Mercury 200XL Verado Lower Unit Oil Change 

Mercury recommends changing out the lower unit oil on your outboard every 100 hours, or once a year. 

If you've never changed your outboard's gearcase lube before, no worries. It only takes some basic tools and around 10 minutes of your time to change a Mercury outboard's lower unit oil.

Follow this step-by-step walkthrough, and watch our Mercury Outboard Lower Unit Oil Change video above to get this easy job done. 

NOTE: We worked on a Mercury 200XL Verado, but the process is the same or similar for most Mercury outboard models.

Tools and Supplies - Mercury Verado 200XL Lower Unit Oil Change

• Ratchet
• 1 1/16th and 10mm sockets
• Flathead screwdriver

• Gear lube
• Mercury gear lube pump
• Contact/brake cleaner

NOTE: Make sure you use gear lube and not engine oil. Gear lube is thicker and more viscous than engine oil, which is too thin to provide adequate lubrication and protection to the gears within the lower unit.

Changing Mercury 200XL Verado Gearcase Oil

Step 1. Remove the propeller using a 1 1/16th socket.

Step 2. Remove the vent bolt and washer from the right side of the lower unit using a flathead screwdriver.

Step 3. Locate the drain bolt below the prop shaft, and position a drain pan or a similar container under it to catch the old gear oil.

Step 4. Remove the drain bolt and washer using either a 10mm socket or flathead screwdriver. Let the old gearcase oil fully drain out.

Step 5. Screw the end cap of a Mercury gear lube pump into the drain hole, then place the pump into a container of Mercury gear lube, and pump the gear lube into the lower casing until it reaches the vent hole.

PRO TIP: You can use a non-Mercury gear lube pump or even gravity-fill the lower unit, but the Mercury gear lube pump is designed specifically for Mercury outboards, so it attaches easily and makes the job quicker and cleaner.

Step 6. Reinstall the vent bolt and washer.

Step 7. Have the drain bolt and washer ready, and remove the gear lube pump from the drain hole.

Step 8. Quickly reinstall the drain bolt and washer before too much gear lube can drain back out.

Step 9. Clean off all traces of oil from around the drain bolt, vent bolt, and the lower unit itself.

Step 10. Reinstall the propeller and you're done.

Got a little more time on your hands? Why don't you go ahead and change the engine oil while you're at it? Watch the video above to see how to change the engine oil on a Mercury Verado 200XL outboard.