I also have a '96. Is the shudder intermittent? I've had one from my transmission that occurs when the TCC locks up. Watch the tachometer.... if it drops during (or just after) the shudder, then it's a good chance your TCC chattering during lockup.
I started seeing this at around 60k miles. It has done it ever since, even after replacing the transmission with a rebuilt one.
I've had trouble getting mine fixed, so if this is the problem and you're able to get it repaired, I'd like to know the ultimate cause.