Topic: 1969 Mustang (Dearborn) Underside of tunnel (drive shaft area) sound deadener

[Dirk Pitt]

Question on sound deadener for a Dearborn car built in April of '69 with a DSO of MO (55).  The specific question is if a 428 Mach 1 should have received the sound deadener from the factory on the underside of the tunnel.  I've gotten different input from different judges, all of whom are very well respected for their knowledge of these cars.

Specifically, one judge said that all Mach 1 big block cars got the sound deadener from the factory on the underside of the tunnel.

A separate judge said that the application of the sound deadener was dependent on the DSO and in the case of my car, it would not have been applied (DSO of 55, St Louis).

If it was supposed to be applied, does anyone know how much of the tunnel was covered (i.e. how it was feathered out from the underside)?

Thanks for the input.

[J_Speegle]

From what I've collected (a fair amount considering that this a a Mustang and Shelby fastback detail) the sound deadener application had nothing to do with the DSO nor the size of the engine and is mentioned in the Ford original sales manuals and advertising.  It was just part of the Mach I & Grande package advertised as adding something like 25 pounds of addition weight added to the finish car.

The sound deadener applied to the floor - typically applied to the area roughly behind the torque boxes (rear tip of the transmission in the tunnel area) to the area under the rear seat cushion. This is mentioned in the article you can find in the Library titled "- Undercarriage - Finishes and Sealer Guide for 1969 Dearborn Built Mustangs & Shelby's " page #11. Didn't go into allot of depth but there is some information there also.


If it would help I should have some pictures of some original examples. Often the pattern appears to be three passes from front to rear or in reverse One on each side and one up the middle. The stuff dries out and over the year, sometimes with the help of surface rust under, it detaches and fall off.

[J_Speegle]

As a follow up and as promised to the OP here are some examples of 69 Dearborn sound additional sound deadener applied to the bottom of the main floor panel. The application appears to vary allot depending on the worker spraying the product. Sometimes they started further forward on the torque boxes while other times rearward. Full heavy coverage to a light covering. Miss a spot, no worries. Miss a side or the tunnel - keep it moving. In general from observations it appears that in general the worker stood towards the center of the car and made three passes. Tunnel and then both sides. This often produced deep shadows behind or to the outer side of the front frame rails. Exhaust appears to not have been installed yet but the seat plugs and e-brake cables were.

The practice of applying this coat of sound deadener was done on Mach I's, Shelby's, Grande's and some/many Boss cars for some unknown reason not connected to the interior type. The latter Boss applications puzzle me currently.

Here are a group of cars I'm using for examples today. The production period spans from late fall/early winter through about July.


Starting out with a well preserved example though I wasn't able to get a VIN for this one  Lots of contrast and hard visible shadows suggesting where the worker was standing and how the applicator was angled.

A-1



A-2


A-3



9F143xxx Shows the whole floor section though not as clean or clear ad others. Shows the application all the way to the rear seat riser area of the floor panel




9F1608 Shows that the side passes on this car were started well rearward of the torque boxes and the application passes were applied close together




9F188xxx And April built car for your comparison to your April built car. On this car the tunnel pass was skipped and the worker did not extend rearward the side passes of the applicator

B-1



B-2 This picture shows the shadow of the e brake cable. Also confirms a single pass since multiple ones would have reduced the shadow affect.



B-3 Difficult to see in this picture the applications start on the torque boxes. For others viewing. This car has been repainted and is the reason we see the orange overspray over things like the sound deadener and the fuel line that were not on the car originally when the body was painted




9F2227xx This example if from one of the cars in the unrestored picture section of the site. All indications is that its likely a July built car.

C-1 Very much like the April built car from this angle except this one had the tunnel coated in places as well as some of the rear seat riser area. Nice contrast with the white exterior paint overspray.




C-2



C-3 Forward center section



Hope this helps you and others

[jwc66k]

As a follow up and as promised to the OP here are some examples of 69 Dearborn sound additional sound deadener applied to the bottom of the main floor panel. The application appears to vary allot depending on the worker spraying the product. Sometimes they started further forward on the torque boxes while other times rearward. Full heavy coverage to a light covering. Miss a spot, no worries. Miss a side or the tunnel - keep it moving. In general from observations it appears that in general the worker stood towards the center of the car and made three passes. Tunnel and then both sides. This often produced deep shadows behind or to the outer side of the front frame rails. Exhaust appears to not have been installed yet but the seat plugs and e-brake cables were.

The practice of applying this coat of sound deadener was done on Mach I's, Shelby's, Grande's and some/many Boss cars for some unknown reason not connected to the interior type. The latter Boss applications puzzle me currently.

Here are a group of cars I'm using for examples today. The production period spans from late fall/early winter through about July.


Starting out with a well preserved example though I wasn't able to get a VIN for this one  Lots of contrast and hard visible shadows suggesting where the worker was standing and how the applicator was angled.

A-1



A-2


A-3



9F143xxx Shows the whole floor section though not as clean or clear ad others. Shows the application all the way to the rear seat riser area of the floor panel




9F1608 Shows that the side passes on this car were started well rearward of the torque boxes and the application passes were applied close together




9F188xxx And April built car for your comparison to your April built car. On this car the tunnel pass was skipped and the worker did not extend rearward the side passes of the applicator

B-1



B-2 This picture shows the shadow of the e brake cable. Also confirms a single pass since multiple ones would have reduced the shadow affect.



B-3 Difficult to see in this picture the applications start on the torque boxes. For others viewing. This car has been repainted and is the reason we see the orange overspray over things like the sound deadener and the fuel line that were not on the car originally when the body was painted




9F2227xx This example if from one of the cars in the unrestored picture section of the site. All indications is that its likely a July built car.

C-1 Very much like the April built car from this angle except this one had the tunnel coated in places as well as some of the rear seat riser area. Nice contrast with the white exterior paint overspray.




C-2



C-3 Forward center section



Hope this helps you and others

The pictures confirm that Ford assembly line workers were not the neatest around. The example is also a guide to those trying for a "perfect restoration". That does not exist. Make a "misteak" or two. It's accurate.
Jim