1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 264Get this manual
Reassembly IMPORTANT: Components must be dirt and lint freeSlightest amount of debris in Power Trim system could cause system to malfunction1Install O-rings and flat ring(s)Apply Quicksilver Power Trim and Steering Fluid or Automatic Transmission Fluid (ATF) Type F, FA or Dexron II on lip of seal
3Install flat ring (if equipped) into groove in each end cap
NOTE: Verify rings are not twisted after installation