I think I blew my drive

[CDMA]

So I have been so busy driving my little yellow pocket rocket to post. I have about 20 hours on the new Alpha swap and it has been great. I have been having a great time....then last Friday it happened. I was driving in the LI sound and admittedly pushing the boat pretty hard. In a turn, which I neglected to tuck the drive in for, the prop ventilated and the revs quickly spiked to 5400-5600 rpm. Just for a second and I yanked the throttle back but however this was not before a loud ping and what sounded like some sort of slap. Put it in neutral and popped the hatch. Engine running fine, good oil pressure good water temp. Smooth and everything. So revved it up and sounded ok. Put it in gear and idled away no problem. Went to get up on plane and there was some pretty nasty noises....like horrible. Tried again....same thing. So we got it to the beach at my school and were able to get it up and out. Checked the engine oild and it looked fine. Then I drained the oil in the drive and expected to see a lot of metal shavings. There were a few but nothing more than I expected after dealing with dog style cluthes my whole life. So I still think the Alpha is done though. I need your guys help. Does this sound like the upper case or the lower??? What can I do to figure this out. Should I rebuild it myself or what. I really am in a bind. I have been in school now for 4 months with little to no income and I am basically poor. I worked all winter on this thing and now I want to play. Any thoughts or ideas would be really appreciated... http://www.donzi.net/ubb/frown.gif http://www.donzi.net/ubb/frown.gif http://www.donzi.net/ubb/frown.gif

Thanks guys


Chris


[This message has been edited by CDMA (edited 06-10-2001).]

[AVickers]

Here's a guess.

The downshaft (between the upper and lower gearboxes) is supposed to break when things get tough. This so that nothing else gives out when you hit something underwater. The only other thing I can think of is the input shaft splines on the pinion in the lower unit. That appears to be the weakest link in the system... Plus, a failure here would probably allow low-speed driving, but would crap out as the speed (and load) got higher.

I've never heard of either failing when the prop comes out and then gets a bit again, but maybe.......

Not sure what HP you're running, but I've heard that Alphas are limited to the 300 to 350 range... Anything above this and you should be using a Bravo, King Cobra or Volvo.

Keep us posted.

Oh, and I'd suggest you do the work yourself. Good learning experience... I resealed my unit last month and other than a problem with a couple of special tools, it was cake. A local guy applied his tools when I needed them -- all it took was two trips about five miles down the highway and a 12-pack of Bud. Pump, seals and gaskets were about $100. My guess is that if it is the shaft, you won't need to re-shim anything. Just put her back together and go.

[This message has been edited by avickers (edited 06-10-2001).]

[CDMA]

Thanks Avickers. I think if it was the shaft there would be no forward gear at all. Those pinion splines might be it. What about the dogs??? I am running a stock 260. Also if I am correct the gear change is in the top so lets say I got a 1.65 ratio drive the lower units would be the same right? Does this sound like anything in the top of the drive or can I be fairly sure it is the lower part?

Thanks

Chris

[BigGrizzly]

Top goes first, You didn't do anything that the drive shouldn't take. you have under 400 it shouls take that. Check the u-joints too. Don't feel bad my trans is starting to slip at high speed. There have been too many Bahahaha in my neighborhood.

Randy

[CDMA]

So top goes first. I agree the drive should be ok but it came off a 22 Donzi with a 300 hp tempest that I know for a fact the guy beat the crap out of it. Enough so to crack the floor behind both seats. I really am in a jam. I have finals for the next 2 weeks so the only way I could get it on now is just to buy a rebuilt unit but I am short he cash for it. Anyone have a line on a good used 1.5 ratio unit???

Chris

Hey harbor master don't you have one forsale???

Scott Pearson...you rebuilt yours right??? any thoughts

[Bryan Tuvell]

Sorry to hear about the drive unit.
I blew mine at the AOTH, when mine went she locked up tight preventing the engine from starting.... I saw the inside of mine, I about crapped, my mechanic said the top and bottom went, one, then the other, NOTHING was salvagable.

About all I can say is I wish you luck in the repair. Keep us posted.

Bryan

[CDMA]

Ewwwwwwww Hope mine is better than that.

Chris

[DonziDave]

I'm with BigGrizzly - Before you tear into the drive, check the u-joints first. With the drive up the u-joint is at an pretty steep angle. Overspin it, get a big torque load when it bites again, and BANG!!
Dave

[Donzitester]

Unfortunatly the upper and lower share the same oil supply, thus if one blows up the other will need to be rebuilt also due to
metal shaving contamination thruout the entire unit.

[CDMA]

Hey guys keep your eyes out for a good used drive. They aren't hard to find I just would rather buy something through someone as opposed to ebay or something like that. ALso I may be able to get a really good deal on a 1.65 unit. Would I be better off spinning a 21 pitch prop with a 1.5 or a 23 with a 1.65. My naval architecture training says a 1.65 spinning a 23 should be slightly more efficient.

Chris

[Scott Pearson]

Chris,
I went over my whole drive. Took the whole thing appart. Glass beaded it, painted it and put the whole thing back together.

My drive was in pretty good shape. I replaced all the seals, Bearings, u-joints, etc. The only thing that was a bitch was my threads for the shifter cable where shot. I had to buy a pipe thread helicoil kit and fix it. The kit alone was $175.00.

