Floor/torque box/frame rail
 

So I have searched and am surprised there's not clear info on the torque box and frame rail repair that is so so common for the firebirds.

So i'm learning it mostly on my own, finished welding in the passenger side torque box today yeha! gotta do both sides.

I'm doing it laying on my back, no fancy stuff here. this is a do yourself thing not professional here likely better ways but sharing what I'm doing. that said i'm not a newbie and know what i'm doing.

what iv'e learned: remove the floor pan/torque box/frame rail portion as one piece. that is if like mine, you only need front frame rail repair. the torque box is spot welded to the floor pan to difficult and not worth the expensive bits to try and remove all the spot welds. of course its spot welded to the rocker and the frame rail to the torque box as well.


use a small drill bit and drill from the bottom along the torque box. make your line inside and using a cutting wheel cut thru the floor along the torque box fwd/inboard/aft areas then I used an air chisel from top along the rocker and broke those spot welds loose. out it comes.

I ordered the under seat pan and rear floorboard and cut to use only what I needed to replace the floor above the torque box first. then welded in the torque box after adjusting for best fitment. next is my short frame rail repair splice. I ordered full frame rails because it was cheaper than just repair pieces. i'll cut em where I need to.


made some measurements as well as checking level from one side to the other. do one side at a time of course. lotta labor but sure feels good to have that strong new metal in there! I overkill the welds. twice as many welds as the factory did. I use por 15 everywhere I can as I go.


not after pretty just strong and straight. non visable stuff is fun! my cars a driver/race so no concerns there. but I dpnt want ugly either. ha. anyway just sharin maybe help someone else.

.....as the process continues
 

It actually didn't occur to me that I suppose I'm lucky not to have more rust on this car than what it has beings it was bought in Omaha Nebraska and stayed there till I bought it. Thought about that while doing the unpleasant on my back brush on Por-15. messy stuff ya gotta stay outta the way of while applying! but its great stuff. Going to undercoat it after this as well.

Getting ready to do the drivers side floor above the t-box/T-box/frame rail i'll take some pics as I go.

This is a street car do it yourself clone project that my goal is to have no more than $20,000 in, going to drive the heck out of it and race once in awhile. started nov 2016 goal is complete in 2020.


I found this copper rich weld thru primer at my auto paint supply store. expensive but good stuff.

removed the drivers side today. cut the straight areas from the bottom, drilled guide holes where I had to cut from the top. I stay back and inch from the aft floorboard seam so I can overlap that with the new floor patch panel. the seam line is a good guide to cutting the frame rail also. air chisel the welds on the rocker side and out it go's. three chunks of sandwiched rust!

I will be helping my buddy do some repair on his rear frame rails soon and this information will really help. Thanks for posting.

couple more pics. where I cut the frame rail. side benefit is I had a seat belt bolt seized up and the new torque box replaces that.




trunk floors good. drop offs and other areas are not. this car has some rust where it shouldn't you would think and zero rust in areas you would think it would.

Looking good!

welded in the floor above the torque box and torque box. just the frame rail splice piece to do and its on to pieces that will move along faster and easier not having to be on my back so close to the bottom of the car!

lot more room to work on the rest of it. felt like my car had a decent amount of rust but after watching others new purchase threads, i'm sittin' pretty good! i'm applying multiple coats of por 15/weld thru primer/undercoat when i'm done with an area. triple the welds as the factory as well.

they don't make a torque box floorboard piece so I bought the under rear seat and the rear floorpan even though I only needed small pieces of each. the fun part is rustproofing way beyond the factory efforts preserving things another 45 years and beyond.


I can't imagine paying a body restoration shop to do this work, would cost a fortune its definetly labor intensive and I can see now how a restoration shop would ka-ching the cash register on ya for 60 plus grand!

wow finished up the drivers side torque box/frame rail/floor board today! both sides done, holy smokes that was a lotta work laying on my back with the car so close above me. rich guys got it made doing that on a rotisserie! burned a hole right thru my 2 shirts with weld spatter once, that'll always wake ya up.

time to por 15 and seam seal all the welds and gaps then por 15 over that. feels good, the area is much stronger than factory with all the xtra welds I added. peace of mind come track time.

drivers side was more of a challenge as the frame rail shape was poor. had to cut it in several spots and fabricate (rebuild) the dang thing. the passenger side was to good to be true, no issues and great fit.

