Body flex problem
Thread Starter
Racer
Joined: Sep 2005
Posts: 388
Likes: 1
From: Queretaro Qro
Body flex problem
I have a 70 vert and I used a mid rise lift to lift it this weekend. While the car was up, I tried to close the passenger door but it would not close. There were 1/4" gaps up top on both sides of the door and the door would not align with the door stop. Is this normal on convertibles? I did not have this problem with my 65 when I placed it on jack stands (supported on the four corners of the frame under the door). I am afraid to leave the car up for an extended period of time.
Should I be looking for the reason why the car is flexing that much?
Thanks,
Should I be looking for the reason why the car is flexing that much?
Thanks,
Melting Slicks
Joined: May 2006
Posts: 2,590
Likes: 403
From: Nashville TN
St. Jude Donor '09
I've wondered the same thing. I made the mistake one time and closed my hood while it was up on jack stands. When I took it off the stands, the hood was stuck and would not release. All I probably had to do was put the car back on stands, but that idea hadn't clicked in my head yet. Took me forever to get it to release through the firewall holes. Never doing that again. 
Le Mans Master
Joined: Jan 2007
Posts: 5,485
Likes: 7
From: Peekskill NY
ALL verts have a lot of body flex. I've owned 3 verts, a 66 Skylark, a 68 Skylark and a 69 Impala.
The first time I was in the rear seat in the 66 when a friend was driving and we went over some bumps I was shocked at the amount of misalignment in motion between the rear door edge and front edge of the quarter panel. I thought my frame was busted. There's no roof to solidify the body so you'll get the flex.
The first time I was in the rear seat in the 66 when a friend was driving and we went over some bumps I was shocked at the amount of misalignment in motion between the rear door edge and front edge of the quarter panel. I thought my frame was busted. There's no roof to solidify the body so you'll get the flex.
Instructor
Joined: Aug 2005
Posts: 234
Likes: 0
From: Covington, Virginia
The GM A-Bodies (chevelle/skylark/monte carlo/cutlass) all had xtra frame stuff welded on each side between the front wheels and the rear wheels. Even with all of that, with the top down, jack up one corner??? still enough flex to prevent the door from opening if closed....or closing if opened. Vettes did not have additional frame stiffy stuff.....go figure.
I had a 68 skylark and a 72 skylark convertible (wish I had the 72 back!!)
vert flex is not uncommon....
I had a 68 skylark and a 72 skylark convertible (wish I had the 72 back!!)
vert flex is not uncommon....
Race Director
Joined: Nov 1999
Posts: 10,643
Likes: 8
From: Foxfield CO 1970 Convertible
I have a 70 vert and I used a mid rise lift to lift it this weekend. While the car was up, I tried to close the passenger door but it would not close. There were 1/4" gaps up top on both sides of the door and the door would not align with the door stop. Is this normal on convertibles? I did not have this problem with my 65 when I placed it on jack stands (supported on the four corners of the frame under the door). I am afraid to leave the car up for an extended period of time.
Should I be looking for the reason why the car is flexing that much?
Thanks,
Should I be looking for the reason why the car is flexing that much?
Thanks,
Le Mans Master
Joined: Oct 2005
Posts: 9,429
Likes: 44
From: Macon, GA
My '68 sagged so badly on my mid rise lift that I ended up buying a 4-post lift. Best car related decision I have made to date without a doubt. 
Last edited by sperkins; Oct 10, 2007 at 11:32 PM.
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Burning Brakes
Joined: Oct 2002
Posts: 1,196
Likes: 47
From: Scarborough Maine Fredericksburg VA
I have the same issue with both t-top and vert. I was told by a local vet mech to always crack the doors when lifting the car. Not sure what it does but I always do it out of habit.
Sperkins - I have that same mid raise lift (Rotary?) Also just bought a new 4 post but will keep the mid as it is handy for brakes and detailing.
Sperkins - I have that same mid raise lift (Rotary?) Also just bought a new 4 post but will keep the mid as it is handy for brakes and detailing.
