A B737-300 WAS DISPATCHED WITH A RPTED FLT CTL PROB NOT INVESTIGATED BY MAINT.

Narrative

PROB WITH ACFT LOG: 'AIRFRAME BUFFETING ON LIFT-OFF; THROUGH 250 KTS. DOES NOT APPEAR TO BE ENG RELATED. CREW SAYS IT WAS SIDE TO SIDE MOVEMENT. YAW DAMPER OFF NO HELP.' I ASSISTED WITH ACFT. WHEN I TALKED WITH CREW; FO AND CAPT WERE BOTH VERY CONCERNED. ACFT APPEARS NOT NORMAL INFLT; SIDE TO SIDE MOVEMENT WAS DEFINITELY A FLT CTL PROB. UNSTABLE LATERAL AXIS; SIDE SLIP TYPE MOVEMENT. MYSELF AND FELLOW MECHS; UPON BRIEFING CREW; AGREED TO TAKE ACFT OTS. BECAUSE NEITHER OF US WERE WILLING TO RELEASE ACFT; I REQUESTED; SEVERAL TIMES; THAT A SPARE ACFT BE USED FOR THE FLT. EVEN TOLD THE FLC. MY LEAD MAN OVERRODE MY AND THE OTHER MECH'S DECISION. WE BOTH LEFT THE ACFT TO GO TO LUNCH. UPON RETURN I FOUND OUT THE ACFT WAS RELEASED AND FLOWN FROM ZZZ TO XYZ. UPON ARR AT XYZ THE CREW REFUSED THE ACFT AND THE PLANE WAS THEN FERRIED BACK TO ZZZ EMPTY. MY SIGNATURE WAS NOT ON THE RELEASE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE INBOUND CREW WAS DEBRIEFED ON THE FLT CTL PROB WHICH TURNED OUT TO BE A PITCH PROB AND VIBRATIONS IN THE ELEVATOR. THE RPTR SAID THE ACFT WAS RELEASED FOR SVC AND WAS NOT INSPECTED OR THE RPT INVESTIGATED. THE RPTR SAID AFTER THE ACFT WAS MAINT FERRIED; THE CAUSE OF THE VIBRATION WAS AN ELEVATOR PWR UNIT OUTPUT ROD END WORN BUSHING. THE RPTR STATED THE RPTR'S EXPERIENCE LEVEL WAS 10 YRS AS AN A&P MECH.