I was using my scissor jack to jack up my Taurus this weekend when it suddenly gave out - sending the car (with loosened lug nuts) swiftly to the ground!! Now, I wasn't going to get underneath the car until the jack stand was in place (it was waiting by the passenger door and actually scratched/dented the car slightly as it fell to the ground), but still - the sight of this collapse shook me up a bit. Looking at the scissor jack, there is this puny 1" long solid block-like piece that sits within the frame that the threaded screw passes through. It appears that the inner threads of this block just wore out, causing the threaded screw to slide right through it! Should've known something was up because the jack had gotten hard to turn at very low height (with no load). I had lubricated it a couple times with no real effect, but didn't think to investigate it any further.
Two things I've learned about scissor jacks:
1.) Use them only as an emergency device (changing a tire out on the road). They're not designed to be used as your primary lifting device. Even though I own a floor jack, I had gotten in the habit of using the scissor jack to lift my car for just about everything I did to my Taurus around the house. Why? It was just more convenient. Lugging out the floor jack is a pain in the ### for me. Also, I don't have the slotted adapter that fits on the face of the floor jack to lift up my cars. I used a double 2x4 this weekend, but I'll be getting the adapter (or making one) very soon because I won't be using the scissor jack anymore.
2.) If you notice your scissor jack getting very hard to turn, this is probably the first sign of failure. Look very closely at the threaded screw and what it passes through. Make sure there are no metal strands wrapped around the threaded screw - a sign of failing threads.
3.) Don't use just any scissor jack on any car. I always used only my Taurus jack with my Taurus, but occasionally I'd use my Colt scissor jack too. I noticed this weekend that the design of these two scissor jacks is quite different. The Colt jack, made for a lighter car, is probably even MORE prone to failure than the Taurus jack!!!
Well, I'm going to need to buy a replacement scissor jack now. Any suggestions? Is there such a thing as a WELL-DESIGNED scissor jack? It has to fit inside my donut spare within the driver's rear wheel well and be able to be screwed in place to hold the spare tire.
Probably will have to get the Ford replacement, right?