How to (not where) place Jack stands?

[Alpinewhite]

Hi All

Inspired by you all great DIYers; I bought some craftsman tools and a 2 1/4 ton jack and jack stand stand set.

Today we tried to place my friends 99 323 in jack stands. We wanted to lift slowly and alternatively on the front sides.

I put the jack on the cross member and lifted it on one side till I could place a jack stand in completely low position. I removed the jack and made one one side rest on the jack stand placed. Placed jack on the cross member on the other side and lifted that side a little more than the prevoius side; all of a sudden the jack we already placed tilted outwards due to car's weight. If this has happened while one us were under the car :o.

What did I do wrong? Or the Jack stands are not good? It is craftsman 2 1/4 ton jack stands!

Jack stand spec: 2 14 tons; 17 inches max
Jack spec: 2 1/4 ton 15 inches max

Can place the jack on one side cross member and lift the car to the full 15 inches before even going to the other side? wont this put lots of shear to the car?

Thanks all of you
Arun

[liquidtiger720]

Do a search, this topic has been discussed quite a bit.

1.
http://www.nmia.com/%7Edgnrg/page_7.htm

2. http://www.bimmer.info/forum/showthread.php?t=1929&highlight=jack+position

3. http://www.r3vlimited.com/Tech/Jackpoints.jpg

[ArtemLepilov]

Hey - put the wheels of the car underneath the side railing. That makes it safer in case the car falls down, that way if you are under the car you will be relatively shaken but not stirred :)

-Artem

[Rob]

you will be relatively shaken but not stirred :)

-Artem

Lol, Artem, I dig that saying!

[joshua43214]

what did you do wrong? sorry, about every thing. In an effort to be more safe, you made things more dangerouse. start off thinking about how things roll and move when you lift them. The car or the jacks moves when you pump the jack, you MUST take this into account when you lift the car. lets create a picture in your mind. Pull the handbrake to lock the rear wheels,take a crane, hook it to the front bumper and lift. as the front bumper is raises, it pivots on the rear wheels. As the front bumper goes up, the point on the ground directly below the hook moves backwards, if you raise the bumper until its pointing straight up, it is now directly below the rear wheels.

"Oh" you say,"I am only raising it a bit at a time". doesnt matter. The angle of the jack relative to the car is important and you have to take it into account. If you place the jack under the engine support and raise the vehicle, either the jack must roll rearward or the car must roll forward. If you jack one side, place a stand under the car. the jack the other side, the jack must roll, or it will push the car off the other stand. use the picture above and raise the entire front end or rear end at once, watch stand placement, as the weight comes down on the stands, the relative movement of the pads will arc forward tiping the stand a bit, once it is on the stand, it should settle back if done properly. I normaly jack with the car in neutral and ebrake off, once the car is on the stands, then I place it in park with ebrake on. Lower the jack a bit so it is still under the support by about 1 inch. now, shake the car firmly, to make sure its safe, you can roll the car off the stands if its in neutral. If you are putting it on 4 stands, the jack MUST roll with the car, so make sure you are on a smooth surface and watch out for the wheels getting stuck on pebbles or holes in the pavement. If you are raising the rear end, block the front wheels after its on the stands.

[Alpinewhite]

Thanks Joshua for the theory, it makes lots of sense for me now.

Actually I should correct my question. I did not place the jack in the cross member but in the chasis rail. My bad I didn't know the difference until saw these links here

http://www.innerauto.com/Automotive_Systems/Underside_View/Chassis_Rail_DS/

and

http://www.innerauto.com/Automotive_Systems/Underside_View/Chassis_Rail_PS/

Let me rewrite what I did, correctly, so I give a good picture to you. Its scary to even think what if the car falls on me while I am under it.

This jack that I am having has wheels on all four sides. Now I know why they have it :)

Ok, this is what i did

1. Put the car in gear and parking.
2. Placed wheel chokes behind the rear wheels. Should I choke the front of the rear wheels too?
3. placed the jack under the chasis rail on the driver side. lifted this side up until I could place a jack stand in fully low position. My jack could lift 15 inches above; but i did lift only as much as it is needed to put a stand in fully low position. I put the jack stands under the driver door jack point.
4. I lowered the jack so that the driver side will rest on the jack stand. Placed the jack under the chasis rail of the passenger side. Lifted it little more than the other side then the driver side jack stand tiped off out wards.

According to your theory, it looks like my jack not only lifted the car but also pushed it side ways to the driver side. And probably on the driver side I didnt place the jack stand properly. Next time when I lift the car I will keep a watch on the jack and see if it moves behind a little bit while it is lifting the car, other wise it is going to push the car while it lifts it.

Thanks
Arun

[Alpinewhite]

Thats a great idea. I will buy some not so good used wheels from junk yard and put it under the front front wheel. Is that a good place to put it?

Thanks
Arun

[632 Regal]

i use the jack point to raise the side with 1 notch of the jack in the "hook" part so it wont slide off. I put the stands under the car on the other side of the rocker panel.

I know what im trying to say, just cant esplain it very good.

[laguner]

Buy a floor jack, if you don't have one. They're only 25-30 bucks.