blew my alpha one, what did i break?

[500dollar744ti]

well, i know you can't tell me what broke but you can guess. 1990 350 magnum alpha 1, gen 1, 270hp, 14.75 x 20p solas titan SS prop. i think i was overpropped for the load but my 17p spun a hub the day before.

was out in the ocean on a nice day, pulling a tuber right along the coast about 200 yards away from the beach. boat loaded with 6 people at about 20mph. just running along nicely, i'm watching in front, my spotter right next to me watching the tuber.

lost all forward movement, engine revved and i yanked it back to idle. i shut the motor down and made some inspections, didn't see anything visually amiss, so started it back up and found i had no forward or reverse.

i let it idle for a bit to see if the temp was going up and it was so i shut it down. i jumped in the water with it in forward gear and i was able to turn the prop both ways.

i haven't had this boat long and i didn't get a boatUS membership yet for towing, be sure i'll have one before i go out again. was very lucky to be able to call up a neighbor and have him come out to me and tow me to the launch so i could pull the boat out.

i pulled the drive off today, found the problem to be between the input shaft and the prop shaft. thank goodness it's not an engine coupler.

with the outdrive off, i can put it in gear manually and lock the prop but it still spins independently of the upper input shaft.

any guesses where it broke? my prediction is the long shaft that sticks out of the lower unit, it looked like a pretty wimpy thing to me last time i had it apart.

if it is the lower unit, are there any options for me as like an upgrade with something beefy-er? i'm a car guy and if something breaks on my race car i generally try to not just fix it but also make it better so it won't happen again.

i can't swap a bravo without pulling the motor, correct?

i'm going to make myself a nice meal and then after dinner i might go split the outdrive to find the broken stuff.

iboats is awesome by the way!

 

[Bondo]

Re: blew my alpha one, what did i break?

any guesses where it broke? my prediction is the long shaft that sticks out of the lower unit, it looked like a pretty wimpy thing to me last time i had it apart.

if it is the lower unit, are there any options for me as like an upgrade with

Ayuh,.... I'm guessin', Yer Right,.... right at the o-ring groove....

The SEI replacements are hard to beat,....

 

[achris]

Re: blew my alpha one, what did i break?

If you didn't hit anything in the water, then my guess would be the splines in the bottom of the upper driven gear have rusted out and you've spun them... The only fix for that is to replace the upper driven gear, which is also means replacing the drive gear (they're a matched set). By the time you get the tools and parts, it will be cheaper to buy a brand new upper from SEI... About $700.

All that said, you need to split the drive to verify what's popped.

Chris........

 

[thumpar]

Re: blew my alpha one, what did i break?

Since it was over heating it has to be above the impeller. I would split the drive. It should be easy to figure out from there.

 

[ktbarrentine]

Re: blew my alpha one, what did i break?

Since we're plugging away with guesses, my money is on stripped upper gears. Can't wait to see the verdict! Pull the upper cap to take a quick look-see.

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

didn't get a chance to mess with it any more yesterday, i'm going to find out what broke today when i get home from work.

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

so there was water in the gear case, that certainly accelerated the failure. how can water enter the gear case anyway? i changed the gear oil out when i did the water pump and it was clean, checked the new oil a while ago and it was still clean. how does the lower gear case seal at the prop? i think i bumped the prop on the big log that stops the trailer from going all the way in when i launched the boat, is that enough to breach whatever seals it?

also, why is so little of the lower unit shaft seated in the upper gear? is that because someone set lash incorrectly when they did gears or something on it? i just got this boat, history unknown, trying to do my best to catch up on maintenance.

i also replaced all the bellows but i'm still getting some goop at the bottom of the drive bellows when i take the drive off. it's not like it's full of water like before when the seals were leaking but there's some stuff that runs out, is that normal? is it possible to keep the thing bone dry or is that just not going to happen?

there may also be water getting into my shift cable cavity, i put a new welch plug in it because that was missing and obviously necessary but i still think some water is getting in. what seals the drive side of the shift cable? i know the gimbal side has a bellows but it's like a cone and doesn't reach all the way to the drive.

last question, i'm going to replace my lower unit, i've been suspicious of a slightly bent prop shaft even though i haven't got the tools to prove it. i am thinking the water is getting into the gear case at the lower unit. can i replace the gear set in the upper unit or do i need to look for another upper unit because there was water entry?

