Mercruiser Alpha One Gen 2 - heavy knock in upper unit

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tyler9953

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Hey guys, I've got a 1994 Century 210 with the 5.7 Alpha One. I just purchased this boat about 3 weeks ago. I was told that they just replaced the gimbal bearing. So, I was out yesterday when I felt a little jerk. Nothing more till we were done for the day and then that same jerk, and then d consistent heavy knock. I was almost at the ramp, so I turned in and loaded up. I got home and checked the lower unit oil. There was a lot of pressure, and it shot oil with metal shavings out. The oil smelled burned. I put the muffs on and can feel the knock in the upper unit. I have read a bunch of posts and other websites info, and I think the u joint is gone. I guess I want reassurance that the u joint is indeed the issue. Again, this is a hard knock that does not fade or stop.
 
Don S

Don S

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Pull the cap off the top of the drive. I think you will see your problem.
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

I will do that today. I talked with a family friend today, and after telling him about the pressure in the lower unit (when I removed the seal plug) and the metalic look to the oil (metal shavings) he said it was deffinetly gear related. Is that what you think Don?
 
Don S

Don S

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Yeah, afraid so. the metalic oil tells the story.
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Don,

I am looking at a site, http://mercstuff.com, and I could order the parts I need. Looks like I will need a few tools that I wouldn't already have (like alignment tool). Is this something that you think someone with some mechanical experiance could do? I will order the repair manual before I undergo this task. I may end up just having a shop do it though. What you think? Thanks for all the help!
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Took cap off...yep, gears chawed up.
 
paultjohnson

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Mo$t unfortunate.....:facepalm: FYI the u joints aren't submerged in the gear oil... But thats the least of your worrie$ at the moment... When the gears go in the upper , the debris contaminate the lower. Ya cant just replace the upper gears and call it done. The lower will be failing next.:eek::(:) I think Turn n Burn has your be$t idea.... Be$t of luck.............
 
Bondo

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

tyler9953 said:
Don,

I am looking at a site, http://mercstuff.com, and I could order the parts I need. Looks like I will need a few tools that I wouldn't already have (like alignment tool). Is this something that you think someone with some mechanical experiance could do? I will order the repair manual before I undergo this task. I may end up just having a shop do it though. What you think? Thanks for all the help!
Click to expand...

Ayuh,.... Welcome Aboard,...
The Alignment Bar is a tool you'll use for along time, if yer gonna be an I/O Boater....

Pull yer drive off now, then you'll see the u-joints, 'n can inspect the rest of the transom assembly...

I'd also say grab yerself an SEI replacement drive...
The specialized tools to rebuild an Alpha run almost twice as much, or more...

Check out the Adults Only section at the top of this forum,...
Ya might find the factory Manuals for yer motor, 'n drive there...
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

This is all so sad...I think I must've got something with my stainless prop. I've heard that either your prop goes (if aluminum) or your outdrive. It couldn't have been much as I don't recall anything nor does prop show any signs. So will I HAVE to replace lower too? I will talk with a couple shops tomorrow about options and labor. The new units arnt to bad...just hate to buy both or whole new outdrive.
 
paultjohnson

paultjohnson

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

The hubs on most-but not all- SS props are made to fail before the drive is trashed from impact. There is like a rubber insert between the splined part that contacts the prop shaft, and the main body of the prop itself. Its sacrificial. Then you end up with a....spun prop. It made to save the drive and/ or prop, and you can get the prop repaired For a hundred or less.. Had you checked the lube level in the drive? It should be up to the top vent hole. If you were low on lube those top 2 gears will self destruct from lack of lube. The are the highest in the drive and starve for lube 1st if the level is low... I am not sure about the absolute need to replace the lower. But.... if you were running the drive with the upper gears self destructing, at least some of the the metal debris has probably been going thru the lower gearcase gears at least a bit, as they share oil................not good .................I feel 4 ya
 
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Turn-n-Burn

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

definitely need the lower replaced....as you can see here......http://www.sterndrive.info/alpha-one/parts_drawing_lower.html .....too many places for the metal shavings to chew everything up.....nearly impossible to flush it out....never mind the damaged already done.......I got lucky by getting a Konrad upper and pre alpha lower for near free and married them up until I get my SEI........it suxs when you can't find/don't know what the root cause was......Best of Luck!!
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Ok...so, i've talked with a mechanic that comes recommended by a friend who has a similar issue with his Crownline 5.0 Alpha One gen2. The mechanic says he can replace the gears in upper and lower if needed $300 labor. Said that he will know if they need it when he gets it appart. He said that I can buy the gears if I want or he can. He uses "Sierra" gears and has for a long time and has had good luck with them. The site I posted earlier in this thread (www.mercstuff.com) has a brand of gears, "GLM", that offer their upper rebuild kit for my ratio (1.50) for $324.95. That is everything. Does anyone have any experiance with either "Sierra or GLM" stuff? I can buy a complete upper unit used for $475, or new "SE" aftermarket for $750. New outdrive "SE" aftermarket is $1450...

If I can get away with fixing the gears for $700...I think thats what I'll do. The used Mercruiser upper unit for $475 is on ebay. It's a perfect match, but it's used and no warranty...don't think I'm gonna go that route. I really apprieciate the input and help guys. This is my first I/O.

