B767 CREW HAD AIRFRAME VIBRATION AND #1 ENG EEC EICAS WARNING ON DEP FROM ORD.

Narrative

AFTER A NORMAL TKOF ON RWY 9L AT ORD AND PASSING 6000 FT WE STARTED TO GET VIBRATION IN THE AIRFRAME. OUR FIRST THOUGHTS WERE OF A DUCT FLUTTER OR OPEN PANEL; BUT THIS DID NOT PROVE TO BE SO. WE SOON GOT THE EICAS MESSAGE L ENG EEC MODE. THE FO FLEW THE ACFT WHILE I WORKED THE CHKLIST; BUT I FELT THAT IT WAS MORE THAN A SIMPLE EEC PROB. SO I TRIED TO CONTACT MAINT CTLR VIA A PHONE PATCH THROUGH DISPATCH; WHICH I NEVER DID GET THROUGH ON MAYBE IT WS A BAD FREQ. SOMETIME DURING ALL THIS; A DEADHEADING CAPT CAME INTO THE COCKPIT; OFFERED TO HELP BECAUSE HE KNEW SOMETHING WAS NOT RIGHT WITH THE ACFT. I ASKED HIM TO BACK US UP ON THE CHKLIST. SHORTLY AFTER THAT WE LOST ALL HYD FLUID IN THE L SYS. AT THAT POINT I KNEW THAT WE HAD A REAL PROB WITH THE L ENG SO I RAN THE SEVERE DAMAGE CHKLIST ON THE ENG AND I HAD THE FO DECLARE AN EMER AND ASK FOR RWY 14R AT ORD WHILE I DID THE REST OF THE CHKLIST. I HAD THE DEADHEADER BRIEF THE PAX AND FLT ATTENDANTS WHILE I WENT BACK OVER WHAT HAD HAPPENED AND BRIEFED THE LNDG WITH THE FO. I THEN FLEW THE APCH AND LNDG BACK AT ORD. WHEN CLR OF THE RWY I HAD THE FIRE DEPT LOOK US OVER AND THEY SAID WE LOOKED OK SO I THEN TAXIED TO THE GATE; PARKED; AND SHUT DOWN THE ACFT.