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MG MGA - Packing between firewall and body

There is apparently some sorta packing material at the top of the firewall between the wall and the body of the car.

It appears that its some sort of horsehair material or something.

Its starting to come out pretty extensively on my car, allowing a bunch of heat to come in.

I see on Moss and Clarke they have replacement felt pads for this.

My question is does the car need to be apart to replace with this? If so is there another solution or do I just pack with fiberglass insulation?

Tysen
Tysen

Are you talking about the sheetmetal piece that is approx 6in by 26in that the steering shaft and accelerator cable goes through?
It is sealed on the top three sides to the frame with felt strips 1/8in thick and 1in wide.
The bottom side is sealed to the top of both toe boards w/felt strips and or sealant.
There are 9 1/4" bolts fron the engine side. 1 1/4" bolt on the top of the tunnel from the inside.The 4 top toeboard 1/4" machine screws also hold it on. with these 14 fastners removed you can carefully pry it loose in to the engine compartment. I believe there was some sort of sealant or glue on the felt originally
To remove it completely to clean paint and reseal you will need to disconnect the steering u-joint and the throttle cable. I don't know if it can be pried past the steering shaft or if the steering tube needs loosened and moved forward. Just looking I would try to pry it past.
With it out replace the rubber piece that surrounds the steering tube.
Randy
R J Brown

Tysen,
Yes a horsehair packing is directly under the cowl. It also tends to disappear when the entire body is chemically cleaned too. It will let hot air in the cockpit and it's best to seal the engine compartment as well as possible.
You will also find this between the wood and aluminum on the bonnet and a strip between the trunk floor and rearmost cowl.
Scott

guys thanks for your comments. Based on that I realized that i didn't describe it exactly and based on that I realized that there may not be a replacement part.

This isn't where the toe boards (i.e. where the steering shaft goes through) contacts with the heater shelf).

This is at the very top. There is a sheet metal panel that runs parallel with the dashboard where all the dashboard cabling runs through. Its takes a 90 degree bend and become the heater shelf. Where this peice abutts the top of the body (cowl) right below the windscreen there is a gap into the engine compartment and there is a horse hair pad that prevents heat from coming in (I believe Scott has it in mind)

I'm missing about 6" directly behind the master cylinder.

How is this replaced? (the replacement peice I mention earlier is actually for where the toe board contacts the heater shelf)

thanks,

Tysen
Tysen

Tysen, if you drive into the cooler part of the year, you can take advantage of the engine compartment heat. I keep that space plugged with strips of old rags until the cold weather comes and just pull them out when the weather gets cold. Very easy to do from under the dash and is very effective. Marvin
Marvin Stuart

Tyson, correct replacement would require at least a partial lift of the body as the strips of packing are pierced by the bolts that hold this panel to the goal post assembly. You should be able to stuff some sort of insulation into the gap but don't use anything that would retain moisture as I've seen some rust in this are on my car.
Bill Young

Tyson, I think I know the area you're describing. I have a coupe, but I believe the sealing in that area would be the same. I've been doing some work in that area recently, and my car has black felt stuffed in the opening you describe. It is about 1/4 inch thick by 1 inch wide. Find something similiar (horsehair may not be original but would probably work). You should be able to fit it in the area behind the master cylinder as the space there is a little bigger than along the middle of the car. It can be worked in with a screwdriver. Also, there is evidence on my car of a sort of seam sealer caulk being used at welded joints under the dash. I believe it to be original, as it is over painted with the original car color. Eastwood sells such a product, part number 31024Z.

George
G Goeppner

I just replaced the body on my coupe and before putting it down , the instructions were to place a preformed piece of cork padding on the frame goal post and also a 1 1/2 x 1 inch foam strip across the front edge of the same goal post area. These instructions came from the kit that I bought from Clark todd. I was successful in sealing the bulkhead to goal post area completely.The cork padding is the same type that goes on all the body mounting joints. If you look at the thread "foam expert" they are talking about the same problem and Oakum (a plumbing joint seal) is the suggested remedy.
gordon

I don't think we are talking about the same thing. The original poster asked about the packing between the firewall and cowl, not the body mounting pads. It is a felt rope packed into a narrow joint. There is also some of this where the trunk floor meets the rear body panel.
John

With the additional explanation on this thread I find that about 6" of the stuff is missing at the left end behind the brake master. Looks to me like the modern way to fix it would be to use a tube of body caulk in a caulking gun. If caulked from front side only it would seal the gap and not create a rust zone.
Bill Young it is not the 1/8 cork on top of the goal post.
Looking from the engine side it looks like it only goes from the hood hinges out to the side of the car. It seals the vertical piece of sheetmetal to which the voltage regulator ,fuse box,flasher etc are bolted to the bottom side of the finished piece the wiper pivots stick through.
Is it two seperate pieces each about a foot long? It looks to me like the cowl and the vertical piece are spot welded between the hood hinges.
More Info???
R J Brown

You are not only keeping out heat, you are keeping out fumes from the engine compartment. That can be an important consideration if you suspect fuel and exhaust fume leakage.

My MGA was completely missing the horsehair matting between the underside of the cowl and the top of the firewall. I resolved my situation by pressing in the packing with a thin stick (an old piece of paint stir stick) and then gluing in place on the interior side with some polyurethane construction adhesive (caulking tube format). This type of glue resists heat well, bonds well to both fiber and metal and is reasonably permanent.

Additionally, as suggested by many folks on this BBS, you could take this same opportunity to cover the ENTIRE firewall, top to floor, horizontal AND vertical portions, with the heat and noise reflective material of your choice. Not only will you then keep out heat and fumes from the engine compartment, but also deflect most of the heat which seems to stagnate under the hood, even when the car is in motion.
Bob Muenchausen

This thread was discussed between 13/09/2005 and 15/09/2005

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