First off I love my Quickjack. I use it a lot and it is one of the best tools I ever bought. It lifts my C3, my C6 and my wife's Mini Cooper. But today I found something I hadn't noticed before and I want to share it with you. It has been under my C3 for the past few months. It usually is up in the air but depending on what I am doing, it goes up and down quite a bit. I always took notice that it hadn't slid too far under the car, and then maybe miss the frame. This morning I went out to jack up the car. When I got it in the air I did a quick visual to make sure it all looked good and I almost had one of those holy crap moments. The picture is dark but if you look at where the rubber block is, it is not under the frame. You can see that the jack is almost touching the rear wheel. When I started this project it was almost touching the front wheel. And The problem was that when it was UP the block was barely under the frame at the back, but when i started ti was a good 4-5 inches from the back end of the frame..
II have nice clean almost slick floors. It appears that all that up and down was making my Quickjack walk towards the back of the car. The car didn't slide while up on the jacks, and I know that the block was in a good place when I first started a few weeks ago. I figured out the issue and I am now more aware of this walking. If you are only lifting once or twice before you put them away, you won't have to worry about this. But if you are on a long term project, keep an eye out. Luckily I am always thinking about how these things can fail so I do that walk around each time I lift any car. I also put a piece of tape on the floor and a corresponding one on the jack. Then a simple hash mark will tell me if things had changed. I have to keep reminding myself that things move. Just wanted to pass this along. Thx.

 

Interesting….that lateral movement when it goes up and down likely imparts some horizontal force that can cause movement. Can you determine if the lift creep is at the floor or at the car frame or both?

Also what about if the car's suspension is exerting some creep each time it goes up and down?

 

I've got a set of wood spacers that fit into the jack wells and hold the block in the right spot. One way around for lifting the car forward and the other for lifting it towards the rear. I find it helps. I alight the jack at the rear where I know it should be to the rear tire and the second tread and then make sure it's parallel looking to the rocker and being excessively paranoid I always have a look at the blocks as soon as the jack basically comes in solid contact with the car and starts to take a bit of weight.

I know my car doesn't go down exactly where it was before it goes up, mostly due to the suspension geometry where the rear wheels are no sliding sideways back to where they would sit, that usually makes the quickjack let go of the rear before the front and the car moves ahead a little as a result
That said, my floor isn't nearly as nice and smooth as yours there

M

 

The movement is the jack on the floor. The car is almost exactly where I parked it. And an Automatic so it's not rolling around. But once the lift moves back, the blocks which have not moved ( I push them back and inside the corner sections as far as they can go so that they can't move) .
If the lift slides back say 1/4" ( that's extreme for one lift, just an example), the blocks hit the car frame 1/4" behind where the were originally set. Multiply that for as many tiems as you lift and lower, pretty soon it's a big deal. Mine has been up and down a lot lately as I do some interior stuff.
Mooser, you understand the Quickjack creep, yours moves forward I guess because of the direction your jacks are facing under the car. And I am paranoid about this stuff too. Which makes me even more upset that I didn't see this happening before. As said, it isn't a concern normally, but if you use it a lot, withought realigning it, you might be in for a surprise.

 

the car usually will move a little as the tires come down and they stick to a smooth surface like your floor it will tend to want to stay where it came down so it isnt in the same spot as it was lifted. As with any time you raise your car check it every time, your life will depend on it. On the bright side those rubber blocks are siped so they will grab your frame pretty good. THey will flex really well and still hold the frame.

 

I usually have a different issue. When lowering the car the jack doesn't move but car moves as it locks again when the manual trans. Usually 1/2" from usual position.

 

I've noticed the "creep" when I cycle the Quick Jack up / down. Does not take many cycles to move far enough to be concerned and have to reposition the jack or the lifting blocks. We're all in the same check - check - check the position of the lifting blocks in relationship to the car frame as the lift begins to raise the car. I also put two screw jacks under each side once the Quick Jack is locked into position....just to be extra safe.

I like your garage floor.

The painters tape is a great idea for easy positioning of the jack. Thanks for sharing. I like Mooser's wooden spacer idea too for the rubber blocks. Great forum - thanks for passing along ideas and tips.