Jack Stands Placement

[jor]

I recall a thread awhile back regarding proper jacking points on our trucks. Someone, I think, said that it was harmful to use the twin I-Beams. I usually use either one to raise one side and the frame cross member to raise the whole front end. I use the axle housing or differential on the back. So my question is: Do others use the I-Beams and if not, why not? Thanks.

Here's a photo of the way I do it.
jor

[dcbullet]

I was one of the people who originally asked the question. Since then I've come across this instruction sticker for using the stock jack.



I would rather use the frame, however. Just seems more secure, I guess.

[Hawkrod]

The original jacking instructions were meant for lifting a single tire only. If you are lifting the whole front end then you should not use the I beams due to the risk of slippage caused by the I beam angle changing while lifting. Also once the vehicle is lifted the I beams should not be considered a safe jack stand location as any weight shift of the truck can also change the I beam angles and cause slippage and potential disaster. Hawkrod

[jor]

Thanks to you both. When I lift the whole front end I use jack stands on both I-beams and the leave the floor jack engaged with just a little bit of pressure if I can. If I need to work in that area I just have the jack stands. Now that I think about it I guess you are exactly right about the slippage so where is the best place to put the jack stands if not the I-beams?
jor

[boots]

I have used the i-beams before

[Hawkrod]

You can lift on an I beam but you should not support on one. As I already noted, it isn't safe. The strength of the beam is not the issue. The issue is the fact that the beam changes angles when load is applied to the vehicle. For example, if you are under the truck and unbolt and lower the trans the suspension will lift the truck slightly. Because the I beams are only moving on the outer end and pivoting on the inner end they travel in an arc. When weight is removed and the front end lifts it can be enough to allow the stand to tip. This is a Darwinian issue to be truthfull, some people need to learn physics from first hand experience while others are content to plod along listening to common sense and avoiding potentially dangerous situations that would otherwise not provide any benefit. As far as what any of you have done, it really has no bearing on safety, for example a lot of people have climbed under cars being held up by bumper jacks, in fact it still happens all the time, but unlike the lemmings, I am not inclined to do it just because somebody else does, Hawkrod

[flyboy2610]

I NEVER get under a vehicle supported by jack stands on a suspenion component. I place my stands on the frame rails, just behind the firewall.
And don't forget to give the truck a good shove to try ot knock it off the stands. If it won't come off the stands, it's safe.