A team of forum members (kanvasman - Jim & Lou-Lou) installed a rear window in a Pace Car and this thread shares specific details that supplement some of the online videos that portray the process for members that find themselves in need of guidance. I began this process back in January of this year; that discussion and the preparation are in that thread, referenced here. Thought it best to start a new thread.
https://www.corvetteforum.com/forums...acement-2.html

Window Prep: Kanvasman had previously replaced a window and offered to assist. I took him up on his offer...to avoid his lessons learned. That's what we worked out and share here. The glass and body rear window valley had been cleaned thoroughly with 3M Adhesive Citrus remover. The Zip glass replacement kit was used and included primer, butyl tape and two placement blocks. See previous discussion thread; link above.

Dry-fit #1: With the rear window valley cleaned, the window was dry-fitted with the blocks to get a feel for the gap, top, bottom and sides. The blue blocks are the originals used by the factory; the glass butts up against these rear blocks. Blocks on the side are from Zip; the glass edge rests on top of the block on each side.




Trim Clips: The trim clips were installed. The pin faces outward and punched in with a punch and rubber mallet. The pin secures the other end that inserts into the clip hole. Note: this step not mentioned in most videos.






Primer & blocks: The inside of the glass was prepped with tape to avoid butyl primer dribbling onto the visible surface of the glass. Afterward, the primer was applied to the edge of the glass and to the body surface where the glass will eventually rest. An attempt was made to glue the rear blocks in place...as noted with the masking tape. The body valley has slight indentations to position and mount the blocks. Time was allowed for the primer to dry.




Butyl Tape Installation: The butyl tape was applied to the body surface edge where the primer had been applied; the paper was left in place. Ensure the butyl rides above each block; its best that the butyl is applied as close to the body edge as possible. The Zip butyl kit includes two separate pieces. The shorter we used for the top of the body and ended the tape a couple of inches from the bottom and before the valley begins its journey toward the rear of the vehicle. The longer butyl wrap was then overlapped and applied around the bottom and to the other side.




Glass Alignment to Body Valley Surround: With the butyl in place along with the protective paper, a dry-fit of the glass permitted us to check gaps and align glass to the body. Masking tape was used at top and bottom once we felt we had the gaps spaced evenly all around. A sharper was used to draw alignment marks on the top, both top and bottom.






Dry-Fit #2: We paused with the glass resting on the protective paper and confirming the alignment marks provided the necessary gaps. At this point, with some deliberation, we decided it was best in the final step, to align the rear of the glass with the body and set it down up against the blocks...before setting the front glass down onto the butyl. Note: once the glass sets against the butyl...its there permanently and allows no room for adjusting glass to reposition gaps...videos don't comment on this final step.

Window Installation - Final: With our method of final placment of the glass onto the butyl tape, we set the glass on the vehicle roof; the protective paper was removed and we took a deep breath before proceeding with the final application. Lou provided a critical third set of eyes and hands to ensure the rear alignment was set in place before Jim and I proceeded with resting the glass onto the butyl along the sides and top. If you have followed the steps above, at this point, the glass will rest onto the front blocks with the desired alignment resulting in gaps that are even all the way around.



Hope this is instructive for those 1978-82 owners who have to replace the rear window. Use this along with the YouTube videos to figure out how best to do the installation. We found the third set of eyes is helpful in the most critical step of placing the glass onto the butyl.

 

plus 1 on clips

 

Looks like you guys took the job seriously. I don't see a single beer bottle!

You plan on squirting some windshield sealant in there later?

 

Great thread that will help so many in the future. Thank you!

 

Yeah...beers were afterwards.

We used the butyl tape...not sure what the sealant would add...security? weight?

 

We used it all the time. Same sealant that went on the window opening flange when you have a rubber gasket (55-57 Chev front & back glass for example). Metal car bodies don't have a smooth, even surface that the butyl tape sits on. Overlapping panels and spot welds for instance. The sealant would fill in minute voids. Came in a caulking type tube. I used 3M brand. Lay in a generous bead and use a small acid brush to brush in, somewhat covering the butyl tape. If done with care, is then totally waterproof. Is extra insurance/security.

One of problems with it, is a lot of people were not careful and blurped in bunch, then smacked the trim in place and called it good. Later on, if the glass needed to to removed/replaced, would play hell getting the trim back off without damage.

Corvette bodies may be smooth enough that the tape will suffice. Before you put the window trim back on, do a good water intrusion test with garden hose and sprayer.
RickM

 

 

Lou-Lou is loup68 to clarify things, guys. So glad that we got this done for you, Tom. It was a slightly nerve wracking project to say the least. Once the glass hits that tape, game over! Lou.

 

And I made sure to wipe all of my fingerprints off the glass...in case it does leak. It was a fun project and since none of us knew what we were doing, no one was the boss.

 

If I knew that I was going to have my picture taken, I would have dressed better! Lou.

 

 

Thanks for taking the time to post the details! I'm gonna be going through this myself in the not too distant future and this will be a huge help.

If you had to guess, how much would you say the glass weighs? It obviously requires at least two sets of hands but I'm curious on the weight.

 

I would guess 30-40 lbs but it is awkward to handle. With 2 of us holding it up it wasn't heavy but my shoulders ached the next day because you are stretched out over the car. If at all possible get a third helper. I did mine with 2 of us and it came out OK but was really difficult to line up. You need one person on each side and then one at the back and that was the critical one, since you need that lined up perfectly before you can lay the glass down. And you cannot see those marks from standing on the side. As said, once that glass touches the tape, it isn[t going to move.

 

In addition to the post by kanvasman, the third set of hands, not only aligns those marks, but ensures the glass edge butts up against the blocks...he gently pushes the glass down, holds, so it does not ride up over the blocks, which it wants to do. We caught this in the dry-fit test before we removed the protective paper from the butyl.

 

Great write up/explanation guys. A job I hope to never have to do on 2TONE82! Thanks for sharing.