MECHANIC REPORTS THAT DURING A REPACK OF THE LH MAIN LANDING GEAR SHOCK STRUT ON A DEHAVILLAND DHC-8-400 ACFT; A PRE-MOD LOWER BEARING WAS INADVERTENTLY INSTALLED ON THE NEW SHOCK STRUT INSTALLED ON THE ACFT.

Narrative

DURING THE REPACK OF THE L-HAND MAIN LNDG GEAR SHOCK STRUT ON ACFT X; A PRE-MODIFICATION LOWER BEARING WAS ACCIDENTALLY INSTALLED UPON ASSEMBLY OF THE NEW SHOCK STRUT TO BE INSTALLED. THIS PROB WAS DISCOVERED WHILE ON MY DAYS OFF; AS FAR AS I KNOW. TECHNICIAN Y AND ANOTHER MECH; THAT WASN'T WORKING WITH US; DISCOVERED THAT A MISTAKE HAD OCCURRED. THEY TOLD THE SUPVR; AND ACTION FROM THERE WAS DONE TO DETERMINE THE SEVERITY OF THE PROB. FROM WHAT I WAS TOLD; THEY GOT CERTIFICATION TO FLY THE ACFT FOR 50 HRS TILL THE PROB HAD TO BE CORRECTED. WHEN WE ORDERED THE NEW LOWER BEARING; WE FAILED TO LOOK AT THE EFFECTIVITY. I WAS ASSURED BY A MORE SENIOR MECH THAT THE NEW LOWER BEARING; ALTHOUGH IT WAS DIFFERENT THAN THE ONE WE TOOK OFF THE OLD ASSEMBLY; WAS THE NEW MODIFICATION LOWER BEARING. I WAS TRUSTING HIS EXPERIENCE AND EXTENSIVE KNOWLEDGE ON THE ACFT. FROM MY STANDPOINT; I SHOULD HAVE NOT GONE WITH THE SENIOR MECH AND SHOULD HAVE LOOKED INTO WHY THE LOWER BEARING WAS DIFFERENT. IN THE FUTURE; I WILL BE MORE CAREFUL INSTALLING PARTS ON ACFT AND LOOK AT THE EFFECTIVITY.