Gas Flap Hood Corners Too High

[81dmc]

For years my car's hood has never sit like it should at the corners. I've tried different hood seals and positions, etc.

Is this a hood issue, or is it simply a body tub shape issue? I'm VIN 831 with a textured body...




If it's a hood issue, is there a way to reshape it without damaging?

If it's a body tub issue, where should I sand?

[Timeless]

https://dmctalk.org/showthread.php?16133-Fastening-the-hood-down/page2&highlight=HOOD+SEAL

[81dmc]

https://dmctalk.org/showthread.php?16133-Fastening-the-hood-down/page2&highlight=HOOD+SEAL
As I said in first post, seal is fine and I've tried every adjustment possible.

[poidog]

Your hood latch probably needs to be lowered.

https://dmctalk.org/showthread.php?16690-Hood-latch-adjustment

[81dmc]

Your hood latch probably needs to be lowered.

https://dmctalk.org/showthread.php?16690-Hood-latch-adjustment

First thing I ever did on the car. Didn?t help.

[poidog]

First thing I ever did on the car. Didn?t help.

I'm assuming then you tried adjusting your bumper stops too?

[David T]

First thing I ever did on the car. Didn?t help.

On most cars you have to enlarge the holes of the latch so you can get more adjustment and move the latch lower. Lots to do there. Increase the spring tension inside the latch (shorten the small spring) so the hood "pops" up so you don't need 2 hands to open the hood. Get a back-up cable installed so if the main cable doesn't work, you can still get the hood open. Adjust so the rear corners are just slightly low. Use the bump stops to bring the corners back up level with the fenders (keeps the corners from shaking while you drive). Make sure the bump stops are aligned so they will get captured in case of a front end collision so the hood doesn't decapitate the occupants. Lubricate the hinges, I have seen them completely rust out. Inspect the cable right at the release handle, the cable gets bent every time you use the handle and eventually the cable breaks right there. If you see it fraying get it replaced. Make sure the loop on the hood lines up and goes smoothly into the center of the latch. On some cars it rubs hard on the side of the latch and I have seen the hoops almost worn through. Lubricate the latch.

[81dmc]

On most cars you have to enlarge the holes of the latch so you can get more adjustment and move the latch lower. Lots to do there. Increase the spring tension inside the latch (shorten the small spring) so the hood "pops" up so you don't need 2 hands to open the hood. Get a back-up cable installed so if the main cable doesn't work, you can still get the hood open. Adjust so the rear corners are just slightly low. Use the bump stops to bring the corners back up level with the fenders (keeps the corners from shaking while you drive). Make sure the bump stops are aligned so they will get captured in case of a front end collision so the hood doesn't decapitate the occupants. Lubricate the hinges, I have seen them completely rust out. Inspect the cable right at the release handle, the cable gets bent every time you use the handle and eventually the cable breaks right there. If you see it fraying get it replaced. Make sure the loop on the hood lines up and goes smoothly into the center of the latch. On some cars it rubs hard on the side of the latch and I have seen the hoops almost worn through. Lubricate the latch.

Um.

If I pull the latch down anymore the hood won't close. The center is tight again the body, but the corners are not. Trying to figure out if there a way to bend hood back not shape, or if it?s better to sand the lip of the body tub near the latch so it closes further.

[Bitsyncmaster]

Um.

If I pull the latch down anymore the hood won't close. The center is tight again the body, but the corners are not. Trying to figure out if there a way to bend hood back not shape, or if it?s better to sand the lip of the body tub near the latch so it closes further.

I have the same problem. My edges are not pushing on the stops but the center is very tight.

[David T]

I have the same problem. My edges are not pushing on the stops but the center is very tight.

The fitment on the early cars was not as good as the later cars. Don't try bending the hood. Maybe sanding the fiberglass tub so the hood can close more is the way to go. The other possibility is to raise the fenders with some washers a little to meet the corners of the hood. But then the fenders may not line up well with the doors. Getting things to line up is all about compromises. Sometimes you must be satisfied with "good enough". Or maybe a thinner hood seal?

