A topic for MYTH BUSTERS: Opening doors, hood, etc "to prevent damage when lifting?

[Paul Workman]

I first ran into this practice a couple years or so ago at a local Discount Tire store.

The short of it was that a corporate directive was at play, and the directive (according to the manager) required they open the hood, doors, etc before jacking or lifting the car. I was required to sign a waiver before they'd lift the car if I didn't allow them to open the panels. I signed it: of course the car didn't disintegrate before our very eyes as result

As a suggestion, and maybe an article for our Club's HOTB magazine, would there be anyone who'd like to research and get to the bottom of this "precautionary procedure"?

It might be fun!

.

[secondchance]

Doors on my 79 Trans Am would get wedged and wouldn’t open after the car being lifted.

[Ccmano]

Yes! Probably the #1 C4 myth.... I have lifted many C4’s without an issue. Can’t say I have ever even heard of a problem as a result of lifting. You would think it would be in the owners manual, FSM(not in my 90’ anyway) or in a TSB, I’m not aware of any.

The only thing I have seen is damage to the hood and doors when closing the hood with the doors open.
H

[Paul Workman]

Originally Posted by secondchance

Doors on my 79 Trans Am would get wedged and wouldn’t open after the car being lifted.

On two occations I accidently drove my 95 LT1 car over the end of a pair of wheel ramps. The car crashes down onto the ramps, landimg on the frame just behind the front tires. If somthing was going to "pop" I'd say those were the times when it might happen...BUT DIDN'T! (After the 2nd time I left those ramps on the curb. In an hour they were someone else's problem, and good riddance!

[efnfast]

I would think the car would be stronger and stiffer with all the doors and windows closed?????

[ghlkal]

Originally Posted by efnfast

I would think the car would be stronger and stiffer with all the doors and windows closed?????

Yeah. I've often heard to make sure the hood and doors were _closed_ before lifting.



I wonder if it really makes any difference.



Good idea, Paul, someone needs to investigate this and write it up.

[32valvesftw]

I thought one of the concerns is that is that some stress / flex in the frame may get transferred to the top and crack it. That said I have jacked mine up a number of times and always keep the doors and hatch closed with no ill effects.
I think the Engineering needed to PROVE this is quite complicated and would require a Finite Element Analysis and a bunch of 3D CAD work. However if some one has some strain gauges laying around, I'd be willing to experiment by putting some strain gauges on the frame and other places to see what kind of readings you get when jacking the car up both ways doors and hatch open as well as closed.

[efnfast]

Originally Posted by Paul Workman

On two occations I accidently drove my 95 LT1 car over the end of a pair of wheel ramps. The car crashes down onto the ramps, landimg on the frame just behind the front tires. If somthing was going to "pop" I'd say those were the times when it might happen...BUT DIDN'T! (After the 2nd time I left those ramps on the curb. In an hour they were someone else's problem, and good riddance!

Um, twice Paul?

[32valvZ]

Well, I just dismount my wheels/tires and bring them to the shop for new skins, then bring them home and mount them myself. That said, I never open the doors, hood or anything else.... Ive not had a problem with any of the 5 C4's I've owned.

[Tripler]

Been lifting the Z up on the Quick Jack with everything closed , then open and close everything with no issues that I can see . Only creaking I hear are the wheels sliding while lifting .
If you saw our driveway grade you would see the huge twist test our car gets when backing out . I have seen no issues with the car finish .
Would the owners manual have a say in this ?