1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 336Get this manual
Trim Rod Installation 1Place trim cylinder in soft jawed vise2Fill trim cylinder three inches (76.2mm) from top of cylinder using Quicksilver Power Trim and Steering Fluid or; (ATF) Type F, FA or Dexron II3Install lubricated O-ring to memory piston and place into cylinderPush piston down to level of oil
4Install trim rod into cylinder
5Tighten end cap assembly to cylinder securely using spanner wrench (14 inx 516 inlong pegs)