sometimes i'm pretty sure when you order a pair of something, the vendor toss's in one good one and one that's known to be bad to get it out of stock. coulda shipped it back but then that would have shut me down. times to valuable.

thought i'd post pics of my restoration process.

interior dash etc, trans am dash bezel is my prototype deciding if I wanted a 2 hole or 4 hole bezel. decided 2. (no ac bezel) and speedhut gauges. original dash no cracks, switched glove box door and drivers panel to no a/c versions. no ac fiberglass firewall cover.

kind of driving I do, manual front disc rear drum brakes are great. tossed the ugly brake booster. installed a repop auto trans brake pedal for a 69 firebird. direct bolt in, has the extra hole for manual brake. removed windshield squirt setup. blocker kit mod on the scoop.

few repair welds on the wheel wells and core support and por 15 applied. car sat since 1988, had this vintage sanyo 8 track in it, got lucky it was a fit that didn't cut the dash openings any. new heater core refurbished inside heater box fabbed a plate to block off the previous front opening for the a/c duct work.

restored the front bumper, filled the bumper jack slots to clean it up beings the car won't ever see a bumper jack again. new danko flares and spoiler. very impressed with the fit. restored the valance, welded the early brackets to the new fenders for the valance.


whole lot more completed, currently getting ready to replace rear frame rails with a repair, then on to the tail/outer wheel house and quarter skins. goal is to complete all metal work next 6 months and begin final body work this year.

restored tail lights, grills, repop shaker scoop, original front fender scoops from ebay, and anything else removed. floorboards were really good, both fronts only needed this triangle shaped area where Nebraska snow covered feet allowed water to collect to. had to get the big floorpan just for these pieces. everything trimmed to exact fit, butt welded not overlapped.

doors completely rebuilt/ restored, cut out the heavy sidebeams, mirrors restored and anvil auto manual drivers and passenger mirrors installed to toss the octopus cable.

these are the same engine. offered my 69 Judge clone for sale with/without the black version, fella chose without called me a week later wanting it. hes since had len Williams in Oklahoma build him an awesome 455. anyway the Pontiac blue version is the TA clone engine, mellowed out some. no headers, performer rpm intake, holley 1,000 cfm carb, smaller fuel line (to start with) and mechanical fuel pump. plan to mod it to fuel tank with built in electric pump later on. gotta save some fun for later..... out with the original rear, moser awaiting with new 4 leaf springs, global west subframe connectors. got a great black Friday deal from moser! plus they raised there prices after the first of the year, whew.


been applying decals as I go to decide what I want. the originals for a 72 are small, thinking I like the bigger versions for now but I dunno. that's the fun of a clone not trapped to originality. guilt free modern mod upgrades.

brief history, was the most enjoyable road trip to get a car me and my wife ever went on. lol been many, some duds. watched the car on craigslist for 6 months. started at $6,000 slowly went down to $3,000 which is what I bought it for. sold the drivetrain/new exhaust and other un needed non trans am parts so I began the restoration with just $1,500 in it. complete car.


few more pics as purchased and the white pic is to be the end game.


cruise route 66 and 12.30's at the strip is the vision.

removed the screw on panel at the base of the rear windshield today just piddled a bit this weekend. zero rust there nice and dry. zero rust at the top of the cowl and base area at the front windshield to.

began the rear frame rail splice repair. same process as the front rail portion. tried to get away with just removing spot welds but the lack of space on the inboard side and trunk pan didn't allow for room to get in there and knock things loose. my trunk pan is also rust free and good but have to get the section out to remove the rusted rail. no big deal, easy to fab my own trunk panel there. this will go much faster than the front with no torque box to replace.


being a clone the trunk lid doesn't stay up with the spoiler, I noticed the different notches for the torsion bar, I really don't care but if its easy to move the rods to another slot to achieve the lid staying up with spoiler i'll do it. saw a youtube post on that somewhere here.

I have the inner and outer complete tail panels. I will be cutting them and splicing in only the areas in need of repair. its the lower areas as usual on these cars. no need to tear everything apart and replace the entire panels creating much more expertise, alignment issues and work. I like keeping the cars "square" areas as its much easier to follow the original lines. done properly it won't be noticeable. as with the rest a heavy dose of grinding/por15/seam sealer/undercoating ensues as it go's together.