[81dmc]

I'm eventually going to try the sanding body tub thing. I have maybe an inch worth of washers stacked on front fenders.


Oh the joys of having one of the first 500 cars..

[Michael]

Moving the latch down will make the problem worse. Watch this video I made a few years ago starting at 3:50
It explains my thoughts and fixes.
Shimming fenders and moving the catch is old guard Jerry rig fixes. People just blindly followed and accepted it when you only needed to use a little common sense.


https://www.youtube.com/watch?v=t1L0AH1kjaU

PS: If you watch the whole video, I mispoke about the heat gun temps on correcting the fascia temps...I meant the heat gun got 1,500 degrees, not make the fascias that hot.

[81dmc]

Moving the latch down will make the problem worse. Watch this video I made a few years ago starting at 3:50
It explains my thoughts and fixes.
Shimming fenders and moving the catch is old guard Jerry rig fixes. People just blindly followed and accepted it when you only needed to use a little common sense.


https://www.youtube.com/watch?v=t1L0AH1kjaU

PS: If you watch the whole video, I mispoke about the heat gun temps on correcting the fascia temps...I meant the heat gun got 1,500 degrees, not make the fascias that hot.
Yeah the factory seal is a POS. I got rid of that awhile ago.

You say picking the hood up at the corner doesn't do it, but it does for gas flap cars. The whole thing flexes like a wet noodle because there's less meat reinforcing it at that corner.

Now I do agree on your lowering latch theory, because that made my hood worse over the years. IMO, the real fix would be dual hood latches at corners, but I don't feel like redesigning that part of the car right now lol.


In any case, the issue is much more pronounced on my early vin, and I attribute that to the body tub and gas flap hood imperfections. I?m going to experiment sometime this year and report back.

[Bitsyncmaster]

My problem is the fenders are also up to high because the door is to low. I moved my door front latch all the way up that it can go but still the front fenders need to go lower to line up with the doors.

[81dmc]

When I was talking about hood warpage, I'm referring to how ALEXAKOS fixed the hood shape. https://dmctalk.org/showthread.php?7014-Hood-panel-alignment

Kind of extreme.

[Bitsyncmaster]

Mine is just a little high on the drivers side. I used a sheet of paper to test where and how much the seal hits and it seems the seal is the problem. It locks the paper tight when closed and all other locations I can still pull the paper out. Problem seems to be at the curved area surrounding the gas fill area.

[mhanch]

(still better panel gaps than a Tesla)

[Bitsyncmaster]

What is the purpose of these. They do not hit the hood bumps.

[81dmc]

What is the purpose of these. They do not hit the hood bumps.
Those are what Dave T was referring to. Those catch the bump stops and prevent the hood from decapitating you in the event of a front end collision.

[Bitsyncmaster]

Those are what Dave T was referring to. Those catch the bump stops and prevent the hood from decapitating you in the event of a front end collision.

That makes sense. But I would not think those bump stops could stop much force.

[Rich]

That makes sense. But I would not think those bump stops could stop much force.

The 8mm threaded shafts of the stops should each withstand north of 2,000lb of shear force.

And the hood, being quite flat and relatively unreinforced, will buckle readily when crushed in a fore-aft direction.

The goal of the stops and the v-shaped capture brackets on each rear corner of the hood, is primarily to initiate an upward buckling failure in a front impact, making the still-hinged hood to move upward away from the windshield. The stops can withstand enough force to bend/buckle the sides of the hood and then break away - or bend over and release the capture brackets - as the bent hood goes up. The weaker hood latch alone probably can't do that.

You might have seen this DMC-12 front crash test movie. (https://www.youtube.com/watch?v=z524AipITiM) Look closely at the linked video, especially at the slo-mo replay at 3m:00s, to see the hood crumple and then fly up and away from the car while still on its hinges leaving the windshield cracked yet intact.

