Underbody Rot Problems

[Radiojuke]

I've just picked up my first T-Bird, a 61 convertible. It looks great up top but on closer inspection I find the floor channels(?) that run along side the inner rocker panels are badly rotted from front to back. Can these channels be purchased or do I need to have them made up? Also is there anyone that has some suggestions as to the replacement and/or cutting out of the existing channels. I would think they are integral in the unibody design and I'm wondering if the body will require jigging while I replace them. Any help from the experts would be welcome.

[JohnG]

You are quite correct, IMHO, to be cautious of the channels, first because of the uni-body and secondly because you have a convertible and thus what body there is plays even more of a role in the structural integrity.

I would want to make every attempt to find a shop that had worked on uni-body cars before and appreciated the importance of strength vs cosmetics.

I assume you have collected catalogues from the parts vendors (MAC's in upper New York state for example) to see what body components are available so as to avoid fabricating pieces.

The other thing that comes to mind are: 1) take a deep breath, get a thin screwdriver and lights and see what the extent of the rust really is 2) see if you can figure out what the cause of the rust was - where the water was coming from. On some Squarebirds, for example, passageways for rainwater get clogged with debris, allowing water to be trapped inside, quietly doing all kinds of damage.

I live in New England and have had many rusted, high mileage daily cars. When setting out to repair them, I eventually developed a rule of thumb: however bad the rust appeared to be, it was really at least twice as bad in reality.

A question for the knowledgeable people reading this: are the rocker areas on the 61-3 convertibles different internally than the hardtops? Are they reinforced? I ask this because it is true on the 58-60 convertibles (there is an extensive article on this in the Technical Resources Library, at http://users.wpi.edu/~goulet/TBird/F...nforcement.pdf)

Any comments welcome!!

John

[simplyconnected]

Yes, John. Ford used thicker steel in convertible unibody rocker channels. There are additional reinforcements around the floor pan as well. Convertible rockers can be fixed (let's face it, anything on the body can be fixed).

In other models, Police and Taxis had thicker gauge frame steel. In more recent years, those cars got High-Strength Steel to save weight.

You're absolutely right about the extent of rust, where we live. Guys in the South NEVER buy a Northern car because of the rust. They're smart to stay away because inner panels do a good job of hiding rot. - Dave

[Radiojuke]

Thanks for your help John and Dave. The link and info on the rockers was helpfull. I live about 70 miles north of Toronto and have had my share of rusted out cars. This T-Bird came from Arlington VA. so I was expecting a fairly solid body. I guess the rust issue is common down south also. I went over the underside again with the car on a hoist and the rot is worse than it looks. The rear channel sections are also rotted, though not as bad, and the passenger side is better than the drivers side. It look like these were used as drainage channels as the ends have openings in them. I think I could fab these pieces if their not available.

I've ordered a body assembly manual and hope to find some profiles or cross sections of the rockers and channels pictured in it. If not, I think the profile in the link John supplied can be used. I have access to a break so the fabrication won't be too much of an issue.

I was planning on driving the car a little this summer, while I collected the parts for a body off restore next winter, but this support problem may change the plan. If anyone has done this type of repair with the car still together please let me know, as I would like to collect what I need before I start. Otherwise it looks like the body will have to be put on a rotisserie. I think the easiest way would be to remove the front frame section and mount the body to the cradle at that point and at the leaf spring mounts at the rear. Is this the preferred method? I do have some expierence with restoration but this is the first unibody I've tried to restore so all suggestions will be welcome.

Thanks for your Ideas
Larry

[JohnG]

hi Larry

The only caution I can pass on, and it may not be appropriate in your case, is this. If the strength of the rocker area is in question, then in moving it around I would have some concern about the windshield. In a convertible, lacking a roof, the windshield area becomes a stressed component of the car. The rocker areas were reinforced due to their also being stressed and if one is weak due to rot, more flex can occur in extreme circumstances (like the body being hoisted or rotated).

If you don't feel yours have been compromised in terms of strength, then my comments are all irrelevant.

Some of my caution comes from Alexander, who used to have a horror story or two about Squarebird hardtops made into convertibles by hacking the roof off. They, of course, lacked the reinforcement described in Van Ess's article,and legend had it, not only handled poorly but even had windshields crack while driving!

On the positive side you are working with, in the case of the rockers, straight components, so alignment should be straightfoward after the rot is cut out. Also all the reinforcement (I think) is concealed so you could even excede the strength of the original pieces and no one will see the difference.

It would be nice to find someone who has done similar work on a uni-body convertible to compare notes with, none the less.

Keep us posted! Grab some photos!

John

[Dan Leavens]

Larry: John & Dave have offered some very valid points regarding the inner panels, windshield stress and also the fact it is a convertible.Something that needs to be carefully looked at, moving forward with respect to amount of $$
Living in Barrie, ON. you may or may not have a reputable body shop that can evaluate the work, prior to making a commitment.You may already know someone and that is good but if you haven't, then I would get a hold of Gord at The Southern Ontario Thunderbird Club P) 519-471-8657 ( alt # 905-849-6359 ) or e-mail gord@sotbirdclub.org He or at least some of their members may be able to steer you to a shop that has and does work, on these classics.The other company that is somewhat close, is Royce Auto Service Hornby ( Milton ) , ON. that are a Tbird specialist over the years. Hope this helps, as I am an old Mississauga boy ( Highway 10 & QEW ) that came out west 20 years ago.

[Radiojuke]

Thanks again to all for your recomendations. After reading your comments I've decided against using a rotary mount and also against doing the repairs myself. I've found a restoration shop that has a rack built to fit the T-Birds and Mustangs. He has made up the channels as well as the torque boxes for his previous jobs and is aware of the extra reinforcment required in the rag top. So next week it's off to the shop, and the rebuild begins.

This will mean a change in my plans as I was going to take the car back to it's original colour, Laurel Green. As the colour change would require a interior change I will keep the car red for the time being.

I'll be doing the other repairs as the cars' out of service. the front end, detent, brake lines etc.

Any suggestions from the knowledgable members, about the more common ailment's of this bird that I should be attending to, is still welcome and very much appreciated.

I'll try to post a picture of the bullet bird.

Larry