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

[Dynomite]

Originally Posted by 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 suspect the thought was that closed doors and closed hoods could be damaged trying to hold the frame in position when lifting on a corner.

BUT...….It is the windshield that is the issue (with the top on) and closed hoods and closed doors help the windshield from taking stress and cracking. The key is......never lift the ZR1 on a corner only...…...Lift from the Front center plate underneath or under the cross spring in the rear and then use jackstands. If you have to lift from the corner, only lift to get the wheel off the ground.

Some guys need instructions...…...I had a tire installation once with the guy placing a jack under the rocker panel cover (fiberglass) cracking the rocker panel just before I said NO

[DRM500RUBYZR-1]

Back in 93 I encountered a tire shop that insisted on opening the doors just enough to clear the jamb lock, before raising the car on the lift.
Their clear and stated concern was cracking the top.
I let them do it, but observed how the rest of the car "drooped" at each end as it left the ground, and how the space at the upper door area expanded, then closed up when returned to the ground.
After observing that, I never again, to this day, raise a C-4 with doors open.
The car is far more rigid with top on and doors closed than it is otherwise, at least empirically.
I also know the change in my cars behavior when the top is removed, which also confirms my decision to keep the car as rigid as possible when raising it off of the ground.
I am no engineer, but it is very easy to visually observe how the car reacts when the designed in rigidity is reduced.
The top, while expensive, is less important to me than stressing the entire car, although I have never had a c-4 top crack during lifting.
So, myth or fact, absent factual information to the contrary, I will keep all C-4's closed when lifting.
Marty

[dredgeguy]

Originally Posted by DRM500RUBYZR-1

Back in 93 I encountered a tire shop that insisted on opening the doors just enough to clear the jamb lock, before raising the car on the lift.
Their clear and stated concern was cracking the top.
I let them do it, but observed how the rest of the car "drooped" at each end as it left the ground, and how the space at the upper door area expanded, then closed up when returned to the ground.
After observing that, I never again, to this day, raise a C-4 with doors open.
The car is far more rigid with top on and doors closed than it is otherwise, at least empirically.
I also know the change in my cars behavior when the top is removed, which also confirms my decision to keep the car as rigid as possible when raising it off of the ground.
I am no engineer, but it is very easy to visually observe how the car reacts when the designed in rigidity is reduced.
The top, while expensive, is less important to me than stressing the entire car, although I have never had a c-4 top crack during lifting.
So, myth or fact, absent factual information to the contrary, I will keep all C-4's closed when lifting.
Marty

Hi Marty and greeting from lovely Dhaka, Bangladesh (yup I'm back here until the end of the month). Tell me that was not 246!

[Mystic ZR-1]

Charlie
I’ve said it before, you get to visit the places the rest of us can only dream about!

[FU]

Originally Posted by efnfast

Um, twice Paul?

Paul likes doing things twice

[Z51JEFF]

When I have the car on a jack the door will hit the striker in the jamb not quite right and the hood won’t line up to close so I’m always mindful of these issues when the car is on a jack.

[efnfast]

I tried to reinstall my roof one day while on unlevel surface. Wouldn't go, so they twist.
Anybody know GM's take on this? Owners manual? FSM?

[Paul Workman]

Originally Posted by efnfast

Um, twice Paul?

Yeah.... I enjoyed the heart-stopping panic that ensued so much that I had to try it one more time for the thrill of it!

Once: be careful next time...

Twice!??: F'k these pieces of crap!

I went to Harbor Freight and bought a pair of floor jacks and sturdy stands - like I saw Mark Haibeck using and never looked back! (Thinking now maybe a LIFT might be the way (especially for old bones) to go. BUT! I STILL AIN'T GONNA OPEN NO DOORS, HOOD, HATCH, TOP, ASHTRAY AND CONSOLE LID to prevent cracking something! (Sheesh...)

[DRM500RUBYZR-1]

Originally Posted by dredgeguy

Hi Marty and greeting from lovely Dhaka, Bangladesh (yup I'm back here until the end of the month). Tell me that was not 246!

uhmmmm, wellll,,,,,,,,,,,,,,uhhmmm,
OK
it wasn't our car...……………………….


Wait a minute, ahhhhhh………………………………. Charlie...………..


Yes, it was our car darn it!


After seeing that I never did it that way again.
That shop just did not want the liability of cracking the top.


BTW, we lifted a 78 Trans AM, and thought both front and back were going to break off from the middle so it's not only our C-4's that T Top car made ours look rigid.
Marty

[DRM500RUBYZR-1]

Originally Posted by efnfast

I tried to reinstall my roof one day while on unlevel surface. Wouldn't go, so they twist.
Anybody know GM's take on this? Owners manual? FSM?

The first time that happened to me on Ruby, I was shocked that no matter what sequence I tried, I could not get all four top bolts to start until I pulled the car back from the raised area below the one front tire.


And no, the 18,000 mile car never was in an accident as someone once theorized incorrectly.


I have always joked even on this forum how when I drive the car on the Boardwalk in Ocean City NJ for the annual show, if the top is off, I can actually see each corner moving in independent directions. it's subtle, but it is there.


So that top and the doors are integral to keeping the car rigid, or at least more so than it is if they are not all interlocked.


Marty