What was found
UPON TAKE OFF AND GEAR RETRACTION. NOSE GEAR STARTED TO BANG. WE HAD A GEAR DISAGREE CAS AND A WOW MIS COMPARE CAS. QRH FOR BOTH PROBLEMS WERE ACCOMPLISHED GEAR APPEARED TO LOCK DOWN. (3 GREEN. ). LANDED WITH NOSE HIGH TO KEEP WEIGHT OFF AS LONG AS POSSIBLE. UPON LANDING NOSE WHEEL SHUTTERED FOR A FEW SECONDS WE WERE ABLE TO TAXI NORMALLY BACK TO FBO FOUND NLG STRUT WAS IMPROPERLY SERVICED, SERVICED NLG STRUT WITH MIL-5606 AND N2 IAW CE-680A AMM 12-10-52. PERFORMED LEAK CHECK OF NLG STRUT, NO LEAKS NOTED. PERFORMED LG RETRACTION CHECK IAW CE-680A AMM 32-30-00-720. NO DEFECTS NOTED.