Safe Jack Stand Placement
#31
Well congratulations, you've always done it completely W R O N G !!
(and yes, it is in fact a big deal)
In the future, please refrain from sharing misleading information like this with the intention of demonstrating that it is ok, because it most definitely is not!
Folks, this is a perfect pictorial example of what NOT to do.
#33
You know guys, from the looks of it, the takeapieandrun is quite possibly using extra heavy duty (3+ton) jack stands with an extra deep saddle. A close look shows that the saddle is actually deeper than the height of the pinch weld, so the pinch weld will not bear any load itself even when the stand is perpendicular to the seam, and again, the outer 'horns' will likely bear the weight, thereby denting/compressing into the unibody.
If I had to use THOSE stands, I think I would add some of the pads they make for just this purpose:
http://www.harborfreight.com/2-piece...and-95952.html
If I had to use THOSE stands, I think I would add some of the pads they make for just this purpose:
http://www.harborfreight.com/2-piece...and-95952.html
Last edited by vqsmile; 09-28-2014 at 02:23 PM.
#35
Nope, it never moves. The pinch weld is right up against the stands so there is nowhere for the car to move. Did coil install like this.
Btw, that's not my pic, I can't straddle the pinch welds with my stands because the center valley isn't deep enough.
Also, even if you have the stand straddling the pinch weld all of the weight goes on the portion behind the pinch weld; the part in front is just plastic. Which would be the same area bearing the load as the pic in my previous post demonstrates. In fact, since my jack stands are not deep enough to properly straddle the pinch weld, it would be more dangerous because they would be precariously balanced.
Btw, that's not my pic, I can't straddle the pinch welds with my stands because the center valley isn't deep enough.
Also, even if you have the stand straddling the pinch weld all of the weight goes on the portion behind the pinch weld; the part in front is just plastic. Which would be the same area bearing the load as the pic in my previous post demonstrates. In fact, since my jack stands are not deep enough to properly straddle the pinch weld, it would be more dangerous because they would be precariously balanced.
Last edited by takeapieandrun; 09-28-2014 at 02:43 AM.
#37
My car's been on stands for a good portion of this summer and I've always done it like this:
I just jack it up with my floor jack using a hockey puck to straddle the pinch weld, and then place the stand right next to it. It's not exactly on the recommended point but i only go up to 6 inches left or right with the placement, not a big deal.
I just jack it up with my floor jack using a hockey puck to straddle the pinch weld, and then place the stand right next to it. It's not exactly on the recommended point but i only go up to 6 inches left or right with the placement, not a big deal.
#38
...
I can't straddle the pinch welds with my stands because the center valley isn't deep enough.
Also, even if you have the stand straddling the pinch weld all of the weight goes on the portion behind the pinch weld; the part in front is just plastic. Which would be the same area bearing the load as the pic in my previous post demonstrates. In fact, since my jack stands are not deep enough to properly straddle the pinch weld, it would be more dangerous because they would be precariously balanced.
I can't straddle the pinch welds with my stands because the center valley isn't deep enough.
Also, even if you have the stand straddling the pinch weld all of the weight goes on the portion behind the pinch weld; the part in front is just plastic. Which would be the same area bearing the load as the pic in my previous post demonstrates. In fact, since my jack stands are not deep enough to properly straddle the pinch weld, it would be more dangerous because they would be precariously balanced.
Do you understand that you want your car to rest ON the pinch weld (or immediately adjacent to it, like right at the base of the vertical seam) so that it bears the weight properly? Having a shallower saddle in your jack stand than the one shown in the pic you posted is actually preferred. It is better to rest 100% on the pinch weld than it is to have the outer horns of the stand pressing into the unibody two or three inches away from the pinch weld, be it perpendicular or not! It may look sketchy having the weight of the car resting on that thin edge, but it is totally fine and will not slip off. You do need to treat it with some care though, as it will tend to bend if you get too frisky with it.
No, No, NO . . . that's totally W R O N G too!
People, for the record, you can't let the weight of the car bear on a simple sheet metal box. It can/will crush and weaken the car's unibody structure as a whole. The easiest way I can explain this is to consider the strength of your average empty coke can. If you stand it up on a flat surface, you can carefully step up onto it without crushing it. It is actually tremendously strong on the shear of it's cylindrical panel. However, if you first put even a small dent in the side of it before stepping up onto it, it will not be able to support your weight, as the shear panel has now been deformed causing a loss of uniformity of stress(weight) distribution. It essentially focuses the forces upon the dent and makes it collapse from there.
The unibody of your car function in much the same way. Since it is basically just a sheet metal can on its side, if you dent and/or cause deformities in the critical areas (like those boxed reinforcing beams under the car), you can pretty much count on your car losing some tangible portion of its engineered strength in a collision; not a good thing!
The following 2 users liked this post by vqsmile:
blnewt (09-28-2014),
Urbanengineer (09-28-2014)
#39
#42
Yes, but you certainly can also lift from the rear side body seam (shown as a "safety stand point" in the above diagram). If you use the jack that came with the car, then you HAVE to use the rear seam, but if you use a floor jack, then just go for the diff.
#45
Can some one please upload a set of photos for where to place the jack stands for the sedan?
I have the manual, but I would like to confirm with a set of real photos.
I have Rhino Ramps but the OEM front lip makes it too low.
I found one for the G37 Sedan, is this good?
https://www.myg37.com/forums/g37-sed...ml#post3993083
I have the manual, but I would like to confirm with a set of real photos.
I have Rhino Ramps but the OEM front lip makes it too low.
I found one for the G37 Sedan, is this good?
https://www.myg37.com/forums/g37-sed...ml#post3993083
Last edited by Samuel Kwok; 03-19-2018 at 07:31 PM.