What was found
DURING CLIMB OUT MULTIPLE PRESS BUMPS WERE FELT, SMOKE WAS VISIBLE IN COCKPIT. FOLLOWED QRH PROCEDURE & TURNED LEFT PACK OFF. SMOKE DISSIPATED & PRESSURIZATION BEGAN WORKING NORMALLY. PERFORMED WORK ORDER 22195, NO FURTHER DEFECTS NOTED. TROUBLE SHOT LT PACK FOUND LT ACM OVERSERVICED. SERVICED LT ACM TO PROPER LEVEL IAW AMM 12-1-03. CHECKED DUCTING OF LT ACM FOR CONTAMINATION NONE FOUND IAW AMM 21-20-00. OPERATIONS CHECKED LT PACK CHECKED FOR LEAKS. FOUND APU EXHAUST SHROUD CLAMP NOT SECURED BY PASSING EXHAUST INTO APU COMPARTMENT. R & R THE EXHAUST SHROUD SYS, OPERATIONS CHECK & LEAK CHECKED GOOD IAW AMM 49-80-01.