Really impressed with the way you're getting things done, nice work ! Keep posting!

Looking good ... nice shop too :)

never get tired of watching this. If I had the bucks my car would be capable of this to. yeha!

https://www.youtube.com/watch?v=GNfK3TRs1N0

ode' to a clone restoration
 

fabbed up trunk floor panel(s) above the area I needed to cut to replace the rear frame rail piece. had to fab 2 separate panels and weld together due to the shape and bends. got it completed. then welded the bumper bracket on.

the frame rail is just up there as I adjust for fit and proper location, have not welded it up yet. initial fit looks very good! happy about that i'll take all the ease of install I can get when dealing with repop parts.


sprayed the area with rustproofing copper rich weld thru primer. the rear rail has several open tooling holes i'll be able to spray undercoating thru when completed. I used 16 gauge thick steel sheet for the fabbed floor panels, a bit thicker than OE to make that area stronger.


the nasty rust side is the trunk drop off and quarterpanel. leaving them attached so I could be sure and get the size and bend flange in the right place for he new drop off panel. I don't remove any metal until i'm actually ready for that specific area. always saving reference points.

gradually covering the shop ceiling with stuff. preferably Pontiac stuff!

fixin to spray the moser rear with black epoxy primer as I plan to install it as soon as I get the rear frame rail repairs completed. get it back on 4 feet for the first time in a year.

the tail and outer wheel houses, quarter skin will be next so don't need the rear up so high and might turn my attention to a few mechanical items and tak a break from the metal work just for a bit.

really seeing the light at the end of the tunnel now though even though I have likely 2 years to go. that's because from late may to end of august I tend not to work on it as much with summer activities and such.

A friday off work for beloved shop time
 

completed the drivers side rear frame rail replacement today. it fit great, but needed cut a few places as required. I spliced mine over the existing good portion of the frame rail by around 3 inches. by cutting each side of the new piece along the edge equal distance it allow the repair piece to flush right up. weld it all closed and its done. In keeping with my overkill ways I doubled factory spot/plug welds and then welded it solid at the entire edges. super strong. maybe better since i'm using subframe connectors anyway.

on to the passenger side now! will be soooooooo glad when the on my back work is done. at my age the hassle is the distance to car is just to far for my magnifying piece in my welding helmet but to far to see good laying my head flat so constantly trying to prop myself up.


can't wait to do the trunk drop offs/outer wheel house/quarter skins. be in a good working position for a change!

Eureka moment weekend! freaking happy!
 

forgive me for all the whining iv'e been doing about being on my back doing all this.....but it sucks!

eureka moment weekend for me so happy! all 4 forward and aft frame rails done. fabbed up the passenger side trunk floor today I do need to weld up the frame rail but that's a piece of cake now. the frame rails between fwd and aft are excellent. water just drains to these areas.


hope someone gets some assist seeing this its same for 70-81. heres a spot for firebird owners to check if you don't know it, looking in the rear wheel well, looking forward where the seat belt bolt is, be sure the skin lap where the torque box and floorboard meet is seam sealed very well! I couldn't figure out how the floorboard hump above torque box got rusted. well thru time the seam seal fails and the tire throws water right up on that spot and seeps right between the box and floorboard.


now I can go several different directions working on the car and the bottom is 100% done! this part was the unseen unsung heroic work to me lol.

think i'm gonna hang the 4 chunks of rusted hades from a tree!

Eastwood internal frame coating is your friend.

https://www.eastwood.com/eastwood-in...z-aerosol.html

Not sure if spraying undercoating in the frame rails is a good idea, you won't get good coverage, and it might hold water.

Very nice work!

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I agree totally. funny timing I just ordered a couple eastwood internal spray coating.

guarantee no ones more a rust proof freak than me, actually I sprayed the copper weld thru, then por-15 everywhere possible, then seam sealer, then undercoating everywhere possible. next I'm doing the internal spray hose coating thing to be sure I got it all.

with all that the kicker is as with most others, the car will never see rain/snow/mud/salt ever again.

outta last a long time. thank you for the nice work compliment I appreciate that!

proly hang the rust chunks from a cottonwood tree so when I mow the lawn I can look up and recall the victory for years to come and watch em rust more. lol (I live out in the country)

Ha! Nice! And yeah, I'm a POR-15 'freak' too!

