Firewall Cracked?

86T-Top

Founding Member
Jun 29, 2001
553
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17
Dublin, PA
Anyone ever see or have a problem where the metal on the firewall right where the clutch cable passes threw broke or cracked. I was trouble shooting a hard clutch pedal and found that when I pressed on the clutch pedal my firewall flexed. I took my cable and firewall adjuster out and found that the metal where the firewall adjuster sits is either broken and bent in towards the car and cracking.

Anyone ever have this problem b4? If so what did you do? For a temp fix I made another plate to put between the firewall adjuster and firewall out of 18 gauge steel to spread the load in a wider area of the firewall. Unfortantly this metal is also bending. :owned:

Mario
 
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The only idea i would have is to make another piece of metal that goes on the engine side of the firewall that would support the load, and drilll/rivet it to the firewall, may not be the prettiest in the world. Other than that id have no clue, that would be a tough fix if it's rusted real bad.
 
Mario, not real common, but i have seen it before. people generally do a reinforced plate like you did, and it holds up.

i have to ask (though you seem like a pretty savvy guy and likely thought of this stuff): how stiff is the clutch pedal? if aftermarket, how is the clutch cable alignment? any bad spots (chafing, etc) as the cable goes near headers, etc? proper routing of the cable? just getting at things which could diminish the pedal effort here.

it would seem like you would have a pretty stiff pedal to tear the firewall like that.

good luck with it Mario.
 
Well there are a few problems with this clutch setup, and the ripped firewall was the result of me letting it go for too long. Here is the setup. FRPP Heavy Duty cltuch. Steeda quadrant, firewall adjuster and adjustable cable.

Two weeks ago I replaced the Steeda adjustable cable, with an Autozone non adjustable cable. I replaced the cable for two reasons. 1. The pedal was extremly hard to push in (Everyone that drives it or trys to drive it complains about it. It is so hard that it hurts my back and leg after awhile, and when you go to push on it your but slides back into the seat and up the back rest a bit)
2. for the past few weeks b4 I replaced the cable I had to keep taking slack out of the cable via the firewall adjuster. I finally ran out of room on the firewall adjuster and the cable below. Upon inspection of the cable I found the the plastic outer shield had split by the bell housing. So I figured that the cable was comressing when i pressed on the clutch pedal, and this was causing the poor adjustment of the clutch. So I replaced the cable and I was very happy. The hard clutch pedal was gone and everything was working great.

Well that lasted for about a week. I checked out the cable this weekend and it looked fine. So i took my firewall adjuster out and I really had to pry on it to get it out. Once it was removed I notice how the firewall was badly damaged.

I was thinking about this more and I think that the problem is with the firewall adjuster. With the stock setup you have the rubber bushing between the cable and the firewall, but with the Steeda setup you just have the firewall adjuster resting on the firewall. With the stock setup the rubber bushing dampens the pressure applied to the firewall and it spreads it out on the firewall more. With the Steeda setup the pressure is put directly on the firewall right by the hole where there isn't much metal. I think this may have caused the split fire wall.

Finally upon inspecting my firewall adjuster I notice that there were grooves worn into it, from the cable rubbing threw it. Unfortantly since the firewall cracked, the adjuster is not sitting level and this is causing the cable to rub the adjuster inside of the car and cut grooves into it.

I plan on fixing this properly by welding up the cracks and rips in the old firewall and then by welding in either a piece of 12 gauge steel or two peices of 18 gauge on top of the firewall. However, I want to know why it ripped. I don't want to do all this work and have the firewall break again. Also to do this I am going to have to take the upper intake off and possilbe the brake booster to get in there with the welder. Ideally I would like to pull the motor to get in there.
 
Also what is the "proper" routing of the cable. I think I have it right, after it attaches to the shock tower, I have it tucked in between the oil pan and the k - member under the motor mount, with a straight shot back to the clutch.

