Installing hatch glass- not working

[fusion]

Is the hatch glass much harder to install than the windshield?  I am finishing up a 1976 280z build and am installing the glass.  I have brand new gaskets from vintage rubber.  The front windshield was a bit off a pain but got it on the first try.  

The hatch glass is seeming much more difficult.  The hatch is off the car and I thought it would be easier to install off the car rather than on the car.  I am using the same rope method.  With the front windshield, I was able to slide the glass/gasket into the lower pinch weld and then use the rope to pull the gasket around the pinch weld and use hand pressure to walk it around the sides.

With the hatch glass, I can't get it started on any sides of the pinch weld.  The top and bottom are especially not very close.  I really don't have a good game plan.   I did have someone helping me.   We gave up after about an hour and no real progress.  When we got one side sort of close, the other side would be going the wrong direction.  I am using 3/16" (4.8mm) rope.

I have seen a couple videos online and they basically just set the glass/gasket into the opening, flip the hatch over and start pulling the rope.  Looks super easy.  Not sure why it's so hard for me.  The glass did come out of this hatch, so I know it was in there before.

The new gasket is very robust and I'm sure making it more difficult, but I believe vintage rubber is generally regarded as a quality manufacturer.  The hatch is awkward to handle and manipulate which isn't helping either.  

Any advice is welcome. 

 

Thanks

 

 

[Patcon]

We did this recently. We did it on the car because it allows you to put pressure on the glass easier. I got most of it in by myself and Cody helped me get it finished. Not as hard as the windshield but not super easy either. Be sure and use soapy water or the precision liquid etc.

[grannyknot]

I've done 4-5 rear glass installs and agree with you, more difficult than the front.  As mentioned by Patcon, hatch needs to be mounted on the car, install the rubber gasket on to the glass, install the SS trim into the rubber gasket.  Lose the rope and get some string trimmer/ weed wacker line, install the trimmer line in the pocket that will go over the pinch weld, lube every thing up, I just use a squirt bottle with water with a small squirt of dish soap.

You really need a second pair of hands, close the hatch, mount the glass on the hatch, snug the glass down on the bottom of the hatch, that the will be the edge that gets installed over the pinch weld first.  The last section of the rubber to be installed will be up near the roof.

One guy is inside the car laying on his back, the other outside. Start pulling the line over the pinch weld, once you have it over the entire bottom lip the guy outside needs to pull the glass down to ensure full contact. It is crucial that this step is done now, once the sides are done there will be too much fiction to adjust the glass.

Once the bottom is properly seated work the bottom corners one at a time, proceed up the sides equally, then the top corners, then the top horizontal section.

On the corners it is helpful to rotate the line in a counter clockwise circle to help the the rubber over the lip without tearing, also, once the rubber lip is over the pinch weld you will want to push/pull the lip down from inside with your fingers so it is fully seated.

[cgsheen1]

The hatch glass is a bit tricky because the end opposite of your pull wants to push out of the hole. We've always done it with the hatch mounted and you really need some help keeping the glass from moving too far opposite of the pull. I used to use very thin diameter cord but found it more likely to tear the rubber if you weren't careful and/or well lubed. I switched to soft "clothes line" (cotton or poly) cord and have been doing it that way for years. It's probably 3/16" or 1/4" and I soak it before use. Easy pull and no tearing. We've done more than a dozen this way. I think my son did one solo one time but I never have...

Granny is correct on the constant pressure, pulling the inside rubber outward as you go. We pull a bit of cord, press the glass down while pulling the inside rubber outward to help set the glass as we go. The farther along you get the more the glass will be able to settle so the guy on top needs to keep going back with pressure while not allowing the glass to move out of the hole. We normally start on the top but I don't think that really matters. We also don't lay inside - you can reach the string pull from outside and it's then easier for the pull guy to pinch the interior rubber to the outside helping to set the glass and weatherstrip into final position as you go. Keeping the glass down in the hole is paramount. Slow and smooth is fast in setting windshield and hatch glass.

[fusion]

Success!  Thanks to everyone for the great tips.  We ended up having one guy in the hatch pulling the rope and using a spudger to pull the lip over the pinch weld.  We ended up needing a third pair of hands as we got to the top so we could have both upper corners of the glass pushed downward as the seal was pulled over the lip.  This was much harder than expected. 

 

I'm not sure how people are able to make it look so easy, especially with the hatch off the car: 

 

 

 

[Namerow]

It would be fascinating to see a video showing how the rear glass was installed at the factory back in the day.

[Diseazd]

Some jobs should be left to the professionals……