Outboard Lower Unit & Gearcase Repair
Milky gear oil, a leaking seal, or a lower unit that won't shift? We pressure test, reseal, and repair lower units and replace props and prop shafts.
Ethan, the owner and mechanic, answers the phone · Open 7 days a week
- Same / next day availability
- On-site & marina service
Outboard Lower Unit Repair
A lower unit can cost thousands to replace, and most failures start with a cheap seal or a skipped oil change. We service, test, and repair lower units at your dock or during a haul-out.
Trusted by boat owners across South Florida
Read our Google reviewsNo call center. No front desk.
When You Call, the Owner Picks Up
Every call goes straight to Ethan, the owner of EG Marine Services and the mechanic who does the work. There’s no receptionist taking a message and no waiting on a callback from someone who’s never seen your boat.
Tell him what’s going on: the alarm on the display, the noise at idle, the engine that won’t turn over. Ethan knows Yamaha, Suzuki, Mercury, and the rest of what runs in South Florida inside and out, so you’ll usually get a straight answer on the first call, whether that’s something you can check yourself or a visit to your dock.
- Straight answers, not a script
- Diagnostic questions answered on the phone
- Honest advice, even when the fix is simple
- The person you talk to is the one who shows up
Ethan
Marine mechanic
Describe what the boat is doing and get a real answer from the mechanic, not a message taker.
Call Ethan: 786-351-5363Open 7 days a week
Lower unit leaking, noisy, or milky? Call Ethan before your next run.
Call 786-351-5363Signs Your Lower Unit Needs Repair
- Milky or metallic gear oil
- Oil leaking around the prop shaft
- Clunking or grinding when shifting
- Won't go into gear
- Vibration after hitting something
- Missing or loose prop nut
Real Lower Unit and Gearcase Jobs
Zero oil inside
A Yamaha 250 had a blown aftermarket lower unit with zero oil inside.
Lost prop
A lost prop led to a blown gearcase. "It's cheaper to install new prop nuts than a $10,000 gear case."
Reseals and prop shafts
Resealed lower units and new prop shafts on Mercury, Suzuki, and Yamaha outboards.
Locked-up lower unit
A locked-up lower unit shut the motor down. It was replaced to get the boat running again.
Our Lower Unit Repair Process
- 01
Drain and Inspect
We drain the gear oil and check it for water and metal.
- 02
Pressure Test
A pressure and vacuum test finds leaking seals.
- 03
Repair
We replace seals, shafts, or the lower unit as needed.
- 04
Refill and Test
We refill with the correct oil and test shifting.
From the Job Log
Pressure test on an outboard lower unit gearcase 
Outboard lower unit gear oil drained and checked
Get Your Lower Unit Checked
If you see milky gear oil, stop running it and call.
Call Ethan directly786-351-5363Open 7 days a week · No call center or front desk, you talk to the person doing the work
- Gear oil service
- Pressure and vacuum tests
- Seal and prop shaft replacement
- Lower unit replacement
Prefer a free quote?
Leave your number and we’ll call you back.
Outboard Lower Unit & Gearcase Repair FAQs
What does milky lower unit oil mean?
Water is getting past a seal and mixing with the gear oil. Caught early, a reseal usually fixes it. Ignored, it destroys the gears and bearings.
How often should I change lower unit oil?
Every 100 hours or once a year as part of regular service.
Why did my lower unit blow up?
Usually low or no oil, water intrusion, or a hard hit. We've seen an aftermarket lower unit fail with zero oil inside, and a lost prop nut lead to a blown gearcase.
Areas We Serve
Our mobile marine mechanics travel to marinas, private docks, and waterfront homes from Boca Raton to Islamorada. Nearby but not listed? Reach out to confirm availability in your area.