One problem related to vehicle shudder has been reported for the 1997 Subaru Legacy. The most recently reported issues are listed below.
Oil leak from crank case seal drips back onto exhust manafold during normal driving. Once car has stopped and is at idle the oil burns off the manafold and large amounts of smoke pour from under the hood and under the car. If ventilation system left on then smoke enters the passenger compartment. Number 2: the car shudders when turns left or right at low speeds (5mph). Number 3: the metal guides for the side window (drivers side) have scratched the glass and it can't be repaired must replace. Number 4: car started to sputter or miss after 61000 miles. It occurs only after the engine warms up.