Author Topic: '69 trunk lid hinge spring tension  (Read 2216 times)

Offline kansascarguy

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'69 trunk lid hinge spring tension
« on: May 04, 2015, 03:49:07 PM »
I'm finishing up a '70 GT-500 for my client and when he helped me set his trunk lid today, the springs wouldn't hold it up. And of course, they worked just swell before I tore the car down. We were wondering if Viagara or Cialis would help?

I can't remember whether or not I took the hinge springs off during the stripping/cleaning phase but I just got thru taking the hinge back off and removing the spring - counting the number of turns as it relaxed. It was one half-turn. That half-turn (times two hinges) really seems like it would be strong enough to do the job with the next alternative being a full turn. But I don't know if the spring can even be wound that far - or how far across the state I'll be flung if I can't hold on to it. And if it can go one full turn, will it bow the deck lid like the hoods tend to do? Does anybody know this valuable information and are willing to share? The correct number of turns of the coiled trunk hinge spring, that is?

If the answer is indeed one half-turn, then that begs the question as to why these once proud springs have sadly gone - flaccid. They were never blasted, dipped in acid, heated, or any other process that would drain tension from them. There only seems to be one way to increase the tension on these '69-'70 hinge springs and that's bending the stop tab. That tab looks like it might be bent forward about 1/8" tops - definitely not enough to make much difference.

Offline WT8095

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Re: '69 trunk lid hinge spring tension
« Reply #1 on: May 04, 2015, 04:34:23 PM »
I don't know how to ask this delicately - are you sure you're turning the springs so they are working together, not opposing each other?...  ;)
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline kansascarguy

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Re: '69 trunk lid hinge spring tension
« Reply #2 on: May 04, 2015, 05:15:33 PM »
Yes sir, they're both wound the right way - not cancelling each other out.

Offline midlife

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Re: '69 trunk lid hinge spring tension
« Reply #3 on: May 04, 2015, 10:26:19 PM »
On my 66, I found that there was adequate adjustment in the trunk lid mounting bolts to increase or release tension on the trunk lid.  Just a thought from out of the box...
Midlife Harness Restorations - http://midlifeharness.com

Offline WT8095

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Re: '69 trunk lid hinge spring tension
« Reply #4 on: May 05, 2015, 09:04:42 AM »
Yes sir, they're both wound the right way - not cancelling each other out.

Sorry, I had to ask  :)

I know you're working on a '70, and the hinges are different than '67-'68. But in the video below, the gentleman doing the demonstration mentions that if the torsion bars are swapped L/R, you would have to wind them a full turn. Sounds an awful lot like the situation you described.



I'm glad I have a fastback so I don't have to deal with those %$@#$#! springs!  ;)
Dave Z.

'68 fastback, S-code + C6. Special Paint (Rainbow promotion), DSO 710784. Actual build date 2/7/1968, San Jose.
'69 Cougar convertible, 351W-2V + FMX, Meadowlark Yellow.

Offline kansascarguy

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Re: '69 trunk lid hinge spring tension
« Reply #5 on: May 06, 2015, 01:15:14 PM »
FYI - I figured it out. The coiled trunk lid hinge springs on '69-'70 fastbacks require one full turn. I found an old hinge and immediately noticed the coils were much tighter than my "finished" part. I took it apart and found that indeed it was wound one full turn. But beware - trying to re-wind one of these is definitely not easy. If you can avoid taking the spring off, by all means avoid it. I made a special tool to do it but even then, I made sure to wear a facemask.