68 GTO Hood Adjustment
 

What is the best way to lower the rear of the hood? When I close it the rear of the hood likes to stay about 1/8" above the fenders .. pushes right down by hand. Rear hinge to fender bolts are adjusted all the way down. I raised the front of the hinge in hopes it would kick the rear down some, results were inconclusive, I still have room to raise the front of the hinge farther up.

Hinges are not sloppy, and are well lubricated and move freely.

Also, it would be nice if I could shift the entire hood to the right slightly, about 1/16" .. it fits in the fenders square, but the gap on the right is a bit wider than the left. Are the hinges ever shimmed between the hinge and fender?

Thanks,

This is a common problem. I don't have the answer.
I had this same situation with my old hood for years. ('71 GTO)
Then one day the hood flew open while i was leaving my house, at maybe 25-30 MPH.
I pulled to the side, dreading what I might see.
I closed the hood and it was perfectly aligned, and the back was flush with the fenders. Miracle.
That hood had some rust and i eventually found a better hood.
I have the same right -to- left alignment that you've described with my new hood but the back is still flush.

There are a couple factors that causes this, others may have more info, so don't shoot the messenger.


Simple first. I had seen where some repop cowl seals are not correct (taller/thicker), and also made out of more dense foam. This prevents the hood from closing correctly in the rear. Over time, which is something that doesn't work with my OCD and patience, it does relax, almost enough to line up. Unsure entirely how long that might be, I never had waited, but did see some improvement in about a 2 year period.

Not so simple second. The hood bows from not properly closing the hood. It's imperative, the hinges are properly lubricated and adjusted, and you PUSH BACK THEN DOWN. By pushing on the forward lip of hood, while fully open, up (towards the sky), you can 'bow' it back.

Here's the rub. The more times you 'correct' it, the more the point of the leading edge of hinge, where it meets the hood, stresses, and, eventually it can crack. (ask me how I know)

This happens on many body styles, the longer the hood, the more susceptible.

Way I addressed the 'problem', is to weld an enforcement/brace running the length of the hinge, to the outer side of the hinge pad. I have done this with a number of cars, as have friends, using a piece of angle steel. If it's cleaned up properly, people rarely notice, unless they are looking for it.

Obviously, when adding the brace, you will have to repaint the hood, that's the kicker.


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First rule of major hood alignment in my shop is the latch is not installed. Once the hood and fenders fit, you bring the latch to the hood, not fight and build around where the latch wants the hood to go. If your latch is out and your hood sits to one side, there are a couple of ways to change that. You can try loosening one bolt (let's say the upper) to the hood on the side where the gap is wide, then move to the other side of the hood. Loosen the opposite (lower bolt) and put sideways pressure (shove) on the hood. While you have that pressure against the hood, tighten that lower bolt. If you have a helper, they can tighten the loose bolt on the other side. This method works awesome on trunk lids, occasionally on hoods. If this fails, loosen the fender bolts directly behind the hood hinges on both sides and have someone support the front of the hood. Then give it a firm but controlled sideways shove near the back, above the hinge area while a helper tightens those two bolts. Make sure the rear corner of your hood is well above fender height when fully opened so that you don't scar your fender top!

Like mentioned above, a stiff seal can cause the hood the stand up at the back. I take advantage of the hinge-to-fender bolt adjustments to overcome that. You said you have room for movement at the forward bolt, so no harm in trying that. Just be sure that the hinge to fender bolt does not have a washer! That will limit the amount of slot that you can use because the shoulder of the washer hits the inside edge of the hinge. The correct bolt is flanged and a smaller diameter.
Be aware that any time you rotate a hood hinge to bring a hood corner down, it moves the hood back on that side. Therefore, your hood is out of square with the opening and might hit the front corner of your fender on the side you rotate down. If rotating to raise the rear corner, it throws the opposite front corner closer to the fender. I’ve watched guys fixated on looking at the rear when lowering the hood, and not see it about to land on a fender at the front.

Another thing that some miss when building a front end is the need for shims at the upper cowl bolt. Shims are ugly, so some tend to leave them out when they can. Too few shims and the rear hood to fender corner gap may be tight, even though it fits the door perfectly. That can also make the back of the fender "dive". You have 3 bolts in that area, all are 3/8" with a 9/16" head. The upper (on top), the forward (behind the hinge pointing towards the firewall) and the upper jam bolt, hidden by the door. If you make sure the door jamb bolt stays tightened, loosen the other two that I mentioned and pry the fender upward, right in front of the upper bolt. Slip (another?) 1/8" shim in there and lower the hood to see if you’ve gained anything.
Way too much info, I know. I get carried away sometimes…:o

Sometimes moving the side of hood hinge opposite of the way you think it would go is the problem. For example, if I remember correctly, one thinks if the hinge rotates front of hinge down and back up would raise back of hood. It does the opposite. I had such problems with mine, I had to open slots in hinge more for more adjustment. Trial and error will be you best choice.

