Boat

Have Boat Questions? Ask a Boat Repair Expert.

Ask an Expert,
Get an Answer ASAP!

I have an alpha 1 outdrive and hit a rock with the prop. The…

Customer Question
I have an alpha 1...
I have an alpha 1 outdrive and hit a rock with the prop. The output shaft of the engine is turning, but the prop is not. Where is the most likly failure?
Submitted: 8 years ago.Category: Boat
Show More
Show Less
Ask Your Own Boat Question
Answered in 12 minutes by:
10/3/2009
Marine Mechanic: Rick Gay, Marine Mechanic replied 8 years ago
Rick Gay
Rick Gay, Marine Mechanic
Category: Boat
Satisfied Customers: 106
Experience: 30 yrs experiance,certified raymarine electronics installer,certified mercruiser mechanic,
Verified
Hi,
My name is XXXXX XXXXX seen is the top part of the drive shaft in lower half shears off with an impact.You will have to split the 2 halfs to be able to see.You could also [with engine off] is to put it in forward gear and try to turn the prop.if it turns really easy the shaft has sheared.

I hope I have helped.
Thank you for using just answer.
Rick
Ask Your Own Boat Question
Customer reply replied 8 years ago
I have pulled the outdrive off the boat. I turn the input shaft and the prop does not turn. When in gear, the prop turns only one direction. I pulled the input shaft assembly and looked at the first section of the verticle shaft. On the verticle shaft there is a small upper bearing a gear, and a lower bearing. Below the larger bearing, the shaft is not directly connected to the lower verticle shaft. How is power transmismitted to the prop?
Marine Mechanic: Rick Gay, Marine Mechanic replied 8 years ago
Hi,
The power is transmitted to the prop thru the driven gears in the upper gear case.Which the shaft that has the small bearing on top of it in the upper housing, that shaft has splines inside it under the gear.then the shaft[#71] in diaghram goes into it when the 2 halfs go together. you will see splines at the top of that shaft. If you dont then shaft has sheared below splines.You can follow this link to see the breakdown of the lower unit and the drive shaft I am talking about.
Hope this helps
Thanks
Rick

http://www.sterndrive.info/sitebuildercontent/sitebuilderpictures/MWM-Mercruiser-parts-layout-1-24-illustrated-lower-unit-drawing..jpg
Rick Gay
Rick Gay, Marine Mechanic
Category: Boat
Satisfied Customers: 106
Experience: 30 yrs experiance,certified raymarine electronics installer,certified mercruiser mechanic,
Verified
Rick Gay and 87 other Boat Specialists are ready to help you
Ask your own question now
Was this answer helpful?

How JustAnswer works

step-image
Describe your issueThe assistant will guide you
step-image
Chat 1:1 with a marine mechanicLicensed Experts are available 24/7
step-image
100% satisfaction guaranteeGet all the answers you need
Ask Rick Gay Your Own Question
Rick Gay
Rick Gay
Rick Gay, Marine Mechanic
Category: Boat
Satisfied Customers: 106
106 Satisfied Customers
Experience: 30 yrs experiance,certified raymarine electronics installer,certified mercruiser mechanic,

Rick Gay is online now

A new question is answered every 9 seconds

How JustAnswer works:

  • Ask an ExpertExperts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional AnswerVia email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction GuaranteeRate the answer you receive.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... Justanswer.com.
JustAnswer.com...has seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like justanswer.com/legal
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help.

Mary C.Freshfield, Liverpool, UK

This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!!

AlexLos Angeles, CA

Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult.

GPHesperia, CA

I couldn't be more satisfied! This is the site I will always come to when I need a second opinion.

JustinKernersville, NC

Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around.

EstherWoodstock, NY

Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know.

RobinElkton, Maryland

He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here.

DianeDallas, TX

< Previous | Next >

Meet the Experts:

Dominick

Dominick

Marine Mechanic

1,009 satisfied customers

25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified

Ted G.

Ted G.

