Alright, so I just got my hands on My '87 trans am. Wanted to check the T-tops and trunk, but they key won't even fit into the socket for either. The rounded key unlocks the car, and the other square key starts the car just fine. Is there a third key used for the trunk and the T-tops? Or is there something wrong with the keyholes? The T-tops are original as far as I'm sure, they show identical wear and there is nothing on the Carfax about a replacement. Should I get a new key made or is there something I can do to open them with the keys I already have?

Thanks!

 

When the cars were new, they came with 2 keys: square for ignition, and a round one for both doors/hatch/t-tops.

If I had to guess, the t-tops have been swapped either due to one flying off the car from not being properly latched when driving, or from someone stealing them (yes, people actually used to steal t-tops off these cars). As for the rear hatch, I'll bet it's either a previous owner that locked the keys in the car and broke the lock cylinder trying to get in, or a would-be thief doing the same. I have 2 sets of round keys for my '91 T/A, as someone replaced the Lexan t-tops with glass ones at some point, and didn't bother to swap the lock cylinders over when they did it.

You can buy a set of new matching locks for the doors and hatch, but I haven't seen anyone selling a set with the t-tops also.

https://www.ebay.com/itm/1987-1992-C...sAAOSwiFFeYcao

Only other thing I could think of would be to find someone parting a car out, and get all the cylinders from them if they all match.

 

Sounds like someone could have also replaced the door lock cylinders and had a key done for just those. All lock cylinders should use the same key.