Keep in mind that my input is for '67 only.
Rear glass on sedans use gaskets, 2DHT's use sealer only.
I have not done any rear glass work.
But I have done two windshields on the Newps.
Both were original windshields coming out. They both had gaskets, butyl sealer, and 1/2" wide foam tape impregnated with sticky, flexible, almost putty like sealer.
All the interior trim has to be removed as well as the exterior trim and cowl cover(which means the wiper arms come off also). Then if the gasket is still flexible, you can push the gasket and glass out in one corner and then work your way around the rest of the way.
A plastic putty knife works well to get the flap of the gasket started.
I used wood shims to keep the gasket/glass clear of the goop after it was pushed out.
If the gasket is cooked and hard as a rock, you can carefully run a knife around the inside of the windshield frame and cut the inside flap of the gasket away.
I've read that you can wipe the gasket down with something that has lanolin in it to soften it up. I've never tried that method.
New windshield gaskets can be found online.
I went to four old time glass shops and asked about the butyl sealer and sticky tape. They all told me to use only the gasket and not worry about the other stuff.
Since my cars don't get wet unless I don't check the radar before a ride, I wasn't worried about leaking.
To install, put the gasket on the windshield and then get some cord about the same size as the stuff used for pull starting small engines, and run that in the channel that will go over the pinch weld of the windshield frame. Cut it long enough to have a good handle on each end.
Lay the windshield w/gasket and cord on top of the frame. Make sure it is centered and properly set in the bottom channel. Then go inside the car and pull on one end of the cord. It will pull the flap of the gasket inside and over the pinch weld.
Make sure to hold onto the other end or you'll pull the cord out when you get to the second upper corner of the windshield.
Then reinstall all of the trim inside and out.
I was able to remove and reuse a good windshield with no trouble.
The other one had a star in it and I had a brand new replacement to use, so I got impatient and cracked the glass at the star. After that happened the entire windshield cracked all over as I pushed it out. The worst part of all was the clean up of the shards in the dash vents.
The butyl sealer the factory used was stubborn stuff to remove. I scraped as much of the heavy stuff as possible with wood shims to keep scratching to a minimum.
Then after a lot of trial and error, I discovered that PB Blaster work best to remove the residue. The trick is to spray a small spot on a rag with Blaster and wipe a small section. Then go to a fresh spot on the rag and repeat. Too much wiping with the same section only smears the sealer and spreads it out.
The key thing during the entire process is:
SLOW AND STEADY WINS THE RACE
If you get impatient, or try to go too fast, you risk damaging trim, scratching paint, or worst of all, breaking the glass.
Having a helper makes it a lot easier as well.
Hope the input helps.
John
