hey all,

new poster here, ive owned my 79 Z for a few years now and finally have gotten to restoring it. i have noticed that there is a crack in the tranny tunnel and have seen this on a few other cars as well. is this a common problem? i believe this is from the car flexing and causing the tunnel to crack. how do i fix it/ where can i find a replacement floor for the car? i have done some searching around and was wondering the compatibility of other years. TIA for any help!

thecamarokid79

 

If its just a crack just weld it back up. Your weld will be stronger the the orginal floor.

This crack would have been from some sort of twisting impact like going over a drainage ditch speed bump. Your motor would not have the torgue to do that and there are other places it would crack before the trans tunnel.

 

ok, so would that stop the crack from spreading? im pretty sure this car was beat. it has leaf spring helpers on it and seems to have been run pretty hard. I am thinking i might need a whole new floor as the floor to firewall, rear footwell and a few other spots are rusted out as well. any idea what year floors will work to replace the original with?

 

Yes the weld would stop the crack. If you want to be 150% sure then drill a hole at both ends of the crack then weld the whole thing shut. As a general rule sheel metal is 1010-1020 steel. Thats good for about 30K PSI in strength and med alloy filler wire is good for about 95K PSI. That is why, if it welded correctly, it will be stronger then the factory floor.

 

I thought it sounded weird that the tunnel would crack in the middle of nowhere. The fact that your floorboards are rotted away makes sense of it now. I wouldn't worry about the crack until you replace the floors. The new floor panels will cover some, if not all of the crack anyway.