MarineEngine.com - Your online store for all types of marine engines and boat parts.
PHONE ORDERS
Monday - Friday
9:00 AM - 5:00 PM EST
Click for TOLL-FREE Number
Online Checkout
Special $9.95 Flat Rate Shipping
(800) 209-9624 | Home | Contact | Shipping | Returns | Cart View your shopping cart.
Part Number Search
Shop by engine/drive part number.
Original & matching parts for sale.
Manuals & Accessories
Shop by description, item number
or manufacturer's model number.
Boat Repair Forum Boat Repair Forum   Boat Video Gallery Video Gallery
   
Results 1 to 11 of 11
  1. #1

    Default Mercruiser gearbox failure

    Hi,

    We had a bit of a drama out on the boat yesterday and I am trying to get a better idea of what might have gone wrong. Any help is appreciated!

    Mercruiser 5.0L with stern drive. While maneuvering at slow speed there was a strong smell of burning clutch and then the boat would not engage forward or reverse gear, the linkage was jammed in the central neutral position.

    What is likely to be the failure and what is involved in replacing gearbox components in a stern drive? Does the motor need to be removed or can these components be accessed from the stern? Is this type of problem usually caused by something jamming the prop or normal wear?

    Regards,
    Jesse

  2. #2
    Join Date
    Jun 2006
    Location
    Spotswood, NJ, USA
    Posts
    2,710

    Default Re: Mercruiser gearbox failure

    1 Check the oil level and condition
    2 Let us know the results
    The drive can be removed for service. no need to touch the motor.

  3. #3
    Join Date
    Mar 2009
    Location
    Lowell, MA
    Posts
    1,211

    Default Re: Mercruiser gearbox failure

    Well a Stern drive doesn't have "clutches" to burn, but it does have a "Engine Coupler" that will burn and smoke and when it does, you can engage into forward or reverse but it wont do much or anything, especially in the water... and if it's really bad, nothing out of the water.

    To check before removing the drive, with the boat running and in the water, and tied to a dock, put the boat in gear and look to see if the shaft coming out of the BACK of the engine is turning, If not.. engine coupler. If it is.. then you've got something else bad. ( but the outdrive doesn't have clutches like a car/truck and wont' Smoke unless highly overheated - at that point burning the paint of but I would think the bearings & gears would be destroyed at that point. )

  4. #4
    Join Date
    Apr 2006
    Location
    , Langkawi, Malaysia
    Posts
    5,750

    Default Re: Mercruiser gearbox failure

    'the linkage was jammed in the central neutral position.'

    But this would not happen with a burned out coupler???

    My guess, is a combination.
    Drive seized, coupler overloaded and burned out!

  5. #5
    Join Date
    Mar 2009
    Location
    Portland, Oregon,
    Posts
    7,230

    Default Re: Mercruiser gearbox failure

    Quote Originally Posted by haffiman37 View Post
    'the linkage was jammed in the central neutral position.'

    But this would not happen with a burned out coupler???

    My guess, is a combination.
    Drive seized, coupler overloaded and burned out!
    Given the above, "Ockham's Razor" may come into play here!

    This is near impossible to diagnose on the forum. You will want to pull the boat and do some testing.... and possibly remove the drive!
    From there you may be able to determine the condition of the coupler splines by inserting the alignment tool in hopes of seeing, or not seeing, metalic residue!
    The rubber coupler hubs generally don't let go from the smaller engines, but the splines may if the drive locked up and/or if the engine alignment had not been routinely performed!
    Strange that this would wait and occur at low speeds!
    Rick ... aka Ricardo
    Portland, Oregon
    28' SDN F/B w/ twin Volvo Penta 5.7L DP's

  6. #6
    Join Date
    Mar 2008
    Location
    Manalapan, nj, usa
    Posts
    3,727

    Default Re: Mercruiser gearbox failure

    remove the top cap of the drive easy to do 4 screws, see all chewed up gears?

