MerCruiser Sterndrive Lower Unit Removal & Disassembly

Knowing how remove the lower unit on a MerCruiser Bravo 2 sterndrive is essential for regular service and repairs.

Watch the video above and follow the steps below to remove the lower unit from a MerCruiser Bravo 2 diesel sterndrive. This walkthrough also covers how to disassemble the lower unit to replace leaking oil seals or worn bearings. 

Mercruiser Bravo 2 sterndrive removal breakdown

Tools - Mercruiser Bravo 2 Sterndrive Breakdown

MerCruiser Bravo 2 Lower Unit Teardown

Step 1. Bend back the tabs on the tab washer to release the prop nut, then remove the 36mm prop nut and the tab washer, the propeller and the thrust hub behind it.

MerCruiser Bravo 2 sterndrive lower unit breakdown

MerCruiser Bravo 2 sterndrive lower unit teardown

MerCruiser Bravo 2 sterndrive lower unit prop removal

MerCruiser Bravo 2 sterndrive lower unit prop removal

MerCruiser Bravo 2 sterndrive lower unit propeller removal

MerCruiser sterndrive lower unit prop removal

Step 2. Place a drain pan under the lower unit. Next, remove the oil drain/fill plug from the bottom of the lower unit and the vent plug from the upper right-side of the driveshaft housing, and let the gearcase lube drain out. 

MerCruiser Bravo 2 sterndrive lower unit oil

MerCruiser Bravo 2 sterndrive lower unit oil drain

Step 3. Support the lower unit to prevent it from falling, then remove the 16mm lower unit mounting bolts. There are three bolts on either side of the lower unit and one bolt within the trim tab anode housing.

MerCruiser Bravo 2 sterndrive lower unit mounting bolts

MerCruiser Bravo 2 lower unit mounting bolts

MerCruiser Bravo 2 sterndrive gearcase mounting bolts

MerCruiser Bravo 2 sterndrive gearcase breakdown

MerCruiser Bravo 2 sterndrive lower unit breakdown

Step 4. Remove the lower unit from the driveshaft housing.

MerCruiser Bravo 2 sterndrive lower unit removal

MerCruiser Bravo 2 lower unit removal

Watch the clip below to see the lower unit removal segment of our MerCruiser Bravo 2 lower unit video.

Step 5. Bend back the tabs on the tab washer to release the bearing carrier assembly’s retainer ring. Use a Mercury retainer ring tool to remove the retainer ring and tab washer.

MerCruiser Bravo 2 lower unit teardown

MerCruiser Bravo 2 lower unit break down

MerCruiser Bravo 2 lower unit disassembly

MerCruiser sterndrive lower unit disassembly

Step 6. Remove the bearing carrier assembly with a puller tool or slide hammer.

MerCruiser sterndrive lower unit teardown

MerCruiser sterndrive lower unit disassembly bearing carrier

MerCruiser sterndrive lower unit teardown bearing carrier

MerCruiser sterndrive lower unit breakdown bearing carrier

MerCruiser lower unit breakdown bearing carrier

Step 7. Pull the prop shaft out from the gearcase.

MerCruiser sterndrive lower unit breakdown prop shaft removal

Step 8. Hold the drive shaft with a Mercury driveshaft adapter tool connected to a 32mm socket and remove the 14mm pinion gear nut from within the gearcase.

MerCruiser Bravo 2 lower unit gear removal

Step 9. Remove the clamp plate from the top of the lower unit.

MerCruiser Bravo 2 gearcase teardown

Step 10. Remove the O-ring, spacer, shims and tab washer from the lower unit, then lift the driveshaft out from the lower unit.

MerCruiser Bravo 2 gearcase breakdown

MerCruiser Bravo 2 gearcase breakdown O-ring removal

MerCruiser Bravo 2 gearcase disassembly

MerCruiser Bravo 2 gearcase disassembly driveshaft removal

Step 11. Remove the O-ring, thrust ring and load ring from the gearcase. 

MerCruiser Bravo 2 engine gearcase disassembly

MerCruiser Bravo 2 engine gearcase teardown

MerCruiser Bravo 2 engine gearcase disassembly

Step 12. Remove the pinion gear from the gearcase.

MerCruiser Bravo 2 engine lower unit disassembly

Step 13. Use a slide hammer/puller to remove the driveshaft bearing race from the top of the lower unit and the prop shaft bearing race from within the gearcase.

MerCruiser Bravo 2 engine lower unit teardown

MerCruiser Bravo 2 engine lower unit breakdown

Step 14. Remove the shims beneath the driveshaft bearing race and the prop shaft bearing race and you’re done.

MerCruiser Bravo 2 sterndrive engine lower unit breakdown

MerCruiser Bravo 2 sterndrive engine lower unit teardown

Watch the clip below to see the lower unit disassembly segment of our MerCruiser Bravo 2 lower unit video.

 

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