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Hood and trunk alignment tip, for you pros too!

37K views 55 replies 13 participants last post by  tech69 
#1 ·
This is an old trick I learned many years ago from one of my mentors. I take it for granted as being a pretty basic move in aligning panels but again today I was working with an experienced pro who had no idea what I was talking about when I said to “Shim the hood down”. He responded “Shim it DOWN, what are you talking about?” I have had MANY techs do the same thing when I say to "shim it down". Again, this is basic stuff but I guess because it is kind of abstract and you have to look at how the hinge works and then it is clear, but until then “Shim it DOWN?” is what you think.

You can see by photo #1 that this hood is up a little. Number 2 shows where you would put this shim, and #3 and 4 show how the hood is down quite a bit with this shim being installed.

This is of course the same way you can lower the trunk lid on most all cars made for decades. Those ones with the non adjusting pivot at the front like a 68 Camaro, just shim down that hinge at the bolt closest to the rear of the car and the lid will come down.

Brian







 
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#4 ·
I put a really thick shim so that it would drastically lower the hood. If I wanted to align it properly it would have been thinner. You can use a washer too, that way it wouldn't look so funky. :mwink:

Brian
 
#6 ·
Yes, it's an eighth inch shim. A 1/16" would have been much closer to correct. I even have thinner ones used in wheel alignment that go down to a 64th inch.

Here is an alignment shim kit which is pretty handy. But they have the little handle on the top which makes them kinda funky to use on fenders and such.

Click here

Here are body shims.

Click here

I have some round ones like this as well, these don't look so much like a shim.

Click here
 
#7 ·
Now that is a great illustration on how to do that, using the hinge as it is currently on the car to align the panel up or down. At first it seemed counter-intuitive and then made sense when I studied the picture. I'd rather try this than fool around with moving the location of the hinge, hoping that didn't mess up the alignment somewhere else.
 
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#40 · (Edited)
before you get out shims and start rotating anything try to use lubricant spray and spray all the joints on your hinges and work it up and down for a couple of minutes. This is the most common problem with old hinges..

I didn't want to say it before but it could have been also Brian's problem with his freshly powder coated hinges. That's like a guaranteed problem after powder coating hinges. They always seem VERY stiff and as a result they won't lay down all the way.
 
#11 ·
I am thinking you are right, the hinges are mounted at a different angle now and are tilted farther forward then they were originally. If this is the case shimming between the hood and hinge will lower the hood but we are just guessing at exactly what will happen. Go for it and give it a try. You could also modify where it is mounted by pushing the metal in at the top mount so the hinge rotates back as it originally was.

Brian
 
#12 ·
I had a good time up there once on vacation (drove on up to BC) but I have 21 other states to go see before I start going to ones I have already been to, sorry. :D

Brian
 
#13 ·
lowering hood

wow at first i didnt get it...how could raising the hood where it needs to be lower work?...then it hit me...that shim is moving the front of the hood up..away from the locked in position.....therefor making the hood go down farther before it is in place...if it goes down farther so does the rear.. :cool:
 
#14 ·
This is how to look at it, the shim is moving the hinge further down, it is allowing the hinge to "close" more, thus lowering the hood. But it is affecting ONLY the back of the hood, it isn't doing a thing to the front. Lowing the front is ALL about lowing the latch and hood bumpers at the corners.

Brian
 
#15 ·
MARTINSR said:
YES that would raise the hood.

But hold on here, what kind of car are you talking about? If it's an older car you don't need to do this, you need to "rotate" the hinge back to lower the hood. This lowers it MUCH, MUCH more than simply pushing the hinges down.

Brian
This is completely backwards from the way you would think it should be done. No wonder we all struggle with it. Thanks for the insight!
 
#17 ·
MARTINSR said:
I put a really thick shim so that it would drastically lower the hood. If I wanted to align it properly it would have been thinner. You can use a washer too, that way it wouldn't look so funky. :mwink:

Brian
Your absolutly right shims do look funky.but the true pros would bend the hinge or the mounting surface to bring it up...If I wanted to lower that corner I would simply push the hood open a little farther than it wants to go.(bending both just a little)...OR if the corner is to low I would stick a piece of wood between the hinge and CLOSE the hood a little more than it wants to go .....works every time....kinda like fixing a sprung door.....when I see shims I see inexperianced help doing cobbled up repairs,especially in a car that shouldnt have ANY ,repaired or not....I guess back when shims were used at the factory to get panels to fit,they were exceptable to most but not now days.Sorry Brian I just cant go along with this one its like someone showing off a duplicolor paint job and recomending everyone use it..... :(
 
#18 ·
deadbodyman said:
Your absolutly right shims do look funky.but the true pros would bend the hinge or the mounting surface to bring it up...If I wanted to lower that corner I would simply push the hood open a little farther than it wants to go.(bending both just a little)...OR if the corner is to low I would stick a piece of wood between the hinge and CLOSE the hood a little more than it wants to go .....works every time....kinda like fixing a sprung door.....when I see shims I see inexperianced help doing cobbled up repairs,especially in a car that shouldnt have ANY ,repaired or not....I guess back when shims were used at the factory to get panels to fit,they were exceptable to most but not now days.Sorry Brian I just cant go along with this one its like someone showing off a duplicolor paint job and recomending everyone use it..... :(
We are all entitled to our opinion. The thing is, if someone doesn't understand how this could be done, could they understand how to bend the hinge? Also, we are talking about a concept where you can quickly adjust something without any damage, without any steep learning curve, with just a quick check one can see if the panel is going to be aligned at all.

