Hatch alignment

[qz16]

Our project has dragged on way longer than I intended.  It is a 1973 240Z that we call "the bucket".  The car was completely stripped and has undergone a color change, and there was a fair amount of rust that had to be dealt with, so it should not come as too big a surprise that I am having trouble aligning the hatch.  I have new hinges.  The 240z had a single (shock absorber) lift support on the left side.  The alignment of hatch at the roof line is very close, but I need more clearance to close the hatch without damaging the paint.  The problem as I see it is that the hinges have a great deal of vertical play.  Because the original design call for a single shock absorber to lift the hatch the left side sits much higher than the right side when the hatch is open.  The result is that the hatch is actually tilted down toward the right (passenger) side.  I do not have any adjustment left on the right side.  Years ago I remember reading that someone added a second shock on the right side to prevent the hatch from twisting.  I have since found out that the 260z and 280z both had two lift supports, one on each side.  This makes perfect sense to me, given the issue that I am having in that the right side shock absorber will raise the hatch using the play inherent in the hinge.  I am hoping that it will give me enough clearance to clear the roof and then the weight of the glass will force the hinge play to be reduced when the hatch is closed.  

So, my plan is to add a second shock absorber to the right side.  In order to do this I need the bracket that attaches to the body that holds the shock absorber.  The original shock has a bracket attached to it with a rivet type pin.  This end attaches to the hatch.

So, If you have experience that indicates that my plan will not work - please share your thoughts, so I can move on to my next plan which I have as yet not thought up.

If you a 260z/280z RIGHT side bracket that you want to sell please contact me.  I only need the right side bracket, but would buy the whole setup if necessary.  The image below is of a left side bracket - I need the mirror image.  Thanks for your help.
 

Edited September 18, 2021 by qz16

[Patcon]

Are trying to align the hatch with the shock installed?

[qz16]

Thanks for responding. No, I had the piston off, while adjusting.

[Patcon]

But, you couldn't get it adjusted where it looked good? I haven't found the hatch hinges to have excessive slop

[grannyknot]

59 minutes ago, qz16 said:

Thanks for responding. No, I had the piston off, while adjusting.

Have you noticed that one corner of the hatch touches before the other? Possibly a warp in the hatch frame?  I don't have a photo of them but there should be to long thin shims that both hinge bolts go through on each side, are they installed?

Edited September 19, 2021 by grannyknot

[qz16]

Thanks to both of you for responding. 

Charles,

The hinges are new, but they have a fair amount of vertical rise.  It may not be excessive and I do believe that the hatch may be warped/twisted, so I do not believe that it is the fault of the hinge.  With the piston install as possible, but in the middle of the hatch it is just too close to clear the roof.

grannyknot,

I do not have the long shims but I have used half shims ranging from 1/32 to 6/32 to no avail.  the issue is always the same, a couple of 32nds to close to the roof line.  When the hatch is closed, with the shims the gap between the top of the hatch and the roof is huge.  I know I could bring it in a bit with a shim behind the phillips head screws that hold the hatch to the hinge, but the issue is that I can not clear the roof to close the hatch without scuffing the roof paint.  I can't even begin to figure out how to delicately take any warpage out of the hatch and who knows what will happen when the glass goes back into the hatch.

 

 

regards,

ron

[Patcon]

Ron, maybe some pictures would help

Pictures all the way around the hatch...

Edited September 19, 2021 by Patcon

[qz16]

Charles,

Good suggestion - thanks for the interest. I took a lot of shots of the hatch, but realized that your starting point and mine may be different.  To clarify I am not really concerned at this point with the gaps when the hatch is closed.  My first concern is to successfully close the hatch without damaging the paint at the roof line.  I did take snaps of the gaps in case I am missing something that they might reveal.  I do not have the latch hardware installed so the hatch is not shown fully closed.

In this image everything looks fairly good, but as the hatch closes the available space between the roof line and the hatch is reduced to the point where it just barely scrapes the roof, this is the area of concern in the photo that follows later on.