Its a piece of cake to take apart. I would check the u-joints first and go from there.

Or maybe its your pressure plate...Thats what I call it. You know the piece thats bolted to the flywheel. Maybe thats bad. If the rubber dryrots and breaks loose from the housing it would do the same thing like you said. It would allow you to limp it back but not under alot of power.

Just a thought...Good luck

(NJ)Scott

[CDMA]

Scott,

Could be the pressure plate however it is brand spanking new. How could I test that?

Chris

[jaroot]

Murphy at work again... i feel your pain... Jasper builds remanufactured uppers and lowers or complete assy's if you want to look at that route... last time i put one on i think it was something like 1/2 the price of a new merc piece. As far as the engine coupler when the rubber hub goes you'll be good at lower RPM where there isn't much load and then you'll slip.. it'll be hard to even get on plane... and usually there is no noise since the rubber is just spinning against rubber or the inside of the metal hub... but if you pull the drive and look through the gimble bearing with a good light you'll see melted rubber around the rubber hub... let's pray it isn't so but on mroe than one occasion i've seen the upper gearset go and still let ya idle your way home... and it sure doesn't sound pretty with chunks of gear going around in there.. and more likely than not.. when they go they take the inside of the housing with em... First things first though i'd pull the drive... get it in a stand and check out the U-Joints, if they are good spin the drive over... you'll be able to feel if there's anything reaaaally wrong, and just to make sure if you want to look you can pop the top gearset cap off the alpha and look at the upper gearset, just seals with an o-ring if my memory serves me correctly. hope it's nothing major... i remember all too well the college days and being poor...

Jim

[Scott Pearson]

Chris,
New always doesnt always mean NEW. I found that real quick with my ignition switch.

I really dont know how you would check that without taking it apart. Maybe take the drive off and get some one who has a old splined shaft and put it into the pressure plate and give it a turn. If it moves without turning the motor over you know you have a problem.

(NJ)Scott

[duckkilr]

If your engine coupler went bad, you would most likely smell a burnt rubber smell coming from the engine compartment. (Been there, done that).

If you do need a new drive, there is an outfit out of NJ called Marine Power Service that sells brand new Merc Alpha drives for $2,500 and rebuilt units for $2,000, both with a one year warranty.

If you did snap the input shaft at the splines, I don't think it would move at all. Been there and done that too!)

------------------
'87 Donzi Z-25
454 HO
Alpha

[marcdups]

Chris, what alpha model do you have and what year, may have a top or bottom unit, for 91-2 and up.
Marc

North of the equator,south of the pole

[CDMA]

The drive is a 87 I believe... gen one.

[CDMA]

No one knows where to find a good used 1.5 alpha...common guys....

Chris

[BigGrizzly]

Your training is correct about effiency untill you start spinning a 30 inch or better then it becomes a paddel wheel of sorts. Your Volvo was 161:1 wasn't it.

Randy

[marcdups]

chris, Ineed to know what side of the drive it is and a serial # upper or lower, I can help but need more info asap.
Marc

[CDMA]

Ok I will get right on it. I am at school and a bit away from the boat but I should be able to get my dad to do it. Where can I find the serial #???

Chris

[marcdups]

shoud be on the upper drive decal, but need to know if you need upper or lower{port side} worst come to worst may be able to get you a merc one rebuilt, which is new at cost, donzi guys, know what I mean, but do need the info.
Marc

[CDMA]

Marc

The decals are long gone. I stripped the drive this winter and painted it with a 2 part. Sure looks nice. I am not sure where to find other markings. Thank you for your help though it is much appreciated.

Chris

[marcdups]

do u need the lower or upper???

[Dalelama]

I lost my Alpha on the Minx last fall.... $1500 for a rebuilt unit (I know where there's 20 unit ready to go, all kinds of geat ratios... you just gotta drive to Miami to pick 'em up)

Unless you're a master wrench, I'd advise against doing it yerself.... although when I was in school I did EVERYTHING... couldn't afford to pay for anything!

Pop off the top cap on the upper... see if there's any metal shavings, parts, ect.

Good luck!

[CDMA]

Marc,

I think I am looking for a upper and a lower. I can't know for sure for a few more days. What I would like is just to buy a complete working drive and keep this as a spare.

What do you guys think of this

1989 Larson 19
5.0 1.65 drive
nice trailer
rotten floor
12 hours since new one owner.
$1200

Think I could pull it off??

Chris

[marcdups]

that sounds like a deal I would jump on that if the drive looks good.
Marc

[Kong]

Chris - Sorry to hear about your alpha. Want your Volvo back?? My old 200 is rumbling and I'm sure it will go soon. I have a line on a couple of used alphas - under 900 each. I have no idea of the specifics but if you are interested I can check out for you. I think they have had some rebuilding done to them.

[Bryan Tuvell]

Chris, the Larson deal sounds good, hell you could part out the rest of the boat and get some $ return.
My new Alpha Gen II was $4158 and $232 Labor.

I sure hope a deal works out for ya soon, being broke boat is no fun, I was boatless 3 weeks and it blew!
Good luck and keep up posted....
Bryan