REV. H ELEVATOR CONTROL SYSTEM - ELEVATOR OUTPUT TORQUE TUBE CONTROL CRANK BEARING, SERVICE LETTER RECOMMENDED MOS I3-JUL-2011 SL 737-SL-27-155 ELEVATOR TAB SOLENOID VALVE REPLACEMENT. SERVICE LETTER INFORMATIONAL MOS I 7-NOV-2000 - (s) SL 737-SL-27-155 REV. A ELEVATOR TAB SOLENOID VALVE REPLACEMENT. SERVICE LETTER INFORMATI