Gary Lewis Posted September 21, 2018 Share Posted September 21, 2018 If you convert a truck to a hydro clutch I'd recommend using a firewall brace. As for the plastic guard, I've never seen a gray one. All the ones I've seen are black. Perhaps the gray one is from a later truck or is aftermarket, I don't know. But it looks like you have a good one with which to replace it. I actually installed a Terrapin brace in my 1984 when I installed the new clutch master and line, etc. My truck also had the smaller of the two Ford repair braces installed previously...I assume through Ford as part of the TSB some 30 years ago...I dunno really. That Terrapin brace is a lovely piece, well made and plenty strong for the job. I had a bit of an issue with mine as it didn't fit the contours of my cab perfectly. I ended up cutting the angle portion off and then welded it back on at a slightly different angle/location. In any case, it's rock solid now. Edit: Part of my interest in having these parts on hand is that I'm casually looking for another Bullnose project, and having the parts required for a manual trans swap really opens up my options. Back when I was looking for the truck that I have now, finding one with a manual trans was tough. Furthermore, there seems to be way more early Bullnose trucks for sale up here than later, so finding a complete 84-86 truck or parts truck is not nearly as easy as finding, lets say, a 1980-1981. When I search across the country, there's usually lots of 1980-1982 trucks, and then they taper down hard from there. Most of the time, I don't find any 1985-1986 trucks. Interesting on the plastic guard for the steering box input shaft. I assume then that mine is from a different vehicle...I dunno. I'll take some pictures of it when I swap them out, which won't happen until I get my new RedHead steering gear and new steering shaft (later this fall I hope). Now that you mention cutting your brace and welding it back I think I remember that. (Man, what I'd give to be able to remember like I used to. But then, I can't remember how I used to remember. ) Yes, post some pics of the other plastic guard. I'm curious. Interesting on finding the later Bullnose. I'm not in the market so hadn't been keeping track. But I'll start watching. Link to comment Share on other sites More sharing options...
Steve83 Posted September 21, 2018 Share Posted September 21, 2018 If you convert a truck to a hydro clutch I'd recommend using a firewall brace. The Bullnose firewalls were designed for the forces created with a mechanical linkage and are known to flex and may ultimately crack when subjected to the forces from a hydraulic clutch.I never observed that when I converted my '83 (with the '82 body/firewall). https://supermotors.net/getfile/72285/thumbnail/wrong.jpg I thought firewall flex only affected the later trucks with the ZF trans that had such a strong pressure plate - the one that also cracked the front of the trans. I broke the original mechanical pedal bracket that I had converted to hydraulic after several years, but I never noticed any problem with the firewall. https://supermotors.net/getfile/747710/thumbnail/pedals3.jpg The only difference I noticed between the '80-83 mechanical & '84-86 hydraulic firewalls was the dimple/hole for the MC, and absence of the hole for the pushrod. That's another reason I don't think converted trucks need a brace, unless they get a trans with a HD pressure plate. Link to comment Share on other sites More sharing options...
