Last spring I purchased a ‘75 coupe driver and over the winter I decided to replace the interior as a little project with the kids. I have a ‘69 coupe that I restored 20+ years ago and I have probably never driven it with the rear window in, so I decided I would retrofit the ‘75 to have a removable rear window as well as part of the interior work. This project is relatively easy since even though GM stopped offering the removable rear window in ‘72, the body remained the same through ‘77.

I am about halfway through the project, so I will try to update this thread until the project is completed, but here is what I have come up with so far. Thanks to Ernie for helping me with this project. All of the parts for this project are available from Willcox.

Parts required:

1. Removable aluminum rear window frame
a. From what I see these are only available used as of now. I may never get one for the ‘75, if I think I may need one I will use the one for my ‘69.
2. 68-72 rear window weatherstripping
3. Rear window locks (2)
a. These are the chrome latches that mount to the rear of the roof that snap into place to hold the window tight.
b. Each of these is held in place by two ¼-20 ½” pan head screws
4. Rear window lock bezels (2)
a. The trim pieces for the locks above.
b. Each of these are held in place by two screws, on my ‘69 they are ½” approximately #12 pan head sheet metal screws, but they may not be correct.
5. Rear window plastic guide (2)
a. These receive the two pins on the bottom of the window frame.
6. Rear window guide (2)
a. These hold the plastic guides above in place.
b. Each of these is held in place by two 6/32 ½” pan head screws

Parts to be modified:

1. Rear coupe roof panels
a. A notch must be cut out of the rear of the panels for the locks and bezels
b. These could also be purchased, the 69-72 panels will fit and have the notch in them already.

Parts to be fabricated:

1. Two flat metal brackets to receive the screws that hold the lower rear window guide in place.
2. Two (or four?) metal brackets to receive the screws that hold the rear window locks in place.

Alterations made to the car:

1. Two (possibly four) holes drilled in the bottom of the window frame to attach the lower rear window guides.
2. Four holes drilled in the top window frame to attach the rear window locks.
3. Four holes drilled in the top window frame to attach rear window lock bezels.

Parts no longer needed:

1. Non-removable rear window trim.


Here are some pictures of what I have found and accomplished so far. Any comments or advice is welcome.



Here is what the lower window frame looks like once the original window is removed on the '75.



1975 lower rear window frame as found.

The flat spot and notch to mount the lower window guides are there, just as on the '69. The '69 differs in that it has a reinforcing bracket riveted to it to receive the screws.


1969 lower rear window frame as found. (with window guide removed)


Here is the upper rear window frame on both the '75 and '69, as you can see they are similar, but the '75 is missing the reinforcing bracket.



'75 upper rear window frame.




'69 upper rear window frame showing bracket to mount rear window lock.


Here is a bracket I fabricated (left) to mount the rear window guides, it is made from 1/8" steel.



Fabricated bracket (left) and original 68-72 lower rear window guide (right).

Here is an original '69 roof panel, and my '75 roof panel altered to make room for the rear window lock and bezel.



Here is a '69 roof panel (top) and altered '75 roof panel (bottom) along with the bezel.



I am not exactly certain of my plan for the rear window locks. The original bracket is one piece with a bend that allows it to pass over the lock mechanism and is riveted to the body on both sides. My first thought is to have two separate brackets and mount them to each side. I made these from 1/8" steel, they are 1" x 1 3/8" and tapped with 1/2-20 threads and fit nicely on the flat area on top of the window frame. I may add a 1/8" hole to them and then rivet them in place to the frame and install the lock and see how solid it feels. Any advice would be appreciated.



Tentative design for brackets to mount rear window lock mechanism to roof.


Here are the screws from the '69.



Here are the screws used as part of the project, as found on my '69. 1) Bezel screw (these may not be correct) 2) Lower window guide screw 3) upper window lock screw


My 16 year old son is helping me with the project, note the authentic circa 1975 hairdo.



kids nowadays...

 

Hi Scott,
Very nice info in this thread!!!!

I don't know if you've come across it yet but the weatherstrip was held in place in the upper corners with 3 small counter-sunk, flat head screws... almost like a version of a short wood screw. (Typically, but maybe not on all cars?)
These made installing the weatherstrip easier and fastened the corners more securely.

Again... great info for folks to use when adding the removable window.!
Regards,
Alan

 

Alan,

Thanks, I have not gotten to that point yet, the weather stripping is on it's way from Willcox as I type. I will update the thread with what I find.

Scott

 

Alan, I've seen some oddities about these screws... I've seen them on my own car but on the passenger side, I have two on the outside edge of the rubber and one on the inner. On the driver side all three are as yours is pictured. I've also seen cars with 4 screws (not six) and then with six and finally, I've seen them without screws at all.

The NCRS judging guide for 1969 makes no mention of the screws and they are not in the assembly manual for any of the cars 19688-1972. The screws in my car are a tapping type Phillips head screw with a sems washer made to it. I don't think mine have ever been out.

We sell a kit that includes 6 screws to cover us either way the customers car is.

I was also wondering if I could possibly use the weatherstrip picture you have so I can illustrate the location of these screws on our website.

Willcox

 

I will be following this. I have the complete set-up (except for the bracket for the tray latch) for my 1976. My cousin had a 1969 427 Corvette back in the day and I always like the removable rear window! Thanks for any info you provide and good luck with the install.

 

A friend fabricated these brackets to attach the rear window latches to the roof. I have not rough fitted them but I may need to remove a bit of metal towards the rear of the bracket. They are mounted at a bit of an angle and the space is tight in there. I had him make them as close as he could to the top of the latch. If you are interested in getting a pair of these, I can have him make another set within a week or so. Not sure how much he would charge.

Scott



Brackets fabricated to attach the rear window latches to the roof.

 

Great write up on this mod. I want to do this to my 76 as well. I would be interested in a pair for latch brackets your friend made. Would you see what he would be interested in making me a pair for me and any costs. Thanks

 

They look a little high ,compared to the ones I have .











Many years ago I bought a wrecked 74 for parts to resurrect my 69, I never even noticed it had a removable window until I got it home , so naturally I put it in the 77 ,those brackets came out of the 74 all messed as you see ,but they fit perfect as the curve is correct fit up against the top skin