Is it possilbe that I have a bad clutch causing this hard pedal. That was my inital thought, but after the pedal effort went back to normal with the cable replacement I don't think it is. I believe it has to do with the cable not being lined up properly once it enter the firewall and then rubbing on the adjuster. Does anyone agree, or am I wrong. Finally I never got a spacer with my Steeda quadrant for mounting it on the clutch pedal, so the quadrant has some free play in it. Could this cause the problem?



Thanks guys,

Mario
 
86T-Top said:
Is it possilbe that I have a bad clutch causing this hard pedal. That was my inital thought, but after the pedal effort went back to normal with the cable replacement I don't think it is.

I had a similar problem with my 86 Saleen, the pedal effort was rediculous. We replaced the cable, quadrant and put in an adjuster, and it was better for a while. Eventually the cable just gave up... it was a Valeo clutch, don't know if that made a difference or not. I finally gave up fighting with it and put in a new Centerforce II clutch and never had a problem with it after that.
 
Same problem with my coyote swap fox and only answer I get is go auto... But I refuse if you found the answer please share my whole clutch adjustment rip through the firewall and I "fixed" it and have a mcloud hydro clutch and it's looks like it's starting to flex again, no rust on mine at all
 
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If you install a Maximum Motorsports strut tower brace, it'll stabilize that part of the firewall, because it's the only one on the market that bolts to the pinchweld right above the clutch cable hole. I couldn't believe how much that area flexed without support until I saw it myself. It's also a good reason to run a Ford Factory clutch cable and not any of the piece of :poo: adjustable ones that create so much more pull effort. That effort goes right into the firewall.
 
Right on man thanks yeah gunna look in to that might have a hard time getting it to fit over the motor coyote leaves no room under the stock hood, trying to keep it as sleeper as we can but motors coming out again to really see what's going on and to repair wright this time! Thank and if that fits over my motor I'm gunna get one as well for extra strength
 
Well there are a few problems with this clutch setup, and the ripped firewall was the result of me letting it go for too long. Here is the setup. FRPP Heavy Duty cltuch. Steeda quadrant, firewall adjuster and adjustable cable.

Two weeks ago I replaced the Steeda adjustable cable, with an Autozone non adjustable cable. I replaced the cable for two reasons. 1. The pedal was extremly hard to push in (Everyone that drives it or trys to drive it complains about it. It is so hard that it hurts my back and leg after awhile, and when you go to push on it your but slides back into the seat and up the back rest a bit)
2. for the past few weeks b4 I replaced the cable I had to keep taking slack out of the cable via the firewall adjuster. I finally ran out of room on the firewall adjuster and the cable below. Upon inspection of the cable I found the the plastic outer shield had split by the bell housing. So I figured that the cable was comressing when i pressed on the clutch pedal, and this was causing the poor adjustment of the clutch. So I replaced the cable and I was very happy. The hard clutch pedal was gone and everything was working great.

Well that lasted for about a week. I checked out the cable this weekend and it looked fine. So i took my firewall adjuster out and I really had to pry on it to get it out. Once it was removed I notice how the firewall was badly damaged.

I was thinking about this more and I think that the problem is with the firewall adjuster. With the stock setup you have the rubber bushing between the cable and the firewall, but with the Steeda setup you just have the firewall adjuster resting on the firewall. With the stock setup the rubber bushing dampens the pressure applied to the firewall and it spreads it out on the firewall more. With the Steeda setup the pressure is put directly on the firewall right by the hole where there isn't much metal. I think this may have caused the split fire wall.

Finally upon inspecting my firewall adjuster I notice that there were grooves worn into it, from the cable rubbing threw it. Unfortantly since the firewall cracked, the adjuster is not sitting level and this is causing the cable to rub the adjuster inside of the car and cut grooves into it.

I plan on fixing this properly by welding up the cracks and rips in the old firewall and then by welding in either a piece of 12 gauge steel or two peices of 18 gauge on top of the firewall. However, I want to know why it ripped. I don't want to do all this work and have the firewall break again. Also to do this I am going to have to take the upper intake off and possilbe the brake booster to get in there with the welder. Ideally I would like to pull the motor to get in there.
i had the exact same issue,very hard pedal,the firewall cracked also,i put a plate in and reamed the adjuster hole out,worked like a charm!