This particular test included prototype driver-passenger airbags. These had no effect on the management of the hood from what I can see.

[David T]

The 8mm threaded shafts of the stops should each withstand north of 2,000lb of shear force.

And the hood, being quite flat and relatively unreinforced, will buckle readily when crushed in a fore-aft direction.

The goal of the stops and the v-shaped capture brackets on each rear corner of the hood, is primarily to initiate an upward buckling failure in a front impact, making the still-hinged hood to move upward away from the windshield. The stops can withstand enough force to bend/buckle the sides of the hood and then break away - or bend over and release the capture brackets - as the bent hood goes up. The weaker hood latch alone probably can't do that.

You might have seen this DMC-12 front crash test movie. (https://www.youtube.com/watch?v=z524AipITiM) Look closely at the linked video, especially at the slo-mo replay at 3m:00s, to see the hood crumple and then fly up and away from the car while still on its hinges leaving the windshield cracked yet intact.

This particular test included prototype driver-passenger airbags. These had no effect on the management of the hood from what I can see.

The bump stops also (when properly adjusted) keep the corners of the hood from shaking and when the hood is closed keep the hood from being deflected if you put any weight on it. On most Deloreans none of them are adjusted right. If you adjust the latch you have to re-adjust the bump stops. I make the latch on the tight side (low) with the corners just a touch low so I then use the bump stops to hold the corners level with the fenders. Even with the best adjustment you never get both corners the same unless you use the bump stops to level them.

[GS450-Junkie]

Moving the latch down will make the problem worse. Watch this video I made a few years ago starting at 3:50
It explains my thoughts and fixes.
Shimming fenders and moving the catch is old guard Jerry rig fixes. People just blindly followed and accepted it when you only needed to use a little common sense.


https://www.youtube.com/watch?v=t1L0AH1kjaU

PS: If you watch the whole video, I mispoke about the heat gun temps on correcting the fascia temps...I meant the heat gun got 1,500 degrees, not make the fascias that hot.

I'd like to try a new seal as you mentioned. I don't have a Lowe's near me so I would have to order it. Do you have a direct link?

[Timeless]

Not Lowe's but Amazon carries it:

https://www.amazon.com/dp/B000I1QHA8/?coliid=I1Z5NC0CTFMGD&colid=209TTRLVTHPVN&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

[Michael]

Not Lowe's but Amazon carries it:

https://www.amazon.com/dp/B000I1QHA8/?coliid=I1Z5NC0CTFMGD&colid=209TTRLVTHPVN&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

That's it. Get two packs.

[Patrick C]

Not Lowe's but Amazon carries it:

https://www.amazon.com/dp/B000I1QHA8/?coliid=I1Z5NC0CTFMGD&colid=209TTRLVTHPVN&psc=1&ref_=list_c_wl_lv_ov_lig_dp_it

Or get it here in longer length so you don?t have 2 seams: https://www.mcmaster.com/product/93085K19

[dmcman73]

I know that this is an old thread, but just seeing this now since it got pushed up again.

My car has an early 500 hood and I have the issue with the corners sticking up past the fenders. The early 500 hoods had holes drilled out in the lower X that were later capped with the same rubber plugs used for the clutch master cylinder, I'm not sure why they have these large holes drilled into the lower part of the X frame.

Now, from what I've been told by Chris N and Rob, the early 500 hoods were not made well and had fitment issues and one of the issues was it sitting high even without a hood seal and slotting the latch to bring it down further. The only thing I found to "correct" this is to shim the fenders (starting from the corners at the windshield) upwards to meet the hood once you are able to get the hood as low as possible with the latch slotting and gaskets.

It doesn't look out of place and the edges of the doors do line up well with the fender. If there is a more "official" fix for this (besides getting a newer hood), I haven't found or heard of one.