Lower Unit Replacement

[boater2018]

I have a 2001 Sundeck 210 with a 5.0, Alpha 1 Gen 2 Outdrive 1.62 gear ratio. I had my lower unit serviced last year and the mechanic that serviced it said the lower unit housing had some pitting and next time I have it serviced, I may want to consider replacing the lower unit. My boat runs great with no sign of leakage in the lower unit, but I am considering replacing it next spring as I try to have the lower unit serviced every other season. I am considering 3 options and would be open to recommendations based on your experience:

Option 1: Replace it with an SEI lower unit. I hate to spend the big bucks a new Merc runs compared to an SEI, if the SEI units are reliable. (My brother replaced his 210 BR lower with one of these and it worked out great for him, but he only had it on for 1 season and then bought a new Cobalt, so idk how it would hold up long term)

Option 2: Have my unit rebuilt with a new housing or find a used unit with a good housing?

Option 3: Replace with a good used or new OEM unit

Any input it appreciated!

 

[BillK2632]

On an older boat with an Alpha, I would go with the SEI if I were replacing it. But I also would be inclined to run the existing drive until you start having actual problems - without seeing it, it's hard to know how bad the pitting is. I seen some in pretty bad shape cosmetically, but still perfectly functional.

 

[boater2018]

On an older boat with an Alpha, I would go with the SEI if I were replacing it. But I also would be inclined to run the existing drive until you start having actual problems - without seeing it, it's hard to know how bad the pitting is. I seen some in pretty bad shape cosmetically, but still perfectly functional.

I have thought about that as well. The mechanic said he put some slime or something on it and got it sealed off good. I was thinking any mechanic should be able to scrape some of that off and do it again, if needed. I haven't noticed any film in the water from the outdrive and I changed the fluid in it this spring and it looked great, so I don't think there has been any water intrusion.

 

[Nater Potater]

My '92 outdrives are totally trashed from pitting, to the point where they'll require destructive measures when anything internal needs to be done. However, I replaced the water pumps, and am going to run them until they die. As long as the oil doesn't show signs of leaking out or water getting in, rock and roll.
Once that happens, I'll probably go looking for usable used housings and salvage their internals, as the guts seem to be fine. Just keep the water out of the oil.

 

[Strecker25]

I’d run it until you have problems unless you’re regularly a long way from home. If not, you could get a lower replaced in 2 hours including the time to put the boat on the trailer.

i blew up two SEI’s but it was on our 290 and that was a big heavy boat at the edge of what alphas should be on, IMO

 

[Pirate Lady]

I am with strecker. I would never get an SEI. Just me. Chinese parts, dont last long after warranty runs out. But then im the guy that pays $60 for original brake pads from dealer, not $20 from Autozone because they don’t produce black dust or tear up rotors.

 

[Mark.60]

I used the SEI on a 25 sundancer for 5 years and two on a 30 sundancer with no problems. How much of the mercruiser drive is built in the USA ?

 

[JHornsby3]

Just get a couple things of Hubba Bubba. Smear it on over the pitting and paint er up.

I would think a cleaning and good coat of Duracoat epoxy primer would seal and protect the case. Big thing would be to seal the surface and stop the corrosion then just run em.

 

[northern]

I had twin V6 with OMC outdrives. One got a hole in it due to pitting. Mechanic repaired it with steel epoxy and it lasted many years. He said he had done a few that way and all worked.

 

[Lazy Daze]

The bearing carrier is typically the area that takes out drives. Pull the prop and check that area out.

 

[Arminius]

I'd have a specialist in corrosion/galvanic action take a look at reducing future deterioration. Check/replace zincs at a minimum.

 

[Little Ducky]

"Some pitting" how sweet.

Both of mine look like a shark has been gnawing on them but they have been serviced, painted, sealed and still trouble free. I'm going to be using them until they fall off the boat before replacing.

Nice thing about a trailered boat you can keep an eye on the situation. I'll probably just see an oil slick at some point around my boat at the slip when they give up the ghost.

 

[Nater Potater]

The bearing carrier is typically the area that takes out drives. Pull the prop and check that area out.

And that's exactly where mine went really bad. Like @Lazy Daze mentioned, pull the prop and check the carrier. Mine are scary-corroded, but still oil tight. As mentioned earlier, if you're not leaking oil out or water in, you should be good to go. Just keep a vigilant eye on it.

 

[JHornsby3]

Nator Tator and I did things backwards. He came here to the coastal area to get his 300DA. And I wanted something better so I went to Idaho to get my 300DA. So with that, my bearing carriers are like mint. I'm sure his look like Alumazinc piranha fish have been living in his.

 

[Daniel1980]

I would replace the lower with a used Mercury lower....swapping it out for one in good shape, but still oem, while not aftermarket junk.

There seems to be a lot of teaser aftermarket parts out there made in evil China. They can kiss my ass, especially after making the world sick.

 

[JHornsby3]

Might check to see where your current drive was made. That and the parts inside. Or the parts in the vehicle you drive. I have found VW/Audi parts with Hecho en china on them

 

[Arminius]

With Chinese components, many have concerns regarding metallurgy, precision measurements and longevity. The same tie rod end went out twice on my MB so I guess I should have done business with Stuttgart. A used lower case sounds good.

 

[Nater Potater]

Augh! Not more covid/political noise! We're talking outdrive replacement. And yes, my outdrives are trash, but they still work fine. Just keep an eye on your oil for water and level.