birdcage rust
Thread Starter
Intermediate
Joined: Feb 2012
Posts: 38
Likes: 1
birdcage rust
i am new to the forum and currently own a c5z06. i am in the market for a c3. i stubled across a bb454 71 on ebay and i am interested in the car i dont think its a numbers matching but i am mostly concerned with birdcage rust. this car being a tee top has me thinking that there nhas been leaks over the years, causing birdcage rust. how do i check for this and is ther any other things i should be worried about. i am unable to transfer the link on the car from ebay but the item # is
19cdc5587-D thanks for your help
19cdc5587-D thanks for your help
Pro
Joined: Feb 2012
Posts: 577
Likes: 6
Birdcage rust is best checked by removing various interior trim panels as they directly cover up the birdcage. The windshield header and side trim and kick panels are the easiest to remove on a car that isn't yours yet but you still need to be careful. Pull the kick panels and inspect the body mount pocket and mount itself. If the car has had leaky tops or windshield corners this is where the water and moisture end up. If the seal around the windshield was bad you'll find rust on the frame around it which you can get to by removing the trim all the way around the windshield. It's very hard to see if the bottom of the windshield has been leaking without pulling one or both of the dash knee pads and inspecting the firewall where the upper dash clips.
The ORIGINAL and bestest
Joined: Oct 2000
Posts: 10,009
Likes: 240
From: Toronto Ontario
Toronto Events Coordinator
Wow, second time today I have posted about this! 
I posted this response to a similar thread a few years ago where to look for rust on these cars:
I posted this response to a similar thread a few years ago where to look for rust on these cars:
Originally Posted by 7t2vette
Birdcage:
-from outside the car, look through the windshield at the windshield frame pillars for signs of rust
-with your head laying on the passenger floor, take a flashlight and look up at the lower portion of the windshield frame/cowl for rust; obviously much easier done with the seat removed and/or the passenger side lower dash pad removed. This inspection is more difficult to do on the driver's side due to all the obstructions visually in the way.
-remove kick panels and inspect body mount #2 area for rust damage
-remove rocker trims under the doors, and with a flashlight look up at the lower birdcage from the front body mount #1 all the way back to body mount #3. Do this with the car lifted in the air so you can also inspect this area from the inboard sides of the frame. Pay close attention to the forward portion between body mount #1 & 2. If your windshield seal is leaking and/or your windshield frame is rotten from rust, water will have traveled down the forward part of the birdcage and rusted either the body mount #2 area and/or the area between body mount #1 & 2.
Frame:
-inspect the area where the lower control arms are mounted to the crossmember
-inspect the area of the frame around body mounts #1 & 2; if the birdcage is rust damaged in this area badly enough, then the frame also likely has rust damage, usually on the top of the frame rail where it is hard to detect with the body on
-inspect the entire area of the rear kick-ups on the frame in front of the rear wheels, this includes the inside corner where the side frame rail is joined to the crossmember
I speak from experience; I had to replace my entire windshield frame from the lower hinge bolts up to the center of the t-roof bar because it was so rotten in so many spots! I decided it was faster to do that than do all the spot repairs. The factory windshield sealant had long dried out allowing water to pass. I replaced the windshield frame before I lifted the body, and that's when I discovered the rust damage on the top of the frame rails in the body mount #1 & 2 area that happened because of the rust damage to the birdcage that I didn't see before I lifted the body! I also discovered after the body lift that the passenger side lower birdcage area of body mount #1 & 2 was rotted in an area that is very difficult to see with the body on, it is the area circled in yellow in the pic below of the donor piece I welded in.....the circled area was completely missing!!!! The weird part is that the lower birdcage area of body mount #2 behind the kick panels looked absolutely fine on both sides!
donor piece
existing damage
removed
removed
donor piece welded in
windshield frame removed
windshield frame removed
If I had know what to look for, I probably would not have bought my car! Hope this helps you in your quest for a nice bumper car.
-from outside the car, look through the windshield at the windshield frame pillars for signs of rust
-with your head laying on the passenger floor, take a flashlight and look up at the lower portion of the windshield frame/cowl for rust; obviously much easier done with the seat removed and/or the passenger side lower dash pad removed. This inspection is more difficult to do on the driver's side due to all the obstructions visually in the way.
-remove kick panels and inspect body mount #2 area for rust damage
-remove rocker trims under the doors, and with a flashlight look up at the lower birdcage from the front body mount #1 all the way back to body mount #3. Do this with the car lifted in the air so you can also inspect this area from the inboard sides of the frame. Pay close attention to the forward portion between body mount #1 & 2. If your windshield seal is leaking and/or your windshield frame is rotten from rust, water will have traveled down the forward part of the birdcage and rusted either the body mount #2 area and/or the area between body mount #1 & 2.
Frame:
-inspect the area where the lower control arms are mounted to the crossmember
-inspect the area of the frame around body mounts #1 & 2; if the birdcage is rust damaged in this area badly enough, then the frame also likely has rust damage, usually on the top of the frame rail where it is hard to detect with the body on
-inspect the entire area of the rear kick-ups on the frame in front of the rear wheels, this includes the inside corner where the side frame rail is joined to the crossmember
I speak from experience; I had to replace my entire windshield frame from the lower hinge bolts up to the center of the t-roof bar because it was so rotten in so many spots! I decided it was faster to do that than do all the spot repairs. The factory windshield sealant had long dried out allowing water to pass. I replaced the windshield frame before I lifted the body, and that's when I discovered the rust damage on the top of the frame rails in the body mount #1 & 2 area that happened because of the rust damage to the birdcage that I didn't see before I lifted the body! I also discovered after the body lift that the passenger side lower birdcage area of body mount #1 & 2 was rotted in an area that is very difficult to see with the body on, it is the area circled in yellow in the pic below of the donor piece I welded in.....the circled area was completely missing!!!! The weird part is that the lower birdcage area of body mount #2 behind the kick panels looked absolutely fine on both sides!
donor piece
existing damage
removed
removed
donor piece welded in
windshield frame removed
windshield frame removed
If I had know what to look for, I probably would not have bought my car!
Hope this helps you in your quest for a nice bumper car. 
