afraid of Very Bad things/merc outdrive

ziggy

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Jun 30, 2004
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7,473
Re: afraid of Very Bad things/merc outdrive

yep for alpha1..

but 14 if it's gen II...

or 1,2,4 if it's pre alpha or 5 if its a 78-93 tr or trs....;)

if bravo, 11 or 28 it looks like...

adults only #9 has the selection available.... choose your poison..

looks like that is a significantly more involved repair?
anything in the drive that breaks is gonna be significant. special oem tools to do the deed will kill ya for dollars, let alone parts. then there's the knowledge to do the deed too. get your manual and read up. the manuals have the exact facts in them as how to do repairs.... between that and this fourm, a fella can do almost anything. if ya got the bread...
note what fm said too about his double failure. a new drive for him seemed the best route to go at that point for him....

need to find your issue first though. start yer hunt...
 
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nola mike

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Re: afraid of Very Bad things/merc outdrive

seemed the best route to go at that point for him....

need to find your issue first though. start yer hunt...

thanks for all the help guys. yup, i'll start the hunt on monday and keep you updated. been looking at the shop manuals, which is the only reason i have any idea what any of you are talking about. unfortunately, the diagrams in the manual don't show the whole outdrive at once, so kind of tough to visualize. i'm sure it'll be more obvious once i'm in there. here's a better diagram:
http://www.boatdesign.net/gallery/showphoto.php/photo/902/size/big/cat/
#49 on there is the part in question (i have an alpha 1).
we'll know more on monday...
 

ziggy

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Re: afraid of Very Bad things/merc outdrive

unfortunately, the diagrams in the manual don't show the whole outdrive at once, so kind of tough to visualize.
only place i can find or think of right now for a cutaway pic of the whole drive is in s/m #2.... kinda a big file to download just for one pic though... on the other hand... that'd just be one more s/m ya'd have in your collection.... ;)
 

CheapboatKev

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Re: afraid of Very Bad things/merc outdrive

Hope this is of some help

sterndrivecutaway.jpg
 

Bt Doctur

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Aug 29, 2004
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19,315
Re: afraid of Very Bad things/merc outdrive

The gears can be destroyed in "A"
The other 3 depict the most likely areas for shaft breakage in the MC1 pic
 

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CheapboatKev

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Re: afraid of Very Bad things/merc outdrive

I'll just take Bt's pic a bit bigger for you.
It's about all the help I can give..lol

MC1.jpg
 

nola mike

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Re: afraid of Very Bad things/merc outdrive

thanks--very helpful. the 3 marked places are all the same part, the drive shaft. however, i'm wondering if an isolated failure of the upper gears in "a" would result in my symptoms. it seems that i would still need a failure of the driveshaft, correct?
 

Bt Doctur

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Aug 29, 2004
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Re: afraid of Very Bad things/merc outdrive

You would have to drain the oil,(if any) remove the top cap ,and look inside to see if there are teeth on the gears.
44593f1f.jpg
 

nola mike

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Re: afraid of Very Bad things/merc outdrive

ok, so it was both gears in the upper gearset, probably due to being lubricated by the milky watery fluid that was passing as my gear oil. i also found that there was a leak into the shift cable area--this allowed a touch of water into where the u-joint lives, but it didn't look like m uch in there. grease was still intact, smooth gimbal bearing. i don't think this leak would be related to the drive failure, right? i must have another leak... on to the questions. 1. can i just replace the upper gearset here, and do i need special tools aside from the bearing retainer wrench? 2. how do i track down my leak? i've seen stuff on pressurizing the drive, is that what this is for? 3. local marina has a used outdrive for $500--what's a good price for one, keeping in mind that im not in a hurry for several months? 4. what gearset do i have in my '86 mmerc 170? i think it's 1.84, but how can i tell for sure? let me see if i can post some pics; the input gear was smooth, and the driven gear chewed up.
 

Fishermark

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Oct 19, 2003
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5,617
Re: afraid of Very Bad things/merc outdrive

You will have metal throughout the whole drive. I would say that the lower gears will be the next to go, and soon - if you simply fix or replace the upper.

You can shop around for used drives, but as I mention above, the aftermarket Sterndrive Engineering drives are hard to beat - come with a good warratny and everything.
 
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