Topic: Fastback Rear Folding Seat

[66TotalPerf]

Hi Everyone,

I've had my '66 2+2 for many years, but never had a rear folding seat installed, always a '66 GT350 rear package tray. I bought a supposedly OEM fastback rear folding seat set, however, the rearmost panel is missing all holes for attaching to the body.

Any idea what application this panel is for? Can anyone share measurements for drilling the holes myself?

Thanks!
Brent

[jwc66k]

That panel is the rearmost section. You can get a better idea of what is required to install stuff by getting a set of 1966 Mustang Assembly Manuals, plus a 64-65 Weld And Sealant Manual and a 64 Chassis Manual.
Jim

[66TotalPerf]

My panel, which I shared the photo of, has no mounting holes. My understanding is that for a '66+, the raised sections of both sides of this panel should have 3 in-line holes to mount to the car body.

I have all assembly manuals and confirmed the mounting steps. In the diagram attached, I don't have the holes in my panel to be able to install screws B, D, K.

I'm wondering if I can drill the missing holes and if anyone has the measurements to assist with this?

Thanks!

[jwc66k]

Now I understand. The lack of holes indicates that panel is probably a 65. I got several things this to do afternoon so it may take a couple of hours before I can measure my 66 GT Fastback.
Jim

[66TotalPerf]

No rush at all Jim. Thanks again!

[66TotalPerf]

Another question. For my '66, any idea where to buy the two parts circled, 11736 and 111B82? I know 111B82 is the rubber stop mounted on the bottom side of the rear panel, however, I don't know what 11736 is.

[J_Speegle]

Another question. For my '66, any idea where to buy the two parts circled, 11736 and 111B82? I know 111B82 is the rubber stop mounted on the bottom side of the rear panel, however, I don't know what 11736 is.

Both bumpers are not reproduced (like never) as far as I know. Only choice would be to find good used one and buy them or borrow them to make molds and cast your own. If you do the later make a half dozen or a full dozen, pick the best ones then sell the other nice ones.

[ChrisV289]

I believe I provided pics of mine on the Facebook page. Appears mine still has the original rubber stop

[66TotalPerf]

Thanks everyone. So those two parts are just rubber bumpers to reduce rattles and avoid scratching the quarter panels?

[jwc66k]

Brent,
I did a mental "walk-thru" of measurements, how to use them and some "quirks". The "quirk" I'm most concerned with are the "cups" that the bumpers from the curved folding sections use as stops. (This is a very late 65 and all 66 design. In early 65 Fastback, it a raised bracket.) It's called "Catch, Rear Seat Back Stop, C5ZB-6360575", item 2 on the drawing in your reply #2. That panel need a "recess" in it for each cup to fit properly. You can't see them on the underside picture in your original post. 
The second "problem" is that to drill holes in the panel you need to drill thru the carpet first, the drilling often "grabs" a section of carpet and pulls it leaving a "scar" in the carpet. I've used a 1/4 inch hole punch to remove enough carpet to successfully drill a hole.
The rear most screw for the "cup", 54511-S13, 10-24X1 1/2 inch Pan head, is 3 inch in from the edge of the chrome and 3 3/8 inch from the rear curve. The recess for the cup would be about an inch in front of that. "Poke" around for that "recess'.
I'll add a picture later.
Jim
Picture added. The red arrow on the right is the "cup". The red arrow on the left is for the front screw (52979-S13, 10-24X1 1/2 inch Pan head, thread cutting) and washer (34970-S, no10 Finishing washer, SST).
(The difference in shade of the panels is "normal".)

[66TotalPerf]

Jim, appreciate the tips and measurements!

the other side of my rear panel does have the triangular cutouts for the 2 Catch plates. Additionally, I have everything stripped off the units as I plan to paint and install new carpet; I only installed the chrome trim to confirm screw holes match.

Finally, I bought all the correct hardware from AMK for the install.

Thanks!
Brent

[jwc66k]

the other side of my rear panel does have the triangular cutouts for the 2 Catch plates. Additionally, I have everything stripped off the units as I plan to paint and install new carpet; I only installed the chrome trim to confirm screw holes match.

That last photo solves a lot (yes boys and girls, it is two words) of problems and questions.
Locate the rear panel retainer first (view DD, item C, C5ZB-63115A60) and get it installed. Make sure screws "D" and "K" (view DD) work
The location of the front holes are, measured with chrome installed (I'm not removing my chrome to measure):
From the side edge - 3 inches; from the front edge - 2 3/4 inches (a sanity check - 10 3/4 from the rear curve in edge). I would use a 1/4 inch dia bit. It looks like you have about 1/4 inch "play" with the washer to cover the hole. The carpet will help.
Back to your reply #2, view FF. Note the welded in "bracket" that the screw, item "B", goes into. You probably need to dill a pilot hole for the 10-24 X 1 1/2 tapping screw into "that bracket". Put a piece of masking tape over "that bracket", both sides. To get the location of the "tap", the rear panel has a 3/8 inch gap between it an the rear folding section in front of it. Cut a couple of pieces of wood 3/8 inch thick (an inch wide, 3 - 4 inches tall) and stick one on each end of the panel to maintain the "gap". Tape them in if necessary. Center the rear panel between the real quarter panels, and align it also with the rear folding section sides. Position the panel as described above and use a "working" ball point pen REFILL (it has a small enough diameter to go thru the hole to mark the location of the hole. Remove the rear panel; use a center pinch to get the "drill spot", drill and tap. Use a no25 drill, 0.149in, and definitely thread the holes with a 10/24 tap. You may have to put some blocks of wood under "that bracket" to keep it flat.
See if it fit. Hoist a beer if it does.
Jim
I added some pictures.
1. The bumper (2 req'd) in the front edge of the folding curved section.
2. The side "thingie" (I didn't remember this guide/bumper at all on my Fastback, but there it is).
3. The rear of the Fastback with everything removed.
4. The upper piece of chrome was very pitted, so I bought a replacement set from NPD. The parts in the replacement set were a lot (see above) nicer but they did "feel thinner". It was about half the cost of getting the original pieces re-chromed, and it is impossible (without a major machine shop at your disposal) to disassemble the long hinge.
5. Same as 4.