Le Mans Master
Joined: Oct 2005
Posts: 9,429
Likes: 44
From: Macon, GA
I was told by a local vet mech to always crack the doors when lifting the car. Not sure what it does but I always do it out of habit.
Sperkins - I have that same mid raise lift (Rotary?) Also just bought a new 4 post but will keep the mid as it is handy for brakes and detailing.
Sperkins - I have that same mid raise lift (Rotary?) Also just bought a new 4 post but will keep the mid as it is handy for brakes and detailing.
I also kept my mid rise lift for the same reasons, but I haven't used it since the 4-post arrived. I bought a sliding hydraulic jack that allows me to raise the wheels off the platform. I love it.
Burning Brakes
Joined: May 2004
Posts: 1,100
Likes: 3
From: belle plaine ks
I bought a two post lift for mine as I like to be able to do service work on brakes etc. My rule of thumb is not to leave car on lift for extended periods of time. The coupes are just as prone to problems as the vert. The frame is of lighter material than say your older cars from the fifties. Combine that with a fiberglass body that is probably only stressed to be sitting on the frame and you can have "problems". Jacking instructions for the car are specific and I aim my two poster arms for that area. If for some reason I had to support it for a while on the lift I would also put a freestanding tall jack stand under the front crossover.
I too experienced the problem of hood opening when I had the car on jack stands. After I let the car down though every thing went back to normal and I could then open the hood. Watch the front door to fender area gap as well.
I too experienced the problem of hood opening when I had the car on jack stands. After I let the car down though every thing went back to normal and I could then open the hood. Watch the front door to fender area gap as well.
Last edited by tigers123; Oct 11, 2007 at 12:32 PM.
Team Owner
Joined: Oct 2004
Posts: 23,831
Likes: 10
From: Springfield MO
St. Jude Donor '07
I think some of you guys have weak birdcages and/or frames. My 77 has never had any sagging problems - it's been on jackstands for a year and a half and the doors still operate perfectly.
Race Director
Joined: Apr 2007
Posts: 14,062
Likes: 602
From: Henderson Nv-Rohnert Park/Sonoma C o. ca/born in NY Rockaway Beach.
Well i just got my 77 back from the shop and the pass door is out of wack... He has always used a roll up lift, but maybe he didnt this time?
can see a big diffference in the door.
can see a big diffference in the door.
Safety Car
Joined: Jun 2005
Posts: 3,775
Likes: 4
my 69 vert has almost no body flex at all, and it has a rotted out frame.
i can jack it up any way i please, LF and RR, RR and FR, FL and FR, so and so forth, and leave it that way for months at a time. in fact, this year when i replaced my fuel lines i had it jacked up on the FR and RR for well over 2 months. i then jacked up the other side, while leaving this side up, to do some transmission work. my left rear tire was dangling in mid air when i jacked the front up, before i put a ramp under it.
all this time, the doors open and close fine, hood opens and closes fine, no cracks, no nothing. i even did a bunch of work inside the car like this and i was crawling all over inside of the car. even took off the hard top quite a few times.
the worst i saw in body flex was maybe a 1/4 inch movement in my deck lid.
i can jack it up any way i please, LF and RR, RR and FR, FL and FR, so and so forth, and leave it that way for months at a time. in fact, this year when i replaced my fuel lines i had it jacked up on the FR and RR for well over 2 months. i then jacked up the other side, while leaving this side up, to do some transmission work. my left rear tire was dangling in mid air when i jacked the front up, before i put a ramp under it.
all this time, the doors open and close fine, hood opens and closes fine, no cracks, no nothing. i even did a bunch of work inside the car like this and i was crawling all over inside of the car. even took off the hard top quite a few times.
the worst i saw in body flex was maybe a 1/4 inch movement in my deck lid.
Advanced
Joined: Jan 2006
Posts: 70
Likes: 1
From: Montreal
I jack mine up quite often and never open doors or unlock t-tops. No movement whatsoever. As a matter of fact, if I jack her up too high, I can almost take 3 wheels off the ground.
