Mercury Tracker 25 Lower Unit Installation

After servicing your Mercury outboard’s lower unit or gearcase, you’ll obviously need to reinstall it back onto the outboard itself, which is pretty easy to do with just a handful of tools and supplies. 

Watch the video above and follow the steps below to reinstall a Mercury Tracker 25 lower unit. 

Tools and Supplies – Mercury Tracker 25 Lower Unit Reinstallation 

Mercury Quicksilver PTFE marine grease

Buy OEM Mercury outboard parts

NOTE: We worked with a 2001 Mercury Tracker 25 EL engine, but the steps are the same or similar for most outboard motor makes and models. 

Remounting Mercury Tracker 25EL Gearcase

Step 1. Lube the driveshaft/input shaft and the water tube sleeve on top of the water pump housing with PTFE marine grease.

Mercury Quicksilver PTFE grease

Step 2. Make sure the shift shaft and the gear shift mechanism on the outboard are in neutral.

Step 3. Apply blue threadlocker to the four 16mm lower unit mounting bolts.

Mercury Tracker 25 gearcase remount

Step 4. Slide the drive shaft and shift shaft up into the driveshaft housing.

Mercury 25 lower unit installation

Step 5. Reinstall the four 16mm lower unit mounting bolts, and torque them to 40 foot-pounds.

Mercury Tracker 25 lower unit installation

Step 6. Reinstall the shift shaft retaining pin, and push the retaining clip back over the retaining pin.

Mercury Tracker 25 gearcase installation

Step 7. Reinstall the starter and its two 10mm mounting bolts, and reconnect the wire leading to the starter solenoid.

Mercury outboard lower unit installation

Step 8. Reinstall the air intake cover and you’re done.

Mercury Tracker 25 gearcase reinstall

As previously noted, the steps to reinstall the gearcase onto a Mercury 25 are the same or similar for all outboard models. However, if you want to see this same job done on a higher horsepower engine, watch the video below to see how to remount the lower unit on a Mercury 200 outboard




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