I think my outdrive blew..

[BMK10]

Hey guys, new to the forum and new to the boating world...
Just bought an 87' starcraft and I've been boating a lot this summer. Motor runs great and I was just bragging to my buddy the other day about how awesome it runs (guess I jinxed myself.)
I was on the water the other day and everything was running fine, then randomly I tried to move and the prop would not engage, fwd or rev. I checked my shift cables and they appear to be fine, I just had it adjusted this spring. So I pulled the lower unit and I think my problem is somewhere in there.
Really just looking for some opinions on how to go about replacing this. Is a rebuild worth it? I've built several transmissions and axles on cars so setting up gears and what not is not a huge deal, but like I said boats are new to me and I'm wondering if it would be cheaper to just buy a new or used lower unit.
I attached a video below, the unit is engaged and you can hear the awful sound its making.
Also not sure if this makes a difference but the boat usually never sits in water and this past week I left it at a buddy's place in the water for about 6 days. I'm wondering if maybe the seals were slowly going and allowed water to get in since it was sitting for so long?
Figured I should post on here before I go tearing the unit apart. Also its a 3.0L mercruiser with an alpha one.
Thanks
Brad

https://www.youtube.com/watch?v=bIuP...ature=youtu.be

 

[Bondo]

Ayuh,.... Welcome Aboard,..... Did ya drain the oil,..??

Any metal in it,..??

The sound yer hearin' is the rubber impeller turnin',....

 

[tpenfield]

Yes, you'll wear your self out jumping to conclusion. start with the basics and work your way up.

 

[BMK10]

Ayuh,.... Welcome Aboard,..... Did ya drain the oil,..??

Any metal in it,..??

The sound yer hearin' is the rubber impeller turnin',....

Just drained it. No metal that I can see. I changed it this spring so the oil is actually quite clean.

 

[BMK10]

Yes, you'll wear your self out jumping to conclusion. start with the basics and work your way up.

I completely agree. I've jumped to conclusion too many times with my cars and caused many unnecessary headaches hahaha.

 

[Bondo]

Just drained it. No metal that I can see. I changed it this spring so the oil is actually quite clean.

Ok,.... Pull the prop, 'n check it's hub,....

Split the lower from the upper, 'n see if the top of the vertical shaft snapped off,...

Look in through the gimbel bearin', 'n see what the coupler, 'n it's splines look like,...
Any metal debris on the splines by yer left hand,..?? if it's just Greasy, that's a Plus,...

 

[BMK10]

I split the case, top vertical shaft seems to be fine. Coupler looks okay from what I can see, however I am not positive as to what I'm exactly looking for since its so far in but there wasn't any metal debris on the output shaft. I pulled the prop as well and I think its okay. I googled a bad prop since I've never seen one so I think mine is fine because there is no slop and doesn't seem to be spun.
Also I pulled the top gear cover on the upper housing and the gears seem to be fine and are meshing smoothly.
I did notice however when I split the case there was a little oil that leaked out (I had already drained it before disassembly) and there was a small amount of water mixed in with it....

 

[nola mike]

Sometimes there'll be water on the drive itself that mixes with the little bit of oil. Significant water would have shown right when you pulled the plug. Just out of curiosity, did you actually verify that the drive itself wasn't going into gear by shifting directly at the drive?

 

[BMK10]

Sometimes there'll be water on the drive itself that mixes with the little bit of oil. Significant water would have shown right when you pulled the plug. Just out of curiosity, did you actually verify that the drive itself wasn't going into gear by shifting directly at the drive?

I checked to see if the unit would engage while it was attached to the boat and running using the shifter. Obviously got nothing, I couldn't even hear the dogs (I believe they're called) trying to engage, just the engine revving. Then once I pulled the lower unit you can see in the video I was turning it manually by hand and it appears to engaged/ spinning. I was able to get the prob to disengage/engage by hand so I'm not entirely sure what's going on.
Hope that answers your question.

 

[nola mike]

Yeah, that's what I was wondering, if this could be just a cable/adjustment issue. A spun prop could cause those symptoms, as could a coupler (knowing if it was engaging while mounted could help with that). If you look at the coupler and it looks OK, I'd be tempted to put the drive back on the boat, take the lower shifter cable off, and see what happens when you shift it by hand. Clean oil, spinning input shaft, clean upper gearset makes me think that the drive is OK. Actually, a coupler shouldn't cause those symptoms, nor would a spun prop--the drive would still clunk into gear, you just wouldn't move.

 

[Rick Stephens]

Could be something as simple as a missing washer on the lower shift shaft.

 

[harleyman1975]

I'm thinking a broken lower cable.

 

[BMK10]

Yeah, that's what I was wondering, if this could be just a cable/adjustment issue. A spun prop could cause those symptoms, as could a coupler (knowing if it was engaging while mounted could help with that). If you look at the coupler and it looks OK, I'd be tempted to put the drive back on the boat, take the lower shifter cable off, and see what happens when you shift it by hand. Clean oil, spinning input shaft, clean upper gearset makes me think that the drive is OK. Actually, a coupler shouldn't cause those symptoms, nor would a spun prop--the drive would still clunk into gear, you just wouldn't move.

