Coupler gone

Strecker25

Strecker25

Well-Known Member
SILVER Sponsor
Nov 20, 2014
4,931
Rochester, NY
Boat Info
2002 410DA
Engines
Caterpillar 350HP 3126
More of a rant than anything because I'm so aggravated but lost our port coupler today while idling out of our marina tho get gas for a 3 day trip we had planned. No dramatic failure, just a clunk and a stall. Started back up no problem but temp was slowly rising and no thrust. Confirmed at the dock I could spin the prop in gear with a wrench on it so the coupler has completely let go. Not that inboards don't have their issues but I'm really sick of the i/o nonsense.
 
Beginning of the season when I reinstalled the drive me usually every 25 hours or so. We've only put 20 hours on this season because the water level in the lake is so high so I haven't greased it a second time.
 
May want to confirm this is your issue. Clunk and a stall sound more like your drive let go. Couplers can last a very long time if greased and aligned
 
We'll confirm it for sure before any work is done, prop still locks on the dogs in forward and reverse but maybe the upper blew up?
 
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Strecker25 said:
We'll confirm it for sure before any work is done, prop still locks on the docks in forward and reverse but maybe the upper blew up?
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I had a gear strip in the upper unit on an alpha drive in a previous boat.....simple to check...just remove the top cap of the upper drive and look at the gears......

cliff
 
Cliffs comment got me thinking. Although it's coming out next week I'd like to troubleshoot. Our bilge is brutal for access and I can barely see the driveshaft and coupler. If the splines on the yoke or coupler are stripped, would the part of the coupler with the zerk still spin? How about if the rubber part let go, would it not spin then?

Im going to try and put a mark on the driveshaft but it's really hard to reach or see
 
The part you see will spin with the motor , the rubber hub and internal sleeve you wont see.
How was the engine alignment when you installed the drive? Any drive service performed that may have let to losing the drive oil?
 
Bt Doctur said:
The part you see will spin with the motor , the rubber hub and internal sleeve you wont see.
How was the engine alignment when you installed the drive? Any drive service performed that may have let to losing the drive oil?
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Thanks BT. Alignment was good, checked yearly on both sides with an alignment bar per the manual and no issues there. No drive service since reinstalling the drives in the spring (lube change, impeller, new bellhousing gaskets, greased up yoke splines, reinstalled)

I had a very slight drop in drive lube in the reservoir after a 3 our run (1-2oz) two weeks ago and had to top it off. Put 3 more hours on it since the top off with no loss of lube, so I was thinking still air in the drive from the change.


Boat has been pulled and mechanic is getting into it now, I'll report back what they find.
 
Yeah, now we are. In today's lesson of not jumping to conclusions, we blew ANOTHER SEI Lower unit. Last time it threw a pinion gear, this time it locked up and sheared the vertical shaft in two. It's all a warranty claim, but we will now miss 2 weekends on the boat :smt013

this drive has just over 100 hours on it and has been maintained perfectly. I've lost all confidence in SEI

Here's whats left of the shaft. Notice the splines are twisted. There is no impact damage anywhere on the housing and the prop is perfect. It's also an aluminum prop, so it would be mangled if we hit something.

Edit: Had to renew my site support, I'll upload when it kicks back in
 
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i have a friend who wrecked the vertical shaft on an alpha connected to a 5.7 mercruiser and he nearly blew the engine because he did not realized the impeller in this case will also not spin anymore . i believe an alpha will not last long attached to a 5.7 , especially when you 'gun' the engine

but glad you have warranty !
 
aerobat77 said:
i have a friend who wrecked the vertical shaft on an alpha connected to a 5.7 mercruiser and he nearly blew the engine because he did not realized the impeller in this case will also not spin anymore . i believe an alpha will not last long attached to a 5.7 , especially when you 'gun' the engine

but glad you have warranty !
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I tend to agree. As much as I love our boat, the 350's on the alpha make me a bit uneasy. I roll into (and off) the throttle, never go WOT unless I'm testing props, and generally take it very easy on our boat but at the end of the day it weighs 11,000+ lbs and seems like a lot of boat for those little alpha shafts.
 
It's doable, but a lot of work and money. Searay went to bravo3's on the 290 in 2000, a much better package in my opinion. It would be new transom assemblies which means both motors out, new drives, etc. We're in the process of boat shopping anyways so it will likely be listed sometime in the next month or so. There's plenty of these boats out there (and others) with this power combo so it has to work in some capacity, maybe we're just unlucky. Someone will get a nice deal since both lowers will have less than 30 hours on them when we sell.

v drives are in my future.:wink:
 
While loosing a couple weekends on a short season stinks I'd venture that having to get a new lower unit under warranty is still better than a blown engine coupler.

Mine gave out last year. Idling along in the mooring field, then no power forward or back. The engine had to come out to replace the coupler. We lost several weeks of boating plus a couple grand for the work.
 
Agreed. Not a fan of losing time, but we've spent a ton of time on the boat this year already and a week or two to do other things isn't all that bad. By other things I mean plan day trips to places with boats we're interested in upgrading to, lol.
 
I really enjoyed our 290 but having a bilge I fit in and V drives is pretty nice now.
 
magstang1 said:
I really enjoyed our 290 but having a bilge I fit in and V drives is pretty nice now.
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The 340s with 454's don't offer much in the way of extra room in the bilge but I sure want those inboards after these alpha issues we've had
 
Update: New lower is installed. Lost two weeks total and god knows how much money for the whole job. $350 in total shipping billed to me, and now I'm stuck with a 10 hour break-in period. Five of which I cannot get on plane because they want the revs kept below 3400.

The worst part of the whole situation is the lost confidence in the boat. We really like to travel all over lake ontario and with two failures I'm very nervous about it happening again. You can see the twisted splines and where it sheared. SEI said it locked up from a failed clutch assembly

IMG_2751.jpg
 
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