SEI or OEM lower half unit

badrano

Petty Officer 1st Class
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Aug 7, 2018
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343
From another one of my posts, I ran over a small log and broke off a chunk of the anti-cavitation plate. Long story short, it's been recommended (several sources) to replace the lower half because of how the chunk of aluminum broke off. Welding a new piece in its place may not be strong enough since the breakage is on the upswing side of the prop. The insurance will cut a check that would basically pay for a mechanic to replace the lower half with OEM.

If I buy an SEI replacement and install it myself, I get to keep the remainder of the check. This may be a dumb question, since SEI is an aftermarket part, it is really as simple as pulling the old off and slapping the SEI unit on and hit the water? What is the easier way of doing this job...do I have to/should I pull the whole outdrive off?

I've read some posts of maybe having to adjust the shift linkage??

What's a good place to buy the SEI unit?

Or should I buy OEM?
 

muc

"Retired" Association of Marine Technicians...
Joined
Jul 7, 2004
Messages
2,144
It depends on how long you will keep the boat.
“You don’t get what you don’t pay for”
SEI isn’t a bad drive, but they are nowhere as good as OEM. They do have a long warranty, but it can take 3-6 weeks to get your drive back. MerCruiser is usually “in on Monday back before Friday”. Also if the SEI lower goes bad and ruins the upper, you pay for the upper. If that happens with a MerCruiser, they will pay for the upper.

You don’t need to pull the whole drive, you can just swap lowers. You do need to do a shift adjustment.

I’ve rebuilt 100’s of Alpha’s and never seen a anti-ventilation plate that couldn’t be repaired. Have you checked with a large propeller repair business?

If you do go with a SEI (I understand the lure of cheap) make sure you save the box and packaging to use to send it back for warranty.

If you like the boat and plan to keep it for many years. I recommend OEM.
 

Yegboats

Chief Petty Officer
Joined
Feb 20, 2016
Messages
518
If you like the boat and plan to keep it for many years. I recommend OEM. [/QUOTE]
I agree, especially since going with through insurance.
 

badrano

Petty Officer 1st Class
Joined
Aug 7, 2018
Messages
343
Also if the SEI lower goes bad and ruins the upper, you pay for the upper. If that happens with a MerCruiser, they will pay for the upper.
That is a very important piece of info to know!

I’ve rebuilt 100’s of Alpha’s and never seen a anti-ventilation plate that couldn’t be repaired. Have you checked with a large propeller repair business?
I haven't check with a prop shop, but since the insurance is paying for a replacement, the insurance guy did mention that if I just repair rather than replace, they wouldn't cover any subsequent damage. The lower half has other battle scars from the previous owner, so I guess at this point I might as well replace it.

I'm inclined to go OEM in the sense that this is not just an alternator, it's the transmission and the idea of having so called mismatched parts....maybe I'm just a little weird.

I just was looking other opinions as a sanity check...because I'm sure we all need it at this point.

Where is a good place to purchase the lower half? I've looked at Mercruiser Parts, but it seems they only offer the whole outdrive. I've also seen Crowley Marine. Can you get brand new Alpha I Gen II or are they OEM remanufactured?
 
Last edited:

Yegboats

Chief Petty Officer
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Feb 20, 2016
Messages
518
Any Merc dealer would be able to order in for you. If you pick up from them there should be no shipping charge. Unless you want it shipped to your door. Have them price match if necessary.
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muc

"Retired" Association of Marine Technicians...
Joined
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Messages
2,144
Yegboats do you know what Mercury’s parts warranty is? Volvo increased their one year parts warranty to two years if the customer purchased and had the dealer install the part. Has Mercury done anything like that?
 

Yegboats

Chief Petty Officer
Joined
Feb 20, 2016
Messages
518
muc That's a great incentive for volvo dealers. Merc is still just a standard one year limited warranty. There are times when they will extend a good will warranty if a failure occurs due to quality issues. I've seen them do it for coils, and cracked trim cylinders mostly. I have also seen Volvo cover the replacement design 2 trim cover for original owners 8 plus years out of warranty.
 
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