I've been reading posts about jacking the C-3. Now i have read do not open convertible doors when up on jack stands. That makes senses. I have also read to open doors ,unlatch t-tops , open hood on coupes when on jack stands. One would think leaving the car all closed up ,doors closed t-tops locked, hood down would make the car more rigid. As you shouldn't open the doors on a convertible. Am i missing something here?

 

Hi oc,
On my 71 coupe I jack with the doors closed, the windows up, and the roof panels in place.

Once the car is raised I open/close the doors and hood, and remove/replace the roof panels as needed.

I use the GM suggested locations to jack and place the (6) jack stands.
Regards,
Alan

 

Thanks,Allen some have said it puts stress on the fiber glass panels if you leave the doors closed t-tops locked, This just didn't make much sense to me.

 

Hi oc,
If the frame/birdcage is THAT flexible on a coupe, there's reason for concern!
Regards,
Alan

 

NO...you are thinking correctly....somewhat...because it depends.

When I jack up one that is on the floor and lifting the front clip or rear clip I do not do jack squat. The T-tops are left alone and secured and I do not open anything...it is not needed due to the dynamics at play. Or at least I have been super lucky for over 30+ years doing this stuff. NEVER one problem. Keep in mind I do not generally raise a Corvette from the side. If and when I do only raise one side....which is extremely rare that i do....and I mean extremely rare....I am watching it like a hawk. Most of the time I will drive the Corvette up on some low ramps I made and do both the front are rear wheels on that side.

When lifting one on a lift where you are lifting up on the frame in the suggested areas...that is when I carefully WATCH what is going on when I start to lift the car. If I am seeing movement MORE than what I like... I STOP. And change my plan on how it is going to be raised for whatever service work I need to do due to issues that the car has that raise my concerns. Many people man not have seen like I have that the front clip is really heavy when it is supported by GM recommended location for support. I have seen the gap at the top portion of the door above of the upper hinge to the top hood surround panel widen greatly....and that is due to all of the stress of the frame with the radiator, headlights and engine pulling down. And the fiberglass gusset bonding strip that is pop riveted and bonded to the birdcage/plenum gets fatigued when raised like GM recommends...the rivets can fail and WHAM...you now have problem....and water leaks can often times be one of them. And thinking that the rest of the fiberglass panels that create the cowl/plenum is going to hold up all that weight...all the time......guess again. I know that it will...because I also know that fatigue will eventually come into play. And if it doesn't...due to person never raised their Corvette...then count your blessings. I know it is not the same but the principle of fatigue is....so many commercial airplanes are retired and not used due to there is a limit on how many hours it can fly due to they know that it can fall apart in the sky due to....metal fatigue.

I have the safety support stands that I can put under the engine cradle and rear differential area to raise it up and close up the gaps when I get the car all the way up on the lift....but sometimes....the gaps increasing as much as I have seen them even makes me scared to get it up and get it safely supported.

The way I look at it...people bring their cars to me for repair and not to get damaged. If I have to do a repair that would obviously be easier up on a lift..and have to do it on the ground with the car supported correctly with jack stands...that is what I do.

DUB

 

 

Thanks, Dub
I will keep my doors t-tops closed. Avoid jacking one side only. Watch gaps as jacking the car up. Sounds like advice

 

I am only passing along the experiences that I have encountered. I can never assume that the next Corvette I get in is 'good to go'. So many I work on have had a hard life and have rust and numerous other issues...but are still daily drivers.

DUB