Crack in rear seat area

I have a crack in the transmission hump in the rear seat area. I plan on welding the crack closed. My question is, what caused this? How should I reinforce this so it doesn't happen in the future? Here's a picture:

Is that a crack or did the rear U joint let go at one time and the driveshaft bash the floor? I'd fishplate some metal over the hole and weld around it.

If it's not a u joint going awry then someone auditioned for Bullitt in your car! Stu

<font size=-1>[ This Message was edited by: CaptVirgilHilts on 4/30/07 8:18pm ]</font>

Strange, I have a similar crack on my 64 Falcon. Wonder if it's some kind of stress fracture. I was just going to weld up the crack myself. That plus my new subframe connectors and I doubt it will ever happen again.

Say jpolakow, can you answer a few questions?

Is that a coupe or a convertible?

Is this car used for road/drag racing?

Are you using coil-over shocks to compensate for sagging rear springs (I think the old NAPA literature used to call them "load leveling shocks")?

Are the floor pans in good shape?

Does the car regularly carry four people? Over rough roads?

That's a crack from a repeated reversing load or at best a cyclic load application. I'd have to look a the first part of the crack under a microscope to be sure, but that chassis has been loaded heavily and frequently.

Help us help you.
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The car is a coupe. I have never used it for road or drag racing, but it's possible the previous owner did. I just discovered it after owning the car for 3 years. The floor pans were in terrible shape- I am in the process of replacing them right now. There were quite a few rust holes in the floor pans. I am fixing the floor pans right now so I want to fix this crack too.

Usually it's just me riding in the car. Also I don't have any coilover shocks, however the shocks I have could probably use replacing.

I would like to know more about what kind of loads are causing this, and some ways to reinforce this crack area to make the body more rigid.
Thanks Guys!!

Just replacing the rusted metal in the floor will help eliminate some stress on this part of the drive shaft (drive line) hump. I'd weld in a small patch and move on to something else. Sub frame connectors will help. Take a look at this thread:

http://www.fordmuscle.com/forums/the...html?word=weld
_________________

Beegshot
65 1/2 'stang, Hard Way
79 F100 SuperCab, parts hauler
03 Expedition, grocery getter, kid hauler
Henry Ford said, "If you find you need a tool, you have already paid for it."

<font size=-1>[ This Message was edited by: beegshot on 5/2/07 8:38pm ]</font>

I'd go with that - tack a piece over it. If the car is in otherwise good shape, there's no telling how it got there. The panels might have been under stress for years due to an assembly error or something and finally found relief.

I have a crack in my rear seat area, but nobody wants to see that one...[img]/forums/images/smiles/icon_rolleyes.gif[/img]
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