Author Topic: 67 Fixed Column Firewall Plate (3B633)  (Read 294 times)

Offline Bossbill

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67 Fixed Column Firewall Plate (3B633)
« on: September 20, 2022, 04:18:50 PM »
While searching out the large grommet (marked BD-3512-A) at the base of the standard (spear-type) I also made sure I had the 3B633 steering column opening cover.
The cover has the large opening for the  column and holds a flat rubber gasket (3513) in place in order to seal the column against the firewall. The firewall is also flat where this all mounts.

Although you can't see it in the assy line manual pics, the 3B633 cover has a reinforcement 'ridge' on one side made by a press bending over the area in its center. See pic that shows near where it goes in the car.

According to the bolt witness marks on the plate, the factory had the ridge facing the rubber gasket and the firewall. This almost cut through the rubber gasket. There were no witness marks on the opposite side of the plate so this is how it was installed.
I checked my SJ parts car (built within a week of mine) and found it assembled the same way.

This can't be how it was intended with my hand showing what I think is the correct orientation.

« Last Edit: September 20, 2022, 04:21:18 PM by Bossbill »
Bill
Concours  Actual Ford Build 3/2/67 GT350 01375
Driven      6/6/70 0T02G160xxx Boss 302
Modified   5/18/65 5F09A728xxx 347 Terminator-X 8-Stack
Race        65 2+2 Coupe conversion

Offline J_Speegle

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Re: 67 Fixed Column Firewall Plate (3B633)
« Reply #1 on: September 20, 2022, 06:49:45 PM »
Guess I need to start a new thread on the two different styles of seals and plates used for this purpose from the 65-66 style your car has to the later "67"  and up style used during the year.

Both are related to the style of steering column and steering box. 


Example below



With that said it appears that the engineers designed the plate so that the inside opening was well under the inside radius of the firewall opening and with the lip pointed forward into that opening it forced the seal to turn back towards the interior of the car creating a better seal for the steering columns outer tube as shown in the examples below. This orientation of the plate allowed for a bellowing or curving of the seal towards the engine compartment and then, around the column, back them inward and up the steering column as designed

Believe that is what the pictures below are indicating - that the plate was originally installed as the drawing shows

In the upper right it appears to me that the seal was pulled tighter up the column and against the inner plate. Notice the sharp edge shadow of likely the edge of the plate facing in towards the steering box. While in other examples the gasket was not pulled as tight and they produced a softer curve that was likely the plan




« Last Edit: September 20, 2022, 06:54:27 PM by J_Speegle »
Jeff Speegle

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Offline Bossbill

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Re: 67 Fixed Column Firewall Plate (3B633)
« Reply #2 on: September 20, 2022, 11:08:11 PM »
I understand what you mean about pushing the rubber toward the engine side, but that would work a lot better if the plate ridge area was smaller than the firewall hole.
As it is, tightening the plate really digs into the rubber as it is trapped between the ridge in the plate and the firewall in a number of places.
« Last Edit: September 20, 2022, 11:20:31 PM by Bossbill »
Bill
Concours  Actual Ford Build 3/2/67 GT350 01375
Driven      6/6/70 0T02G160xxx Boss 302
Modified   5/18/65 5F09A728xxx 347 Terminator-X 8-Stack
Race        65 2+2 Coupe conversion