A common problem associated with those lifting mechanisms Enrique, is the eventual failure of the shear pin that connects the drive mechanism to the whiffle tree. Of course there are multiple parts in the link, but the most common component to fail is that pin. In some cases it’s difficult to get to it. Here’s where you can download the manual for that lift mechanism. Use the manual to determine how to effectuate the repair. It shouldn’t be too difficult, but do your homework and read through the manual first. A closer inspection, once you open up everything, will determine your course of action. Wish I had more definitive solutions for you, but the manual should help.