This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
I have 20 ton screw jack here that was my great grandpa's and he got it used. He couldn't afford new back in the Great Depression. It keeps getting passed down the generations. They used to use them for lifting the floor joists in the barn so they could put temporary support posts and beams in. As more hay was put into the hay loft the floor joists would sag. So they would jack them up and put more support posts and beams in. When enough hay was removed, the joists would lift off the top of the temporary posts and beams and they would fall over.
They are bloody simple mechanical things. The only thing that will kill them is rust in the screw threads from lack of lubrication and getting wet.
Most screw jacks use grease between the moving surfaces. Clean the old grease off the screw threads, and replace it with thin layer of any old grease. Usually you don't grease the pivot surface between top of the screw post and the plate that supports the load. It needs some friction to keep it from turning and lowering the load. That is all the maintenance most need. You could repaint it if you want. I haven't bothered. I just keep mine inside. If I have to leave it in a spot holding up a load where rain may get on it, I'll take some plastic cling wrap and wrap it around the exposed part of the screw post and top of the base. That keeps the water out of the critical screw jack mechanism. I use mine when changing tires on loaded silage wagons, the TMR, and tractors. My silage wagons can easily have over 20 tons of load in them. Most jacks can't handle that much. A fully loaded TMR is a lightweight at only 10 tons. For most other uses it is overkill.