What I have seen some try in order to lower a rear corner is lower the hinge at both bolts. That does not work. What I described has worked for me for decades, as long as the hinge is not worn out. I guess I have been lucky.

OK, you guys have given me some ideas.

Cowl seal is original, hood has zero bow in it, hinges operate beautifully ( I also re swagged the rivets). Hood latch is not installed.

I do NOT have shims on the upper cowl/fender bolt .... something I immediately thought of .. but figured it would screw up my door gaps if I messed with that ... if I can leave the bolt behind the door tight then there is some hope adding a shim on the cowl.

Wind opening a hood would tend to pull the front hinge/fender bolt to the upper limit of the travel ... I still have some room to do that, so I'll try to move it the rest of the way before I try anything else.

400 ... some great ideas there. I see where you are coming from. Since the fender controls the position of the hinges, a shift in the geometry of the fender can subtly alter the angle of the hinges side to side. Loosening that bolt to cowl right behind the hinge would allow the part of the fender to which the hinge is bolted to flex and shift the side to side position of the top of the hinge. Jeez, how long did it take to figure that kind of thing out?

I absolutely think with these suggestions I can get the 1/8" I need in both the directions I need them.

I'll add my tip .... when a hood has fresh paint, and the fender to hood rubber spacers (the triangle ones) are squeaky clean .... grease the contact point between the spacers and the flange of the hood ... when I did that the hood settled much easier between the fenders.

Thanks guys

I didn't think the hinges were worn on my 70 gto ,,,,tried all the adjustments but couldn't get the hood to sit flush with the fender by the hinges. Could push down with my hand and it would stay there. I finally had them professionally rebuilt and now closes perfect every time. Also I got my hood to move a little sideways by loosening the bolts to the hood and pulling the hinge on one side and pushing on the other side. There's a little play in the hinge bolt hole to do this. Could move the whole hood maybe a 1/8th inch left or right.

Scott70 is correct about hinges causing problems. The set that came with my car were way off and no matter what I did, I couldn't get even close. I ordered a new set and it was way easier to get closer without a few mods on the holes.

I have new AMD hinges, same issue. I haven't had a chance to dial the hood in all the way yet, but I will get back to that car in like Oct.

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I just plan on pushing the back of the hood down after I close it. It's not like I'm doing it 100 times a day or anything.

I had mine rebuilt by willie at hoodhingerepair. very pleased.

Are the hood hinge springs used/new? I've solved at least two different hoods that sat up in the rear by replacing the springs.

Hinges are very nice used from a low mileage car ... but yeah, 50 year old springs could be an issue. The hood does go up and down very easily.

Are the repop springs good? Can they be installed on a hinge that is already on the vehicle?

I want to keep this in mind incase I can't solve the issue any other way.

But yes, in the big picture it's not a huge issue, all it takes to move it down is a slight pressure on the hood.

My gto only has 47000 miles and I believe the hinges are the originals. I've owned it since 86. The original springs were retained after the rebuild. When researching hinges after I couldn't get the hood to do what I wanted I found most people were saying you'd have better results with a quality rebuilt oem hinges than aftermarket.

Data, talk to Willie at Hood Hinge Repair.
https://www.hoodhingerepair.com/contact/

IIRC he advised me that the repop springs were for a Chevelle and didn't have the same coil count or strength as the 68-70 LeMans/GTO. In addition, the 71-72 GTO hoods were heavier and had stronger springs than the 68-70.

On his website, he says the only way to check for hinge wear is to remove the springs.

OG, I had these hinges on the bench with the springs removed, they seemed pretty tight. Oiled them up, worked them out and found a tad of side to side slop, but no elongated hole slop. So I put them in the hydraulic press and re-squeezed the rivets a bit, that snugged it right up. Then I oiled them good and gave them some more cycles (without springs) until they felt nice. Then reinstalled the springs and put the hood on.

There is no visible shifting at the pivot points (as might be seen with worn holes). I haven't tried very hard to get rid of the lift in the back yet ... posted here first to avoid wasting my time. Soon as I can get the wife to help I think some repositioning of the front of the hinge my solve my problem with the lift in back.