultra 5000 electric stabilizers/levelers on it. Airstream did not provide any information on the amount of weight that these were designed to support. I wanted to know this, and also wanted to know if they were greased during the manufacturing process, since I was pretty sure the Airstream factory didn't grease them.
I contacted the manufacturer's customer service to find the answers. Some of you may be interested in the excellent answer I got as well, so here it is:
"The Power Twin has 2500 lift capacity on each leg, therefore the name Ultra 5000. It does have independent control, (a toggle switch for each motor, and a motor for each leg), so you should be able to level your coach. When people see 5000 lbs. of lift they expect to lift the trailer off the wheels. The jack may or may not have that ability. You could do a great deal of damage in doing so. (Via telephone, I was told not to lift any one corner of my trailer more than about 3" with the levelers. If more is needed, use blocks under the wheels.)
To level, lift the low side of your trailer with the jack legs. It will in effect roll the coach to a level position. (The low side rises to a level position, the high side will sag a bit) at this position, drop the legs on what was the high side, and plant them firmly in the ground. Your coach is now level & stable. (no shake) If the process had been preformed in the reverse order, one would need to lift the entire weight of the coach against the two legs that were first dropped. You have achieved your goal of leveling and stabilizing, with out a great amount of lift.
The issue of grease is no major concern. The motor gear assembly is packed in grease, the out put is only 30 to 40 RPM and will not turn for an extended period of time, so the grease will not get hot and run off or be damaged in any way. We did place a grease zerk on the motor assembly, you may want to give it a shot once each camping season, it has a bleeder,so you will see grease coming out when filled. The jack screw is made of steel and the drive nut is bronze, we use dissimilar metals to reduce friction, again low RPMs so no heat build up. This process tends to be self lubricating, if you choose you may want to use a light oil on the jack shaft, but no heavy grease, the grease tends to hold dirt and grit, where the oil will not.
The jack is a well proven and time tested. The only issues that you may encounter are a weak clutch or a broken shear pin. These are designed into the unit, they are made to brake or give way "BEFORE" other parts break, so that's a good thing.
I hope that I've answered your concerns, and good luck with your new unit and happy RVing.