On the undercoating, I've been using the aerosol bed liners, 'Bed Armor' is the one I use specifically. I use black, but it comes in different colors:

https://duplicolor.com/product/bed-a...oating-aerosol

Goes on smooth if you hold the can a little further away, and more 'rough' when you hold the can closer. Dries fast too.

The regular undercoating washes off with engine degreaser and other solvents, even gas. So I stopped using it.

.

I've used Eastwood's heavy duty anti rust too, it's black, thin, runs into panel seams, and is 'self-healing'.

https://www.eastwood.com/eastwood-he...-in-black.html

The internal frame stuff is green, and you have to be careful when using it, if it shoots out a small hole, it can go everywhere.

You can see some of it on my build thread, but I just spray bed liner over it and it's done. On stuff you don't want to use the bed liner on, wipe off the frame coating or anti rust before it dries.


.

Looks great!

I'm very interested in the tail panel replacement, as I'll be doing the same in a month or so. I also need to replace the inner panel behind the tail, where the rails connect.

Keep up the good work!

here's the spot I was talking about. not in the wheel well meant just forward. you can see where the torque box meets the floorpanel, my car appeared to not have ever had the seam sealed. water gets right between there, bad news. I sealed it up overkill now.

ugly pic I hadn't removed the original undercoating yet at this time. I was thankfull for it though, it saved this car. the needle scaler made easy quick work removing it.


be a bit before I get to the tail panel. decided I want to get the rear back under it, swaybar and such. do some mechanical and take a metal break.

I will be just splicing in both inner and outer tail panels. neither need full replacement.

darn flu plague ran rampant here took me outta commission last weekend. finished the passenger frame rail and decided to take it easy and worked over the trunk floor some. it is solid just needed a good scuffing. por 15 on everything. looks like a bunch of dirt in the por 15 with it being gloss version but its just the rough texture trunk spatter. when I put new spatter down it'll be nice. por 15 on the new frame rail repairs also. then i'll seam seal the welds, por 15 again, and "fog" the rails inside from front to back with the eastwood stuff.

same ol' ralley 2's
 

so awhile back I restored my ralley 2's. burnt out on em' so tried to spruce em up into something a bit different. still just not into em and will probably go with cragars. love the new cast honeycombs but not the size. maybe i'll get over that I dunno. I ordered the 'bird center pieces that are for other center caps and ground the slots in em' to fit the R2 caps. just trying to make them look different than all the routine R2's. might paint the lug nut centers black and see if I like that. or the center slot lips in black instead of red might work also. ugh! searching for a wheel. my car will be white so thought the red might give it an all American red-white-blue touch.

Looking real nice. Been going thru the same metal repairs. First time welder but I have a lift. Only had a very small section of the rear pass frame rail to fix. I'm on the door rust now. Por-15 is everywhere on my project as well.

Inner Tail Panel Complete
 

Decided to complete just the inner tail panel before installing the differential due to not wanting to possibly have to work around the rear portion of the leaf springs.

the original inner panel is solid less the bottom 2" and where the rusted frame rails ate out the attaching area.

the inner panel sandwiches between the trunk floor and outer tail panel so I was glad I didn't need full replacement. lot more work to do that as the trunk/fuel tank braces attach to it as well. my braces were solid also.

so I used the complete new repop tail panel and cut to what I needed. once I was happy with the butt weld fit, I cut it in the middle to 2 pieces to make it easier to weld up. to flimsy as one piece to handle alone.

Inner tail panel fitment
 

here's where I cut it on the car. hard to get full width pics from laying under the car.

my car has the brown factory primer that makes it look like I left rust behind in spots. ugly stuff. I didn't know about the factory primers and when I first brought the car home and saw areas faded thru I assumed it must have been a brown painted car!


iv'e found that with round sanding discs, then the mini belt sander, then a wire wheel brush, then a needle scaler, you can really clean it up nice in prep for welding and por15. it takes all those to reach the tite curves etc. in fact, the needle scaler leaves a nice mild rough surface behind perfect for adhesion of por15.

inner tail panel weld up
 

all welded up. was very pleased with the fit, layed right against the new rear frame rails. lined it up with the center formed "cup", and fit perfect to my fabbed trunk floor above the rear frame rails. a good repop piece! can't say that all that often.

if ever a place I could have just left the welds as is this would be it beings its cocooned once the outer tail panel is on, but I just don't like leaving my welds undressed. so I do it no matter the area.

inner tail panel done
 

last but not least, the por15 action.

then seam sealer, then por15, then undercoat!

the outer tail panel will be easier, partial replacement there also. moving to the differential install now and the corresponding sway bar/shocks etc.

after that I'll go back and finish the metal work with the trunk drop offs, outer wheel wells, and quarter panels. looking forward to that!

all the underbody of the car is structurally sound now i'm digging that.

