How to Change Your Mercruiser Gear Lube

Step-by-Step Guide

1. 1

   Step 1: Determine what model drive you have.

   Look in the bottom of the bottle.
   
   If you see residue in the bottom of the bottle it should be removed and rinsed out with carb cleaner or Power Tune.
   
   Make sure the bottle is clean and dry. ,,,,, Do NOT reuse the flushing lube. , Never reuse an old drain plug gasket.
   
   Old gaskets get brittle and hard as rock.
   
   Look closely in the hole and use the pick to make sure all of the old gaskets have been removed.
   
   Buy new drain plug gaskets and place them over the cleaned-up plugs. ,,, If you don't, the upper unit will not be lubricated properly. ,,, Be aware that the drive might have an air bubble and that the system might "burp" after being run.
   
   This could result in a drop of the oil level in the bottle.
   
   Just top off the bottle with clean lube and keep an eye on it.
   
   Be sure to loosen the bottle cap to avoid creating pressure in the system.
   
   Pressure in the system will make a mess when the hand pump fitting is removed from the bottom fill hole.
2. 2

   Step 2: Read your owners manual.

3. 3

   Step 3: Buy the correct amount and type of lube plus a little more.

4. 4

   Step 4: Buy a little hand pump that fits the bottle of lube to fill the drive.

5. 5

   Step 5: Place a clean oil drain pan under the drive to catch the old lube as it drains out of the bottom of the drive.

6. 6

   Step 6: Use a large screwdriver and remove the lower drain plug.

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   Step 7: Remove the top oil vent plug.

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   Step 8: Let the unit completely drain.

9. 9

   Step 9: If your drive has an internal drive lube monitor bottle in the boat

10. 10

    Step 10: remove the bottle from its bracket and pour out the old lube.

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    Step 11: If the old lube looks and smells bad it could be an indication of a problem.

12. 12

    Step 12: Inspect the gear lube for evidence of metal particles or water intrusion.

13. 13

    Step 13: If the lube looks bad and you suspect a problem

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    Step 14: FIX the problem before placing the drive back into service.

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    Step 15: If the lube was simply old and smelly it is a good idea to flush the drive one time with new clean lube.

16. 16

    Step 16: To flush the drive fill the drive from the BOTTOM hole with enough lube to fill the drive and then let it drain out fully.

17. 17

    Step 17: Use a sharp pointy pick and make sure to remove the old drain plug gaskets from the drain and vent holes.

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    Step 18: Fill the drive from the bottom-up until the lube flows out of the top/side vent hole.

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    Step 19: Install the top vent plug with the new gasket and tighten.

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    Step 20: If your drive has an internal drive lube monitor bottle

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    Step 21: continue to pump lube until there is approximately one inch of lube in the monitor bottle.

22. 22

    Step 22: Remove the lube fill pump from the bottom hole and quickly install the bottom plug with its new gasket.

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    Step 23: Wipe up any residual oil.

24. 24

    Step 24: If your drive has an internal drive lube monitor bottle

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    Step 25: add lube to the bottle up to the "full" line.

Detailed Guide

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