 

 

 

 

 

 

 

 

 

 

 

So, with the hatch shock absorber installed (on the left side (standard for a 240z) the hatch is pushed upward with enough force to raise the hatch within the hinge.  This is actually helpful, I think, on the left side because it creates more clearance to pass over the roof line.  Unfortunately it does not affect the right side and so the clearance is less on the right side.  You can prove this by lifting the right corner up .  It rises approximately 3/16 of an inch, when lifted by hand.

 

 

 

 

 

 

 

The taped area is the concern.  This is where the roof line is scraped as you close the hatch.

 

 

There are no shims installed on either hinge at this point.

 

 

 

The image above shows the hatch open all the way.  I marked a line (bottom-short line) to indicate the height of the hatch.  I lifted the hatch and marked a second line (top-longer) to indicate the height of the hatch when lifted.  The difference is about 3/16 of an inch.

So, here is my thinking.

1. The shims behind the hinge single bolt head either side of each hinge move the hatch toward the rear of the car and away from the roof line.

2. Shims placed between the phillips head screws and the hatch move the hatch toward the front of the car.

3. The two larger head bolts on either side of each hinge adjust the resting position of the hatch, mostly up and down, and only slightly left or right if at all.

4. Raising the hatch (vertically) when it is in the open position is helpful because it creates clearance to avoid interference with the roof as it is closed.

5. the shock absorber(lift support piston) is stronger enough to lift the hatch vertically.  With only one piston on the left side only one side is lifted and the right side is driven downward.  The right side can't really move downward because it is at the bottom of the vertical travel of the hinge.  Obviously I have no facts to offer as the reason for Nissan adding a 2nd piston to lift the hatch on the 260z and beyond, but since the body of the 260z and the 240z are very similar in this area it seems worthwhile to try adding a 2nd piston to raise the open resting position of the hatch.

6. I was lucky enough to find a pair of 260z hatch lift support brackets and they should be delivered in the near future.

7. While waiting for the 260z brackets I will attempt to align the hatch in minimize the gaps in the closed position

 

Please do not worry about offending me.  If you have a better or more elegant solution, or experience that indicates the above thoughts are foolish please advise as soon as possible.  I am getting older by the minute and need to get the bucket on the road.

 

Thanks again, to all for your help.

regards,

ron

 

Edited September 19, 2021 by qz16

[Patcon]

If you can get the hatch closed without paint damage, post a picture of how the lower edge lines up with the rear of the car

 Also inspect the hinge tabs that are welded to the hatch. The welds can fail and the tabs can move, making adjustment more difficult

[qz16]

 

 

 

 

 

 

 

 

 

 

I am going to have to move the hatch toward the front of the car.  More on the right then the left, this i fear will only make the clearance issue worse.  I also hope that adding the weight of the glass will not impact the lift of the piston.

By inspecting the tabs I gather you mean remove the hatch completely or can i just take the screws out and get one hinge out of the way?  I guess I really need to look at both sides of the hatch tab.  Thats going to take a bit of time as I will probably need a second set of hands to remove and install the hatch.  I will post images of the tabs when I have them.

Thanks again.

 

edit:

Okay so I just took a look at the tabs and they are painted, which means they got a good look over when I sanded them before I primed and and sprayed color.  I am fairly certain that they are in good shape. I probably would not have noticed if they were slightly bent, but a bad weld would not have escaped me.

 

Edited September 19, 2021 by qz16

[grannyknot]

So in this pic, is the tape you have on the rear roof edge getting marred or scuffed up by the hatch as it passes over it?  It is one of the tightest clearances on the body and as much as we all like to have perfect gaps on every panel the guys on the Datsun assembly line weren't so particular.

Great looking paint, did you do that yourself?

 

[qz16]

Yes, the hatch just nicks the roof where the tape is.  I don't need a lot of clearance at this point but you can see from the other pics of the closed hatch that I need to bring the hatch more toward the front of the car which will likely cause more of a clearance issue.  I would like to get the gaps to look good but I am not a perfectionist.  

And Yes I plead guilty on the paint.  It still needs a final buffing.  Thanks for the compliment.  I love to paint.  This is the 2nd car that I have done.  My first was a 1974 MGB, that I still have.