And for someone who isn't as talented as you who could be reading this, the shim is a quick fix that most anyone is capible of doing.

I certainly see your point in that making it work by correcting the problem is the "best" way to go, while putting a shim there is the "bestest".

There are PILES of shims on a sixties GM car, do you eliminate all of them when restoring a car? No, unless you are making some mind blowing show car you would be using stacks of them on the front fenders for instance. What is one more on the trunk hinge to make a perfect fit? I don't know, I just don't see that big of a deal but also see your point and agree that you could eliminate them by bending the hinge.

Brian
 
#19 ·
Man did you get me thinking about this, "Real pros" don't do this. Wow that was a zinger to push me off the plate. LOL I walked away going holy crap I'm a "real pro" why would I be doing this? Then I got to thinking about WHEN I will do it and when will I recommend it, it's simple, I do it or recommend it when it is TOO LATE to bend the hinge! If you are assembling a new hood that has been painted and you are working on a late model car where you try to bend something and it folds the hood in half, you shim it instead.

I put one on the trunk lid of my Gran Sport, why, because it was all painted and new rubber in and I wanted to bring the back down a little without damaging the body and paint that I had FINALLY gotten done.

Geeeez now I can get back to work. :D

Brian
 
#20 ·
Here is an example, this is the trunk on my Gran Sport. It was all painted, and aligned,but with the new rubber it didn't fit as well and was sticking up a bit. I put a 1/32" shim (used in wheel alignments) painted red so it doesn't sand out much and made the lid fit perfect, I mean PERFECT, it is literally not the thickness of the paint off, it is flawless in height.

The car is FULL of shims, there were piles of shims on these cars, what's one more 1/32 one? :mwink:

Just how I see it. :D

Brian
 

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#21 ·
LOL brian, adjusting panels after thier painted can be quite frustrating thats true too.....Just to show you what can be done by bending ,if you look at the pic next to my avitar you'll notice the hinges on my 48...their out of an 02 Grand Am .....No they didnt fit at all ,not even close but I didnt have a pair of 48 hinges soooooooo,out came the torches ,these required a little more than some slight tweeking,but a little here and a little there then a little more and wallaaa there you go....OH ,and no shims.. :confused:
 
#22 ·
Shimming of all body panels and even bodies has been going on since the first car was hand built. (same can be said for home building). Ever time I disassemble a vehicle, I collect all the shims right along with nuts, bolts and special fasteners, for future use. When I retired and started building/restoring vehicles with my Bud, door, hood and panel alignment intrigued me a bit. My Bud, a retired master tool and die maker, had a great eye for determining what had to be done to make those perfect lines and at first, I always thought he was going in the wrong direction, but I soon learned that he was always right. Hard to learn that up is down and left is right!!

Trees
 
#23 ·
deadbodyman said:
LOL brian, adjusting panels after thier painted can be quite frustrating thats true too.....Just to show you what can be done by bending ,if you look at the pic next to my avitar you'll notice the hinges on my 48...their out of an 02 Grand Am .....No they didnt fit at all ,not even close but I didnt have a pair of 48 hinges soooooooo,out came the torches ,these required a little more than some slight tweeking,but a little here and a little there then a little more and wallaaa there you go....OH ,and no shims.. :confused:
I'm wondering, if when you get that car all painted and assemble with the rubber and find the lid high, are you going to remove the hinges and heat them, bend them and repaint them and re-install?

Brian
 
#25 ·
Shimming down is an option but in good restoration shops shimming on hoods and decklids is a no-no. If it appears it needs one there's usually always a way to fix it without resorting to shims. I can't remember the last time I put a shim in a hood/decklid. But for DIY'ers I can see the importance of shimming down.
 
#26 ·
There are restoration shops who wouldn't dream of using plastic filler too. :rolleyes: You are right though, the shim should be a last resort. I know I bend hinges to correct it too, however when a mistake has been made and the car is painted and done, a shim properly placed just isn't that big of a deal. As I have said, the car has STACKS of shims to make fenders fit at the factory, STACKS I have seen a half inch of shims on original cars. So a neatly placed shim to make your hood or trunk fit perfect just isn't a big deal. When I put my hood back on after having the hinges powder coated the back was high for some reason, I couldn't adjust it down without removing the hood and hinges to hog out holes or something so lowering it with a shim was fine with me.



Brian
 
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