 

[Bondo]

Re: blew my alpha one, what did i break?

so there was water in the gear case, that certainly accelerated the failure. how can water enter the gear case anyway? i changed the gear oil out when i did the water pump and it was clean, checked the new oil a while ago and it was still clean. how does the lower gear case seal at the prop? i think i bumped the prop on the big log that stops the trailer from going all the way in when i launched the boat, is that enough to breach whatever seals it?

also, why is so little of the lower unit shaft seated in the upper gear? is that because someone set lash incorrectly when they did gears or something on it? i just got this boat, history unknown, trying to do my best to catch up on maintenance.

i also replaced all the bellows but i'm still getting some goop at the bottom of the drive bellows when i take the drive off. it's not like it's full of water like before when the seals were leaking but there's some stuff that runs out, is that normal? is it possible to keep the thing bone dry or is that just not going to happen?

there may also be water getting into my shift cable cavity, i put a new welch plug in it because that was missing and obviously necessary but i still think some water is getting in. what seals the drive side of the shift cable? i know the gimbal side has a bellows but it's like a cone and doesn't reach all the way to the drive.

last question, i'm going to replace my lower unit, i've been suspicious of a slightly bent prop shaft even though i haven't got the tools to prove it. i am thinking the water is getting into the gear case at the lower unit. can i replace the gear set in the upper unit or do i need to look for another upper unit because there was water entry?

View attachment 167779View attachment 167780

Ayuh,... You need a new Outdrive,.... All of it....

 

[Fishermark]

Re: blew my alpha one, what did i break?

^^^ Yep, time for a new SEI drive.

It may not make you feel any better, but the same exact thing happened to me a few years ago:

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

can't replace the lower and rebuild the upper?

 

[Bondo]

Re: blew my alpha one, what did i break?

can't replace the lower and rebuild the upper?

Ayuh,.... Sure,... Do anything ya want,... rebuildin' the upper costs 'bout what a New SEI costs...

 

[oldjeep]

Re: blew my alpha one, what did i break?

can't replace the lower and rebuild the upper?

It'll be cheaper to just replace both than to replace the lower and rebuild the upper. $1300 for the upper and lower.

http://www.sterndrive.cc/mm5/merchant.mvc?Screen=CTGY&Category_Code=MercruiserAlphaSterndrive

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

these SEI units, where are they made, good reputation? i'm very weary of aftermarket stuff, most cases i'd rather have lightly used OEM than new aftermarket when it comes to cars but i don't know boats that well yet.

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

It'll be cheaper to just replace both than to replace the lower and rebuild the upper. $1300 for the upper and lower.

http://www.sterndrive.cc/mm5/merchant.mvc?Screen=CTGY&Category_Code=MercruiserAlphaSterndrive

it says the unit has the new-style yoke, does that mean i have to change anything on my current setup to run it?

 

[ktbarrentine]

Re: blew my alpha one, what did i break?

Ahhh...tis but a flesh wound! :facepalm: JK! Seriously though, do you have an exploded view to help show you what broke and where....You should finish the disassembly to see the mechanism of the break(s) and to see just how much vert shaft spline does actually enter the driven gear splined area. The SEIs have a great reputation! I'm sure others will chime in. I wouldn't even trust "lightly used" replacement OEM drives.... Trust factor. Just need to make sure it has the same length yoke shaft (coupler shaft). best of luck!

 

[Fishermark]

Re: blew my alpha one, what did i break?

these SEI units, where are they made, good reputation?

Good? In the words of Tony the Tiger: "They're Gr-r-r-eat!" Not only are they a quality product - but as good as the actual product is - the reputation and customer service of the company itself is outstanding. I have installed a couple of these units, and one did have to have work done on it under warranty. They completely rebuilt the unit and shipped it back to me with free shipping. (I dropped it off to their shop locally). I can't say enough good about this company, and no, I don't work there or get any kick backs.

 

[akorcovelos]

Re: blew my alpha one, what did i break?

you really turned the prop by hand with the engine running and in gear? you must hate your fingers.

 

[500dollar744ti]

Re: blew my alpha one, what did i break?

you really turned the prop by hand with the engine running and in gear? you must hate your fingers.

no, read again...

i let it idle for a bit to see if the temp was going up and it was so i shut it down. i jumped in the water with it in forward gear and i was able to turn the prop both ways.

anyway...

as great of a deal as those SEI units sound with a warranty and all that, it's just not in the works for me financially.

i have to leave some money for a starter and a couple of other things. my starter took a dump on me and i had a spare but it was a new-style GM truck starter. i only put it on because i had nothing else at the time. i want to get a marine starter back in there before using the boat again. someone told me the '99 GM starter is already sealed from sparking, both auto and marine but i can't be sure.

i ended up buying this, i'll go through it when i get it and do the impeller but it's within my budget.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=261095159186

 

[akorcovelos]

Re: blew my alpha one, what did i break?

sorry bout that. good luck with the new unit, looks like a good deal.

 

[ktbarrentine]

Re: blew my alpha one, what did i break?

+1 on good luck with the ebay unit. let us know how that works out for you. Looks like its seen a bit of saltwater service (located in FL). Didn't see the ratio in the listing, but based on what it came out of, it sounds right. Did you check? What ratio are you replacing?