A lesson in convertible body flex

Discussion in 'The ragtop shop' started by wildcatsrule, Aug 4, 2018.

  1. wildcatsrule

    wildcatsrule Well-Known Member

    I had a new experience today. I took my convertible to the tire shop to have some new tires put on. They raised the car by the frame rails just enough off the ground to work on the tires. I needed to get something out of the car, but when I tried to open the door, it wouldn't budge! Tried the passenger side door, same thing. As soon as the car was back on the ground, doors opened no problem. So convertible bodies definitely do flex!
     
  2. Briz

    Briz Platinum Level Contributor

    I was under the impression that the convertible had a stronger reinforced frame.
     
  3. JoeBlog

    JoeBlog Platinum Level Contributor

    I would I would think that with the roof up, there’d be minimal flex; these are boxed frames were talking about. I’ve had my roof down and could open and close both doors easily even with sitting passengers. I’m wondering exactly where the car was lifted; if too far front and rear, it might “squeeze” the doors closed. The corner points on the frame don’t exactly transfer stresses the way the suspension points do. I’d also be checking my frame to see if there were issues I was unaware of.
     
  4. Philip66

    Philip66 Well-Known Member

    I’ve had this happen to different convertibles over the years.
    It throws you back a little bit!
    But it is nothing to worry about in my opinion, it has to do with the lift points and the frame flex.
    All frames flex.
     
  5. dynaflow

    dynaflow shiftless...

    One of the joys of convertibles. I remember road testing new convertibles in '60s before clean-up crew removed all those little stickers on windshield, stickers moved back and forth about an inch.
    Imagine what it would do without a boxed frame...
     
  6. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    Rule #1, never open the doors on a convertible when it's on the lift
     
  7. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    These cars move and bend all over the place. Even the hard tops. You can watch the frame sag and the fender gaps change with jack stands behind the front wheels. They are not rigid.
     
  8. 69 GS 400

    69 GS 400 Well-Known Member

    Some flex is good. Seen a show on it along time ago. It is meant to absorb and spread out the force of impact. You would not want to be in a high speed collision impact vehicle with no flex.
     
  9. Briz

    Briz Platinum Level Contributor

    Wouldn't want to be in a high speed crash in any old car. You're gonna die.
     
  10. 69GS400s

    69GS400s ...my own amusement ride!

     
  11. My3Buicks

    My3Buicks Proud Liberal

    Never had that issue with the big Buick's, there is certainly body flex, but have had them jacked up in various positions and have always been able to open/close doors. It certainly isn't an issue with Reatta convertibles, have had three of them with no issue like that.
     
  12. Briz

    Briz Platinum Level Contributor

    Unibody
     
  13. My3Buicks

    My3Buicks Proud Liberal

     
  14. BQUICK

    BQUICK Well-Known Member

    I had a rollbar in my 71 years ago and it was night and day difference. Even handled better....
     
  15. sriley531

    sriley531 Big green hunk of $#*^....

    Yep. I had the green car on jackstands and opened the door. Now I have some chipped paint on the front edge of the door to fix .... :mad:
     
  16. 71purplebuick

    71purplebuick Well-Known Member

    I had the same experience on my 71...could never open the doors when it was on a lift or up on blocks. After changing out the body bushings a few years ago it made all the difference in the world for the body flex. Now I notice no difference between on the ground or up on the lift/jack stands. The factory rubber bushings just don't compare to a new set of poly, much less after almost 50 years!

    It was a big undertaking to change out the bushings but it was worth it. Had to cut access for the two rear bolts by the trunk and one in driver's side floor...worth it in the end.
     
  17. chucknixon

    chucknixon Founders Club Member

    Has happen to me with the 67 GS400 convertible several times in the past few months as we lifted the car to remove and re-install bumpers, shocks etc. I wish it had the 'X' frame that other cars have.
     
  18. Premier 350

    Premier 350 Chris (aka Webby)

    Many moons ago I had an Impala 4dr hardtop that someone cut down into a convertible. Doors rattled a little over railway crossings, otherwise OK. I did use the bumper jack on the rear once and watched the rear door-to-quarter gap close right up, then return to normal once it was on the ground. Wasn't game to open any door. On the same flex topic, a mate who owns a tyre store won't use a scissor lift under Ford Falcon pickups, if loaded. Too much flex. And here's a Hilux with 'some' issues. busted-ute-from-web.jpg
     
  19. Nailhead Ronnie

    Nailhead Ronnie Life's 2 Short. Live like it.

    X 100
     
  20. BUQUICK

    BUQUICK I'm your huckleberry.

    Have someone drive your A-body convertible with the top down while you ride as a passenger and reach out the window and put your finger in the gap between the door and the rear quarter panel just behind the outside door handle. As you move along the road you will feel the gap vary in width as the car flexes, especially if you go over an uneven surface like railroad tracks. I was a little shocked the first time I did this because I thought the convertible frame was really stiff. Well, it's not stiff enough to make up for not having a roof.
     

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