Rembrant Posted September 21, 2018 Author Share Posted September 21, 2018 I thought firewall flex only affected the later trucks with the ZF trans that had such a strong pressure plate - the one that also cracked the front of the trans. I broke the original mechanical pedal bracket that I had converted to hydraulic after several years, but I never noticed any problem with the firewall. The only difference I noticed between the '80-83 mechanical & '84-86 hydraulic firewalls was the dimple/hole for the MC, and absence of the hole for the pushrod. That's another reason I don't think converted trucks need a brace, unless they get a trans with a HD pressure plate. It was noticeable in the firewall of my '84. The seam sealer was split right down the middle, and when the clutch was pressed, you could see the crack open up about 1/16". However, that was only after I removed the original Ford repair brace (the small one). With the brace it was tight. That was with the original 10" clutch, but with only about 35k original miles on it. It was stiff as a brick to push too, so no wonder it put a lot of pressure on the fire wall. When I installed the new 11" clutch with my 5spd swap, the clutch was soft as butter by comparison. I thought the original issue was not specifically with the HD ZF clutch, but with ANY clutch once it got worn and the pressure plate and linkages stiffened up. All of that added a lot of pressure on the firewall. I think if a new clutch stayed new "feeling" and soft, it would likely never bother the firewall. Still, knowing mine was already weakened and cracked (the seam sealer, not the cab) I didn't want to take any chances. The bigger worry to me was water and/or moisture getting in through the crack and causing bigger issues later due to corrosion. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 21, 2018 Share Posted September 21, 2018 If you convert a truck to a hydro clutch I'd recommend using a firewall brace. The Bullnose firewalls were designed for the forces created with a mechanical linkage and are known to flex and may ultimately crack when subjected to the forces from a hydraulic clutch.I never observed that when I converted my '83 (with the '82 body/firewall). https://supermotors.net/getfile/72285/thumbnail/wrong.jpg I thought firewall flex only affected the later trucks with the ZF trans that had such a strong pressure plate - the one that also cracked the front of the trans. I broke the original mechanical pedal bracket that I had converted to hydraulic after several years, but I never noticed any problem with the firewall. https://supermotors.net/getfile/747710/thumbnail/pedals3.jpg The only difference I noticed between the '80-83 mechanical & '84-86 hydraulic firewalls was the dimple/hole for the MC, and absence of the hole for the pushrod. That's another reason I don't think converted trucks need a brace, unless they get a trans with a HD pressure plate. The TSB says it is for 1984-on trucks, but it is really for 1983-on as the 460's and diesels came out in '83 with the hydraulic linkage - and the problems started then, as shown by the master parts catalog entry below. And the TSB doesn't say anything about which transmission the vehicle has. In fact, back on FTE we had lots of people with the problem that hadn't swapped to a ZF, just as Rembrant explained about his. The issue is the direction of the force that the linkage applies to the firewall as well as how large or small of an area to which that force is applied. The mechanical-linkage clutch pedal is part of a large assembly that bolts on in several places. And the rod goes from the pedal in an almost vertical direction down to the bell crank. So the force is in a vertical direction, and the firewall is very strong in that direction. And, the pedal assembly spreads that force out over a large area. But the hydraulic master cylinder bolts on in one small spot, which focuses all the force there, and the force is in the fore/aft direction - which is the one where the firewall has its least strength. Here's the master parts catalog entry for Ford's fix. You can see that there was a small one, E3TZ 7K509-A, and a larger one for "severely damaged" firewalls - E3TZ 7K509-B. Note that both were engineered in 1983, so it seems that Ford knew the problem was going to exist. Link to comment Share on other sites More sharing options...
Rembrant Posted September 29, 2018 Author Share Posted September 29, 2018 I couldn't help but take a picture of this big old Ford at the pick n pull today...it just looks so weird with the fan exposed. Link to comment Share on other sites More sharing options...
grumpin Posted September 30, 2018 Share Posted September 30, 2018 I couldn't help but take a picture of this big old Ford at the pick n pull today...it just looks so weird with the fan exposed. Just needs some wings! Link to comment Share on other sites More sharing options...
Rembrant Posted September 30, 2018 Author Share Posted September 30, 2018 Just needs some wings! I know eh? That thing looks like it's 3 ft in diameter...lol. Link to comment Share on other sites More sharing options...
Gary Lewis Posted September 30, 2018 Share Posted September 30, 2018 Just needs some wings! Yes, it does look like it would take off. But that fan may not be bigger than ours. We just never see them that way? Link to comment Share on other sites More sharing options...
85lebaront2 Posted September 30, 2018 Share Posted September 30, 2018 Yes, it does look like it would take off. But that fan may not be bigger than ours. We just never see them that way? I suspect that that is a Powerstroke of some version since the fan is normal, not reverse rotation. That would also carry a much bigger radiator and an intercooler. Link to comment Share on other sites More sharing options...
Rembrant Posted September 30, 2018 Author Share Posted September 30, 2018 I suspect that that is a Powerstroke of some version... Yessir, '07 F350 Super Duty diesel. Link to comment Share on other sites More sharing options...
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