  7. #7
    Join Date
    Aug 2009
    Location
    Sydney, NSW, Australia
    Posts
    195

    Default Re: Mercruiser gearbox failure

    ""Ockham's Razor" may come into play here! "

    hmmm. The simplest explanation.

    Burning smell followed by jammed gear selector.

    The gear select cable has melted onto the exhaust tube and jammed up gear selection. JM2CW. Mark.

  8. #8
    Join Date
    Mar 2008
    Location
    Manalapan, nj, usa
    Posts
    3,727

    Default Re: Mercruiser gearbox failure

    Would " Ockham's Razor " demand all the known facts be presented before a theory was put forward for a solution ?

    So tuna my man, my main man tuna, you suggest what, as to finding the solution? Removing the cable at the converter, and then moving the lower cable to see if it shifts ?

    Wouldn't that be better then posting some obscure theory, and giving no explianation of said theory.

    Or was posting such theory with no explaination a way to show your superior intellect ?

    I can believe the cable melted cause it was coming into contact with the riser or mani. I don't think the mani, gets that hot, or the riser to melt the cable but could be.

    Could be a freekin alien droped into the guy's engine room and the heat from his spaceship f--king melted his cable could be.

    Could be the cable was somehow in contact with a pulley, and the freekin pulley melted his cable.

    I think BT Docture has enough expierence that would suggest his theory is more plausible. Why ? Cause he probably seen this chit before.

    Why the burning smell ? Hmmmmmm the drive froze for whatever reason and the coupler, started to spin the rubber part that is, hence the smell.

    Why would the drive freeze hmmm water in the drive maybe, and then a gear went and wola frozen drive, upper maybe, maybe lower hence the" clutch " dog can't do whats dog's do go back and forth.

    Drives do have a clutch but it's not a auto or bike clutch but still a clutch.

    Enough with thhis Razor crap from some guy in the 12th century that didn't even come up with the theory. Yea i heard it before, some guy tried that stuff in aircraft school 40 years ago, he too was told to cut out that razor crap.

  9. #9
    Join Date
    Jul 2008
    Location
    , sc,
    Posts
    94

    Default Re: Mercruiser gearbox failure

    Couplers do fail even when the drive hasn't "locked up". If the shaft ian't turning, it will not shift into gear. Look closely in the area where the shaft goes into the back of the engine - often there is rubber dust that has been slung around = coupler failure. None there? Pull the drive and check the splines - metal particles, rounded corners = coupler failure.

  10. #10
    Join Date
    Mar 2008
    Location
    Manalapan, nj, usa
    Posts
    3,727

    Default Re: Mercruiser gearbox failure

    My coupler went no rubber on it all metal and yes they go without the drive freezing, and or hitting something with the prop.

    What year this drive and motor?

  11. #11
    Join Date
    Jul 2008
    Location
    Northboro, Ma, USA
    Posts
    3,452

    Default Re: Mercruiser gearbox failure

    A whole lot of answers but no reply from original poster...........maybe let this one go until we hear back.

    Opinion are like.................U know what!

Similar Threads

  1. md7 gearbox
    By pooliepete in forum Volvo Penta Diesel
    Replies: 0
    Last Post: 09-28-2010, 06:34 AM
  2. Gearbox failure on yanmar 54hp
    By shaunh in forum Yanmar
    Replies: 5
    Last Post: 03-29-2010, 09:14 PM
  3. Buzzer alarm and engine failure on a mercruiser 2001 5.7 EFI engine
    By mich in forum Mercruiser Sterndrive Forum
    Replies: 6
    Last Post: 02-17-2010, 08:44 PM
  4. SUZUKI DF200 4 stroke gearbox failure
    By sandgroper in forum Suzuki Outboard Forum
    Replies: 2
    Last Post: 02-13-2010, 03:01 AM
  5. MD1 Gearbox
    By pablo121 in forum Volvo Penta Diesel
    Replies: 1
    Last Post: 03-25-2009, 09:13 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •