I recently bought new tires for my 84 trans am since the ones that were on there had flat spots and made the car shake like crazy. So after getting them installed now I can hear and feel a tapping sound under the floor of the front passengers side. It doesn't seem to coincide with the speed I'm going so it's not like there's something stuck in the tire. I'm not sure if it could be an issue with the suspension or maybe something underneath that's hitting the floor so if anyone can point me in a direction I should look, I'd appreciate it.

Ben

 

Did the technicians maybe move the catalytic converter when they were putting the car on the lift? This is the only thing I can think of that's under the passenger floorboard. The Y-pipe does come pretty close to the lower control arm as well; at least on my '85 car. So if the exhaust system got touched at all when the car was going on, or coming off the lift, that could be the cause.

 

I did have a rattle underneath that they said was a pipe I think between the catalytic converter and the engine so I'm guessing maybe they moved something when they replaced that pipe. I'll look underneath again tomorrow and take it back to the place if I can't figure it out. Thanks for the info. I'm just hoping it's not a ball joint or something like that.

Ben

 

It's almost certainly loose exhaust component or heat shield. Nothing else over there.