Any one had this hapen?

I was driveing down the high in my 85' Z earlyer and when I slowed down from about 60mph kind of fast becaues the high way turned into a busy intersection. when I layed on the breaks I got a hard vibration let off my foot and put it down and it was gone.
I don't think this could be a frount rotor but it felt like it was coming from the frount.
I have driven cars and trucks with warped rotors and this wasn't that feeling. I think maybe it could be a drum not warped but broke, but like I said It felt like it was coming from the frount.
Any ideas?

i've had a stuck brake caliper create a decent vibration , also check to make sure your front wheels are tight

You are sure your rotors are not warped and the pads are not cracked?

Cracked pad? I'll check for it.
I think it is the alinement or a fu(ked up wheel bearing.
It only does it at a certain speed and when I put on the breaks kind of hard.
I need a d@mn jack, the spare and its jack are gone :mad: .
Good news is I found the RPO codes :cool: .

I had a left front tire go bad on me. At first it would only vibrate under braking, then got progressively worse till it did it most of the time. It looked ok from the outside, but when dismounted, you could see some of the internal cords were seperating.