Topic: 1970 Driveshaft Floor Hump Rubber Plugs

[1970 Snake]

I am trying to figure out what the two small rubber plugs where for on the driver side floor hump of my 70 Mach1.
I have attached pics of these which I took during disassembly. I am also trying to source some new ones for restoration assembly.
Any help would be appreciated.

[Brian Conway]

Aren't those indents where the brake line attachments go ?  Brian

[J_Speegle]

Is the car a California delivered car originally?

Need to check some pictures

[1970 Snake]

No to both responses, the screw holes for the brake line are beside the plugs please look at pictures, and no the car is an early built Sept 4, 1969 Dearborn built car.

[1970 Snake]

Would it have been possible that these holes where originally designed for attaching the rear brake line with those clips that you press the center in like the one on the fuel line, and is it possible Ford or the assembly line opted not to use those and plugged them and put screws in instead to hold the brake line like the rest of the line?? It just seems odd that the screws are directly beside the rubber plugs.

[J_Speegle]

Would it have been possible that these holes where originally designed for attaching the rear brake line with those clips that you press the center in like the one on the fuel line,

That is what was typically done

and is it possible Ford or the assembly line opted not to use those and plugged them and put screws in instead to hold the brake line like the rest of the line?? It just seems odd that the screws are directly beside the rubber plugs.

From what we have studied and are aware of there was a period of time (fall 64 at San Jose) were apparently they didn't have any of the clips and mounted those lines to the driveline tunnel with retainers and screws. The push through clip holes were covered with a small lump of dum dum.   

For your particular car and plant we would want to look to other cars built around the same time and plant to see if this is what might have been done as one example isn't enough to assume that is what was done in your example - but its a starting point.

Thanks for a build date for your car BTW it doesn't mean that your couldn't have been built for the California market. Saw the screw holes in your earlier picture but since we don't know the history and the condition before you disassembled it those holes could have been added for at least 3 or 4 other purposes I can think of so that's why we asked more questions

[cobrajet_carl]

Thanks for a build date for your car BTW it doesn't mean that your couldn't have been built for the California market.

Yes, both of my Dearborn cars that were sold new in CA have evaporative emissions.

[J_Speegle]

Went through my pictures and found the following for 70 Dearborn Mustangs

Single mounting holes were found from examples through out the year






There appears to be some short periods of time where and additional hole was made and used.


March example with no evidence of a plug like your example shows





Very very early example with a plug like yours



Not sure why the need for a second hole unless it was an issue with the size of the hardware the plant had ordered but there it is. Since it is a very short IMHO period the plug is likely something that was repurposed so you would need to remove one  and measure it to compare it with possibilities. Looks like one of yours is still usable (at least from the top look) and the other may be reusable since the top will not be seen. Not sure what the other ends of either look like

[jwc66k]

The 70 Mustang Chassis Assembly Manual (AM0035, pg40 - drum brakes, pg71 - fuel w/smog) shows a clip (383368-S2) and a screw (55981-S2) used in two of the locations that you are concerned about. Nothing about a plug. However, there is no disc brake drawing, and non-California smog fuel line have a different routing.
(Check the book once ion a while.)
Jim

[J_Speegle]

The 70 Mustang Chassis Assembly Manual (AM0035, pg40 - drum brakes, pg71 - fuel w/smog) shows a clip (383368-S2) and a screw (55981-S2) used in two of the locations that you are concerned about. Nothing about a plug. However, there is no disc brake drawing, and non-California smog fuel line have a different routing.

Fuel ine doesn't run down the middle of the car on any of the factory 70 applications and disc brakes does not change the routing or attachment for the rear drum brakes

[jwc66k]

Fuel ine doesn't run down the middle of the car on any of the factory 70 applications and disc brakes does not change the routing or attachment for the rear drum brakes

.
The 69 Chassis manual shows both drum and disc brake on separate pages, the 70 does not have a disc brake page. I assume that there are few differences between 69 and 70 Mustangs as far as chassis assembly, California smog notwithstanding. The 70 chassis manual does imply/show the smog line running thru the tunnel (not gas), so without our illustrious California smog plumbing, those mounting points would be for brakes only and why a plug was used instead of a screw and strap is a puzzlement.
Jim
(A "backyard margarita" has been finished. It was good. A "backyard margarita" is made from kiwi fruit and Mayer's lemons grown in my backyard. The tequila is supplied by others.)
'

[1970 Snake]

So to be clear my car was NOT built for the California market, it was built for Western Canada, Calgary Alberta to be exact. It also is a power disc/drum brake car.
I have attached pictures before restoration disassembly of the tunnel brake line and the clips used, and you can see both the screw/clips and the rubber plugs side by side in the pictures.
My guess regarding the screws not being put into the plug holes is because the plug holes are to large for the self tapping screws, so the holes where plugged off, and the clip/screws mounted beside them to hold the brake line. Additionally the factory clips are much different in size than the AMK reproductions as you can see they are shorter, heavier, with larger holes than the brake line dameter, and they are factory NOT replaced during the previous owner life of the car. The longer/lighter AMK style clips where originally used for the one in the tranny hump and the firewall area, but along the driveshaft hump they where short as shown in the pictures. I think the general discussion regarding this topic has evidenced that the holes where for push clips as I suspected and Jeff alluded to, and they where never used and just plugged off. Thanks for the input and discussion regarding the topic

[J_Speegle]

.................. I think the general discussion regarding this topic has evidenced that the holes where for push clips as I suspected and Jeff alluded to, and they where never used and just plugged off..............

Didn't mean to leave that impression.

Could not find any examples from any of the three plants that used the push clips for the brake line retainers like we do in earlier years though they were used in some spots for the fuel lines on the same cars.

What I found was that there appears to be a couple of periods during 1970 production at Dearborn where there was an issue (likely with the mounting hardware/screw size) with the attaching hardware where they used a fix

[Armond]

the Boss 9 I am restoring at the moment had a screw mounting the line, next to the original holes, three of them. No plug like shown, but had some sealer pressed into the holes.  So something was going on.

[1970 Snake]

Sorry about my misinterpretation of your comment Jeff, I guess my question still is as first asked what where the two holes intended for, as their diameter is 5/16" and the screws are only 1/4" I measured these with a Vernier and they are definitely not designed for the screws. Am I hearing that some floor pans had these holes and some did not?? Is this an early design for something that was deleted but the holes where punched anyway? These questions have my curiosity and if someone can answer would be great, in the mean time need to find my original plugs, took them out in 2007 during disassembly, they are in a bag somewhere and put them back in the holes as it looks like sourcing new ones to complete my resto will be an issue. Great discussion, I am surprised this topic has not come up before and my car is the only one so far with rubber plugs in the holes.