Rigger, Diagnostician

703 satisfied customers

40 years boating, Safe boating instruct., Offshore Race promoter, Failure Analysis, Expert Witness

John White

John White

Marine Mechanic

306 satisfied customers

11 years experience working on outboards, inboards, sterndrives & pwcs

Jason

Jason

Marine Mechanic

16,838 satisfied customers

Degree in Marine Technology. Gas and diesel marine mechanic.

Tan

Tan

MerCruiser Certified Technician

11,179 satisfied customers

40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.

Jeff G.

Jeff G.

Marine Mechanic

4,728 satisfied customers

42 years experience, Certified Master Technician, All Major Outboards, Sterndrives, Hi-Performance

Captain Dave

Captain Dave

Marine Mechanic

2,672 satisfied customers

USCG Licensed Captain, 20+ Years Boating, Fishing, Maintenance and Repair Experience

< Previous | Next >

Related Boat Questions
Trying to put my Alpha 1 outdrive on and when i went to turn
Trying to put my Alpha 1 outdrive on and when i went to turn the prop counter clockwise to line up the splines i cannot turn the prop counter clockwise. … read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
Boat is a 2005 bayliner 245 sb 5.0 mercury with alpha
Boat is a 2005 bayliner 245 sb 5.0 mercury with alpha outdrive, I was cruising at about 25mph and all of a sudden it slowed right down to nothing and the engine was racing but did not seem to connect … read more
Clamp-onTech
Clamp-onTech
405 satisfied customers
Tan, I t a sandbar and some rock with my lower unit which
Hi Tan, I hit a sandbar and some rock with my lower unit which caused some damage to the prop and scraping on the lower unit and skag. I was able to restart the engine and put in drive however after r… read more
Jeff G.
Jeff G.
Marine Mechanic
Vocational, Technical or Trade Scho
4,728 satisfied customers
My Alpha 1 outdrive is 18+ years old now and has recently developed
My Alpha 1 outdrive is 18+ years old now and has recently developed a grinding noise when running in certain trim positions and when turning. I have checked the outdrive grease and actually replaced i… read more
Jeremy R
Jeremy R
1,069 satisfied customers
I have a wellcraft scarab has twin 350s with alpha outdrives.
I have a wellcraft scarab has twin 350's with alpha outdrives. The left engine blows out and engine revs up when taking off. So I can't get it up on plane, the lower unit is all the way down and it sm… read more
Whitecap36
Whitecap36
Service Manager/Technician
Vocational, Technical or Trade Scho
1,476 satisfied customers
Have a 4.3 mercruiser with alpha one outdrive, have no power
Have a 4.3 mercruiser with alpha one outdrive, have no power to outdrive. Is there a torque converter or flywheel?… read more
Jason
Jason
Marine Mechanic
Vocational, Technical or Trade Scho
16,838 satisfied customers
i just changed the impeller in my outdrive(alpha 1) now when
i just changed the impeller in my outdrive(alpha 1) now when i am putting the lower unit back on the prop is just spinning what do I need to do to get it to stay in gear? I took it off in gear I figur… read more
James
James
Certified Marine Mechanic
Vocational, Technical or Trade Scho
4,094 satisfied customers
How to remove a Mercury Alpha One lower unit from the outdrive?
How do I remove a mercury alpha one lower unit from the outdrive? It is on a 1990 boat. This one won't shift and I think the previous owner didn't hook something up right.… read more
Tan
Tan
MerCruiser Certified Technician
Certified Marine Technician
11,179 satisfied customers
I have a mercruiser outdrive on a 50 houseboat. Think it
I have a mercruiser outdrive on a 50' houseboat. Think it is a '75 model 228. The outdrive has a 1 1/8 " spline and uses a 17 inch 13 pitch prop. All this, I have been told by those trying to help me.… read more
Jeff G.
Jeff G.
Marine Mechanic
Vocational, Technical or Trade Scho
4,728 satisfied customers
I have a 2003 mercruiser alpha leg,I hit a rock and a piece
