hydraulic clutch, firewall flex repair
 

My beast.. 84 F250, 460, T19.

Among many other repairs, I'm doing the clutch, pressure plate, throwout & pilot bearings, and surface the flywheel. Also will replace clutch master cyl, slave cyl, and hose. Reading about clutch issues here, I learned about firewall flex. My firewall is cracked 3 places around the clutch master cyl.

http://i629.photobucket.com/albums/u...77_640x480.jpg

Also, the clutch master cyl push rod is seriously worn, as is the stud on the pedal bellcrank arm - the stud is about 1/2 gone..

http://i629.photobucket.com/albums/u...64_640x480.jpg


So, I lurked here a while and found a good post.

https://www.ford-trucks.com/forums/3...forcement.html

I think I will fab the firewall reinforcing plate rather than try to buy it. That doesn't look too hard. I can also weld the cracks in the firewall once the master cyl is out..

So - does anyone have a picture or template of the reinforcing plate? Without having that as guideline, I would just make a plate the same shape but slightly larger than the master cyl. Is this reasonable? Or should the reinforcing plate also go behind the brake booster+master cyl?

I read here that Ford offered two repair kits for this issue back in the day. One for simple damage repair, and one for severe damage repair. My guess is the severe damage kit was just a bigger plate, covering more area. Did it extended behind the brake master+booster? Did it follow the curve of the trans hump?

From what you can see in the pics, is the damage I have considered severe? Is welding up the cracks and going with small reinforcing plate enough? After doing this much work, it seems silly to "half@$$" it.

Feedback is most appreciated. Thanks

I would see if the Ford dealer has any left in stock.

Here's a link with some info.
Firewall Re-inforcement plate - Oilburners.net

Thanks very much. I'll check with local dealer Monday, but his part looks like the way to go. Much obliged.

Apparently that part is discontinued, theres a guy over on OilBurners.net that makes them better than the Ford ones.

Thanks for the tip. The link Franklin2 shared was who I think you're referring to.

Yup, that's him. I have to order one my self for my new cab.

You might check out a thread titled "Frankenstein drivetrain issues" There are some good pic's in there.

I've been reading and wrenching on how to fix this.

I found my way to Terrapin Mfg - http://www.terrapinmfg.com

I contacted Jason, the owner, and obtained one of his smaller reinforcing plates. While waiting for delivery, I wire welded the cracks from the engine compartment side. I suck at welding, but eventually got enough penetration without burning holes that couldn't be filled. It does not re-crack when the firewall is flexed. http://i629.photobucket.com/albums/u...74_640x480.jpg

I got the Technical Service Bulletin regarding "Clutch" from the Terrapin website, and read it thoroughly.

Once the part arrived, I began with test fitting. The 90 degree bend in the flange where the part attaches to the tranny hump would need to bend open a little. The TSB states that the service bracket might have to be bent to fit, which was the case for me. I bent the flange open a little at a time, until it fit flush. On the bench, you can see how much bend it took for a flush fit. Instead of a 90 degrees,about 75 made it fit nice for me.
http://i629.photobucket.com/albums/u...78_640x480.jpg

I did not have to hammer the firewall at all to get a good fit. Just a slight change in the bend. Bolted the part in, & drilled the extra holes using the part as template. I only screwed up 2 out of 4 holes.. (facepalm) But the reinforcing bracket from Terrapin fits nice. http://i629.photobucket.com/albums/u...83_640x480.jpg

http://i629.photobucket.com/albums/u...84_640x480.jpg

My original plan was to try and make this reinforcement bracket out of scrap, but I'm glad I didn't go that route. I'm happy with the part and the good service from Terrapin. It saved me time, and it's of far better quality and finish than I could quickly produce. It's worth the money. I'd recommend this solution for anyone else that has the smaller firewall cracks.

Thanks to franklin2, IDIDieselJohn, ArdWrknTrk for the suggestions and references.

Thanks to Jason @ Terrapin for making a needed part!

I got lucky and the local Ford dealership had one in stock, $15 out the door. I didn't feel like fighting to get the hole drilled and bolted in the trans hump, so I welded that, but did the holes for all the other bolt holes around the master cylinder. Worked nice, but be aware the studs on the master cylinder may be too short, mine were pretty close. There was mention of extenders in the kit, but they were extra.

My Ford kit came with longer studs.
In fact, I just saw the shorter ones when sorting through my 'bin o' bits' the other day.
Excellent follow up axman. Great photos.
Rep sent! :)

Great post Axman. Unfortunately I am facing the same repair on mine. I do not have any cracking yet but I am getting some flex so I am afraid it is just a matter of time. Better to fix it in the summer than try and do it in the winter.

Yep the smaller of the two kits are still avail, at least at my local ford dealer...Jim Babbit Ford in Flagstaff, AZ. As of 3 weeks ago, the kit was around $16 and solved my rough shifting issues. I too was thinking about making my own bracket, but the $16 was money well spent.

i fabbed my own reinforcement plate for a couple trucks. i took 1/4" plate steel, one piece from behind the brake booster extending all the way over to that metal lip just past teh clutch MC. you'll want to bore out the holes in the original sheet metal to a size that your nut and socket can slide through, otherwise your studs are too short. with the plate supported ONLY behind the brake booster, it had enough strength to not flex when pushing the clutch, but for good measure i think i added a couple bolts into the sheet metal. this was before i heard about the FoMoCo kit, but i would venture to say that my design is equal or better in terms of performance

I am going to check the local Ford dealer and see if they possibly still have a kit on the shelf. $16 sounds good to me and I try and buy most of my parts from the JY. A lot of guys on the site can probably fab one up for less than $16 but I am most likely not one of them. I am sure I could make something work but the frustration alone is worth the $16 to me. I have to replace the slave cylinder soon anyway so might as well fix it right and take care of the flex at the same time.

If your fix puts the plate under the hood, this will space the clutch master out that much, and one of the adjustable pushrods for the master cylinder will be a must, or your clutch pedal will be too low.