To be honest I'm not sure how to tell if the coupler is bad. All I did was shine a light and visually check, I can see the gimbal bearing and then another bearing further in (which I assume is the coupler) there is grease inside and nothing seems to be out of the ordinary. Also the outdrive shaft as I stated before seems clean.
And yes I agree about the spun prop too because the engine is just revving, no signs at all of it even trying to engage. Before I pulled the lower unit off the boat I slightly removed it to exposed the lower shift cable and while my brother was shifting the cables I was able to verify that it WAS shifting back and forth so I'm assuming the issue isn't in the cable, correct?
Also I'm not sure if this could be relevant to my problem but the engine seems to shake quite a bit at idle. I checked the motor mounts which appear okay however where the mounts bolt onto (stringers i think?) there is a small crack allowing for some slop. I can wiggle the engine only a small amount by hand but I'm assuming that can't be good.
Maybe I'll re-assemble like you said and try to manually engage the lower unit and see what happens...

 

[BMK10]

Could be something as simple as a missing washer on the lower shift shaft.

Just checked, not the problem. That woulda be nice though! haha

 

[nola mike]

To be honest I'm not sure how to tell if the coupler is bad.

Don't think it is, but with the drive on, you should be able to see the shaft coming from the coupler from the inside of the boat. If the coupler is bad enough to not engage the gear at all, the shaft won't be spinning with the motor running.

Before I pulled the lower unit off the boat I slightly removed it to exposed the lower shift cable and while my brother was shifting the cables I was able to verify that it WAS shifting back and forth so I'm assuming the issue isn't in the cable, correct?

Not sure what you're saying here, but with the drive all the way off it's easy enough to see if the cable is snapped. While you're at it, make sure that the roller on the shift shaft is engaging correctly and nothing is bent. With the drive fully on, you can see if moving the shift cable turns the shift shoe on the drive

I checked the motor mounts which appear okay however where the mounts bolt onto (stringers i think?) there is a small crack allowing for some slop. I can wiggle the engine only a small amount by hand but I'm assuming that can't be good.
Maybe I'll re-assemble like you said and try to manually engage the lower unit and see what happens...

That's worrisome, though probably unrelated. The stringers are wood encased in fiberglass. Your mounting bolts go through the glass and into the wood. If it's loose (and can't be tightened), that's concerning for rotted stringers (it would be rotted wood, not a crack in the glass that would allow for the slop). You can check by drilling into the stringer with a small bit, and filling in the hole with 5200 or epoxy. You should get clean shavings back. Mush = rot.

 

[BMK10]

Don't think it is, but with the drive on, you should be able to see the shaft coming from the coupler from the inside of the boat. If the coupler is bad enough to not engage the gear at all, the shaft won't be spinning with the motor running.

I took another video, figured it'd be easier than explaining. Engine is first in neutral then engaged to forward. It looks like the shaft isn't spinning at all. When I lost power on the water the other day it made a nasty sound when trying to engage for a couple seconds and then it was gone. Now the engine just revs as you can see. Also there are a bunch of metal shavings on the left side of the engine in the beginning, kind of hard to see but I just noticed them.
https://www.youtube.com/watch?v=sQGa...ature=youtu.be

Not sure what you're saying here, but with the drive all the way off it's easy enough to see if the cable is snapped. While you're at it, make sure that the roller on the shift shaft is engaging correctly and nothing is bent. With the drive fully on, you can see if moving the shift cable turns the shift shoe on the drive

Sorry just re-read that post.. I installed the unit and checked the shift shoe/cable and it is clearly shifting through fwd-neutral-reverse. I just replaced the lower shift cable last summer so everything is basically new.

 

[Bondo]

Ayuh,.... The coupler is spinnin', but the output shaft is Not turnin',...
It's visible at 'bout 10 seconds, 'n again at the end of the video,...

The coupler is blown,....

 

[nola mike]

Ayuh,.... The coupler is spinnin', but the output shaft is Not turnin',...
It's visible at 'bout 10 seconds, 'n again at the end of the video,...

The coupler is blown,....

Yup, and I'd double down on what I said about the stringers. If the engine mount was loose, your alignment was probably off,= blown coupler. You might want to check the stringers before you pull the engine to see if it's worth repairing...

 

[BMK10]

Damn I had a feeling, that sucks. Well hey this will probably be cheaper than replacing the lower unit! :lol:
What exactly is involved in this? Remove lower unit, pull the engine, and unbolt the coupler?
I'm more concerned with why it blew. I replaced all the bellows last year and never did an alignment check (noobie), I'm wondering if that was the cause to my problem. Also maybe I will drill into the stringers and take a peak like nola mike mentioned.
Thanks for the help guys. Glad I know what it is at least.

Is this what I'm looking for, or something in this nature?
http://www.ebay.com/itm/Sierra-18-2...erndrive-Engine-Coupler-76850A2-/291528264760

 

[BMK10]

Yup, and I'd double down on what I said about the stringers. If the engine mount was loose, your alignment was probably off,= blown coupler. You might want to check the stringers before you pull the engine to see if it's worth repairing...

Yea I'm going to. Hopefully they're not too bad.