I have a 2003 mercruiser alpha leg,I hit a rock and a piece of metal below the prop broke off. there dosn't seem to be any vibration. Should I take it in for checkup?… read more
capt ron 1959
capt ron 1959
Owner/Marine Mechanic
Vocational, Technical or Trade Scho
348 satisfied customers
I have a 4.3 litre V6 Mercruiser with an Alpha one outdrive.At
I have a 4.3 litre V6 Mercruiser with an Alpha one outdrive.At full throtle the rpm's max out but the Prop doesn't come along for the ride.At 45 mph the trouble starts, but the boat doesn't speed up a… read more
James
James
Certified Marine Mechanic
Vocational, Technical or Trade Scho
4,094 satisfied customers
I have a 4.3 l mercruiser, Today i was on the water and went
I have a 4.3 l mercruiser, Today i was on the water and went to take off and it went about 10 feet then stopped. The motor ran but the prop was not spinning and as i was trying to figure out why the p… read more
James
James
Certified Marine Mechanic
Vocational, Technical or Trade Scho
4,094 satisfied customers
Hello, I recently purchased a used 2007 Chaparral 210 70 hours/5.0/
Hello, I recently purchased a used 2007 Chaparral 210 70 hours/5.0/ Alpha 1. The previous owner said he hit something and damaged the prop, and there is a small nick in the bottom of the outdrive (1/4… read more
Jeremy R
Jeremy R
1,069 satisfied customers
I have a 1977 25 sea ray with a 228 mercruiser , looking for
I have a 1977 25' sea ray with a 228 mercruiser , looking for a used outdrive ,right now checking out a 1979 pre-alpha and my question is will it fit and what should I look for?… read more
capt ron 1959
capt ron 1959
Owner/Marine Mechanic
Vocational, Technical or Trade Scho
348 satisfied customers
Have a 4.3 v6 with a mercury alpha one outdrive. Have low speed
Have a 4.3 v6 with a mercury alpha one outdrive. Have low speed capabilty, but when throttling up it slips and high revs....can anyone tell me my problem and what to do to fix it?… read more
Captain Dave
Captain Dave
Marine Mechanic
Master's Degree
2,672 satisfied customers
replaced both engines this year and when out on saturday..
replaced both engines this year and when out on saturday.. engines were running at about 3,000 rpm .. boat was moving nicely on plane when all of a sudden one engines rev;s up to 6,ooo rpms and i lose… read more
Captain Dave
Captain Dave
Marine Mechanic
Master's Degree
2,672 satisfied customers
I have a 2005 170LE Horizon Four Winns I/O with a Volvo 3.0GL.
I have a 2005 170LE Horizon Four Winns I/O with a Volvo 3.0GL. I hit a rock and the motor kicked up. No visual damage to the prop but some scrapping on the skeg. Motor is running fine with no vibratio… read more
Dr. Joe
Dr. Joe
Bachelor's Degree
198 satisfied customers
i have a 79 imperial with a 4cyl, 140hp mercruiser ...
i have a 79 imperial with a 4cyl, 140hp mercruiser outdrive. The other day on the lake my boat quit moving but the motor was still running then when i put it in gear it started smoking out of the back… read more
Ted G.
Ted G.
Rigger, Diagnostician
Vocational, Technical or Trade Scho
703 satisfied customers
Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Disclaimer: Information in questions, answers, and other posts on this site ("Posts") comes from individual users, not JustAnswer; JustAnswer is not responsible for Posts. Posts are for general information, are not intended to substitute for informed professional advice (medical, legal, veterinary, financial, etc.), or to establish a professional-client relationship. The site and services are provided "as is" with no warranty or representations by JustAnswer regarding the qualifications of Experts. To see what credentials have been verified by a third-party service, please click on the "Verified" symbol in some Experts' profiles. JustAnswer is not intended or designed for EMERGENCY questions which should be directed immediately by telephone or in-person to qualified professionals.

Show MoreShow Less

Ask Your Question

x