Trunk Deck Lift Failure

[rob the elder]

As you know I am in the process of doing considerable teardown and updates to Punisher. Among the high priority tasks is addressing the problem with the trunk lid opening mechanism. Like many of you, my trunk lid does not open well due to the lack of preload on the torsion bars. There have been various attempts made over the years to address this problem but I have not seen any that are a great long term solution.

I have used “booster” springs but they ended up bending the structural rod that runs transverse to the trunk in front of the hinges. And the springs wear out rather quickly. It’s just not a great solution.

I saw a post back in 2007? Where an owner pulled the rear bumper cover and installed spacers to increase the preload on the torsion bars in an attempt to get his trunk to open fully.

I am looking for your suggestions. I am pulling the bumper cover and am planning on de-installing the existing torsion bars and using a BFB to increase the preload. If anyone has any ideas on how to better accomplish this objective, I would very much like to learn them

[TomatoSoup]

Interesting, Rob. My trunk opens fine with the addition of just one spring (and no rod bending).

Have you ever replaced the torsion springs? Mebbe they just done wore out?

[rob the elder]

I have not. That is one thing I am going to find out.

I have a couple of spares . . . I know its a shocking surprise.

I am planning on swapping out the springs and seeing what the result is. Then I am planning on bending the current springs to increase the preload and see how difficult that process is and how effective the end result may be.

[ChopTop]

Ditto, used just one. However, I think the key is long-term & with no structural rod bending. Could a gas strut type system be used or modified to work in conjunction with the OEM set up? The only reason I used one spring was due to the rear bonnet barely popping up, and with two I was concerned the bonnet panel or brackets would/could possible start warping over time. Even with one spring it only pops up several inches. But that is more than enough to raise the rear bonnet the rest of the way manually.

[rob the elder]

I actually contacted a manufacturer of rear gate lifts and asked about the possibility of adapting an existing design to fit our needs but they basically said it was too hard.

I dont have any trouble getting the trunk to pop open, but it settles down to almost closed. I have to lift it up manually and then it falls back down again 90% of the time. It means that to put the top down, I have to pop the trunk, get into the car, release the top latch, then get out of the car, lift the trunk to get the kappa blanket out of the trunk, then while I am spreading the blanket over the top, the trunk falls to almost closed again. Then I have to lift the trunk lid while moving the top into the trunk. I then always have to align the blanket, while holding the trunk open with my sholder. Then I have to walk around to the other side of the trunk and adjust the blanket and press the top down against the stops. I have to hold the trunk open while manipulating the top and while walking around the car.

But worse is when at a show if I want to display with the trunk open I have to use a block of wood to hold it in the verticle position. Which is uncool.

[TomatoSoup]

Yeah, definitely sounds like sad springs.

By way of comparison, mine (with the one coil spring addition) opens to about 45deg. Still have to help it up to actually lift the roof out, but it will stay up for a while before slowly sagging back to ~45 deg again.

[ChopTop]

Sounds like a mechanical engineer might be able to come up with or fab an idea? I Google/Images and see a couple images where the gas strut is attached right to the trunk bracket, however because Kappa bonnets opens in reverse I'm not sure where it would be advisable to attach a gas strut.

Also, tried car hood prop but they all appear to be the same variation of a broom handle, makes me wonder is a static type OEM hood prop rod could be utilized?

[TIRESHREDDER]

How about this..............

Solstice Trunk Mod - 2 1/2 inch Spring - YouTube

[Carbon Sky]

I bought a few springs of various lengths for one that would work well. The first set I tried were not thick gauged enough, and the trunk lid eventually stretched out those springs.

The second set was just right. I have only 1 installed on the driver side.

Trunk Lid Spring Addition - YouTube

Trunk Lid Spring Addition - YouTube

I wrapped the bar with a small split piece of rubber tubing, then a little electrical tape just to make sure it wouldn't come off.



Seems to work ok for me. And as you can see, it definitely gets the lid up and holds it there. But perhaps that's because my additional spring is working in conjunction with a functioning tension rod system. Perhaps your tension rod system is damaged/worn, etc?

But sounds like you've found a professional solution to this problem. If you go that route, I'm sure there will be others interested in it.

[rob the elder]

Originally Posted by TIRESHREDDER How about this.............. Solstice Trunk Mod - 2 1/2 inch Spring - YouTube

Yes, I actually did that. If the springs are strong enough to lift the lid they will over time deform the rod. Mine was obviously deformed after six months. And I dont like that solution. I still have springs there and they do help but they look like shade tree engineering rather than a good solution.

Like my dad used to call a Cresent adjustable wrench an Oklahoma socket set.

[Carbon Sky]

Originally Posted by rob the elder Yes, I actually did that. If the springs are strong enough to lift the lid they will over time deform the rod. Mine was obviously deformed after six months. And I dont like that solution. I still have springs there and they do help but they look like shade tree engineering rather than a good solution. Like my dad used to call a Cresent adjustable wrench an Oklahoma socket set.

I wonder why yours was bending the rod? Was it maybe because the tension rod system has already failed so the additional springs were doing all the lifting, thus bending that rod? Or the springs you used were to short?

I've had mine for 3+ years now, and that rod is still entirely straight. I can take a picture to highlight it, but you can tell in the pic that rod isn't bent.

[MomsSol]

Since this is a family forum and young children may view content. The thread title has been changed.

Thank you.

[scottydel]

Originally Posted by rob the elder It means that to put the top down, I have to pop the trunk, get into the car, release the top latch, then get out of the car, lift the trunk to get the kappa blanket out of the trunk, then while I am spreading the blanket over the top, the trunk falls to almost closed again. Then I have to lift the trunk lid while moving the top into the trunk. I then always have to align the blanket, while holding the trunk open with my sholder. Then I have to walk around to the other side of the trunk and adjust the blanket and press the top down against the stops. I have to hold the trunk open while manipulating the top and while walking around the car.

Is the Kappa blanket a functional piece or just a blanket?

[TomatoSoup]

Originally Posted by MomsSol Since this is a family forum and young children may view content. The thread title has been changed. Thank you.

Really? If young children knew the double-entendre, then there would be no need to change the title anyway - it's too late. If they don't then it doesn't matter. Sometimes PC goes a bit far... just sayin'.

[juspimpin]

Originally Posted by rob the elder But worse is when at a show if I want to display with the trunk open I have to use a block of wood to hold it in the verticle position. Which is uncool.

I think you need a kickstand placed so as to not be seen during shows....