BTW, I read this article about the upper unit rebuild: http://www.sterndrives.com/rebuild_alphaone_upper.html
I deffinetly won't try and do it myself. Sounds like I would be "messing with the other mans trick."
 
paultjohnson

paultjohnson

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

tyler9953 said:
Ok...so, i've talked with a mechanic that comes recommended by a friend who has a similar issue with his Crownline 5.0 Alpha One gen2. The mechanic says he can replace the gears in upper and lower if needed $300 labor. Said that he will know if they need it when he gets it appart. He said that I can buy the gears if I want or he can. He uses "Sierra" gears and has for a long time and has had good luck with them. The site I posted earlier in this thread (www.mercstuff.com) has a brand of gears, "GLM", that offer their upper rebuild kit for my ratio (1.50) for $324.95. That is everything. Does anyone have any experiance with either "Sierra or GLM" stuff? I can buy a complete upper unit used for $475, or new "SE" aftermarket for $750. New outdrive "SE" aftermarket is $1450...

If I can get away with fixing the gears for $700...I think thats what I'll do. The used Mercruiser upper unit for $475 is on ebay. It's a perfect match, but it's used and no warranty...don't think I'm gonna go that route. I really apprieciate the input and help guys. This is my first I/O.

BTW, I read this article about the upper unit rebuild: http://www.sterndrives.com/rebuild_alphaone_upper.html
I deffinetly won't try and do it myself. Sounds like I would be "messing with the other mans trick."
Click to expand...

I use alot of Sierra parts, and have had good luck. I have shied away from GLM and MALLORY cuz of all the bad press I have read on this forum. Tho I dont have any personal experience with either brand.
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

I made my decision: bought upper gears, upper seals, water impeller kit with all seals for lower unit.

My mechanic said he would go in, check lower gears, replace impeller, and seals while there. Since I only had one tooth gone, he said the damage was light, and lowers should be ok. We'll find out. Bought my gears and seals from Tungsten Marine. Talked with owner and really liked the guy. They use top notch gears/bearings and they stand behind product. I will let u guys know how it goes. I was told once up and running, to go easy on gears for a few hours. Let the gears get warn in. Then change outdrive oil sand refill with full synthetic.
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Mechanic took the outdrive off the other day and has started working on it. He has all the parts I ordered and said they look good. Apparently the gears that were in the upper unit were not the original 1:1.50's. He said they were the sporty gears. I'm guessing he meant the 454 type 1:1.3's. Anyway, the double bearing is going to need to be replaced, so I got online and got one today. He said for me not to get one until he could see if was any good or not. I guess it was no good. Good news is I found "Quicksilver" double bearing brand new on ebay for $31! With shipping and all it was $44 so I did good on that I think. The mechanic had me look at the housing in the upper unit once he had the gears out. Where the shaft goes into the housing it scared up the bottom a bit. He said it was not too bad, and he could machine it. That is where the gears are shimmed. I am looking forward to getting back on the water. Especially since it has been over 105* for a couple of days.
 
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tejastoolman

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

napa changed their part numbers for u-joints P315G put in 2 new ones last night for $22.00 incase anyone has a hard time finding them
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Got the boat back Saturday and took it out all day. I wanted to break the gears in so I ran around for probably 3 hours. Boat did great...no issues at. Took it out Sunday after church, and right off the launch, the upper gears started to knock. I immediatly shut it down loaded back up and my mechanic can look at it tomorrow. I am about $700 in right now, and wishing I would have bought a new outdrive and be done with it. I guess you guys told me so, but I was trying to save $$. May end up costing me more than it should have. Now the boating season is comming to a close and I just want my boat back. And btw, I did the break in just the way they told me to. No full throtle, no immediate throtle, not pulling, no harsh gear changes, etc. Don't know what happened. The mechanic said that he guaranteed his labor, and the gears are guaranteed. I am sure the mechanic (he is good guy) will blame on the gears though.
 
Volphin

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Oh man that stinks! Keep us posted on what he finds when he opens it back up.

V
 
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tyler9953

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Re: Mercruiser Alpha One Gen 2 - heavy knock in upper unit

Well, I'm getting back here a little late. I took the boat back in, and mechanic called me a day later and said it was the u-joint this time. He said he checked the one in the outdrive, when doing the gear repair, but he didn't check the one at the other end of the shaft, and that was the problem. He fixed it (parts and labor was $204) and I took it out next day, and it was perfect. He tuned the motor up a bit while he was at it, and it ran terrific. So, I ended up being out over $850 all total. I have new upper unit gears, new double bearing (and various other bearings), all new seals (upper and lower), new impeller, and new u-joint. I think I did OK, but I half regret not buying a new unit. We will see how long everything lasts'.

Two problems right now. First, my gear shift is a newer one, but going in reverse is a problem; it doesn't engage sometimes. I have to work the lever back in engine compartment to make it engage. The other issue is, with full throttle (don't worry, I put over 5 hours on engine before I went full throttle) I get to 3800 rpm...no more. At that rpm I am doing 46-48 mph (gps). Fast enough, but I figured this thing would go 4400-4500 rpm. Anybody with knowledge on a 5.7 350 Alpha One? My dad has the 460 in his 92' Cobalt and it will do 4500 rpm, so I know mine should.
 
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