Great progress! I would like to know about the stands you're using. Can you share some information on those? Where they came from, brand or part numbers? Satisfied with the quality and stability? I've built my own tall stands in the past, but they require lots of labor hours to hand build. A PM will be fine. Thanks for posting the progress.

ACME tools, sunex 10 ton high height, 239.99 pr free shipping

I was going to fab my own also but for the price of these wasn't worth it. very happy with them, strong and well built. have em on the lowest setting, will go really high.

12 bolt install
 

moved to getting the rear suspension completed. when I was in my 20's I was a weight lifter and amazed my buddies by curling a 12 bolt rear back then! yeh, not now ha. thought of that while hooking up the hoist.

I didn't want the chrome cover showing so painted over it. wasn't pleased with the brake lines moser installed but its not a show car so i'll live with em. the bends were as though whomever did it had no clue. oh well.

rear suspension completed
 

all installed. new axle bumpers, shocks, sway bar, brake lines etc. feeling like a car again.

black rustproofing all done. the black is under rated I say! just because its there doesn't necessarily mean its hiding something. I undercoated after por15 and seam sealer to protect the heck out of it. nothing shady underneath and everything I replaced I welded up stronger than need be to boot. black means your gonna drive it as it should be not a flower pot on wheels.


first thing I did when lowering it down was to check level with all the torque box and frame rail replacement. was nervous about that even though I measured etc during the work, but had never done it so still wondered the whole time. it sit perfect! the level bubble was even dead center. pretty thrilled there not even a slight lean anywhere.


the car sits to high I expected that with no gas tank in and gas weighs just over 6lbs a gallon so won't know what I have till that's in. I do plan on cutting the front coils -the right way- to settle the front down.

cannot find a pinion bumper like it originally had so I plan to use the 69 gto type and fab a bracket.

I welded the upper sway bar link brackets to the frame.

Sweet! Another beast coming back to life.

Keep in mind when you lower the front, it raises the back some. It's a juggle to trim coils and get it 'right'.

Looks great, I'm a fan of the bed liner stuff. (And POR-15).

Welding those brackets is a good idea, since some have pulled those out or stripped the holes/threads.

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Dang, didn't know you were getting a new rear, would have made a couple suggestions. One, ordering it 1/2" narrower on each side takes into account for any future disc upgrades, without pushing the wheels/tires out.

.

yeh getting the ride or stance height I want isn't going to be fun. thought about that, cutting the coils may make it rake forward and I hate that. not doing anything until I get the gas tank in with fuel. I may have to change out the rear leafs and front coils if need be. getting that right is important. seems a hit and miss thing darn it. I have not found any info for the 70-73 as to any "magic" leafs and coils for the right stance. not sure what direction to go there.

I won't be going with rear disc brakes. I even went with manual brakes. had front discs rear drum manual on my 69 Judge clone and loved it. kind of driving I do manual is fine.

the stance is major to me, hate the thought of having to eat my current leaf/coils but bet I have to.

thanks for the input!

When you say 'rake forward', can you explain that? Like, are you meaning the nose slightly lower than the rear?

Since I've been using Global West springs/leafs, never had an issue with rake, stance, or drop, Doug gets it right. A short conversation on the phone, and done. And even if it's a year later, and you get it together and it's not what you want, you can exchange them.

Gotcha on the brakes. I did large drums in the rear for a long time, but there's just such better pedal feel and modulation with discs all around IMO. (for the driving I do)

What kind of leafs and springs do you have now?

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yeh by rake I mean sits higher in the rear than front.

global west is the place huh. awesome, thank you wish I'd have known would have got em from them. I have gw subframe connectors. I got the ones on the car from classic industries. maybe they will work with me on a return.

don't get me wrong, 4 wheel discs are awesome, I just don't need em. I'm in the minority there for sure. I just cruise some and race once in awhile. not into hard cornering and braking.

thanks again, when ready i'll get with global west.