what to check when buying an outdrive?

[nola mike]

i blew out an outdrive about a month ago and have been looking for a replacement. I found one that seems like a good deal, and am going to look at it on monday. obviously, this is somewhat of a crapshoot with the drive off of the boat, but is there any way to get a feel of what kind of condition it's in? i can check the oil for starters--should i completely drain it to look for shavings, etc? checking forward/reverse, make sure everything engages cleanly, look for severe corrosion (it's a saltwater unit though, so i'm sure it won't be perfect). make sure u-joint moves freely. i'll replace the impeller anyway. anything else? i'd like to pressure test, but i'm not sure how feasible that is--i don't have any equipment for that at the moment (though i guess i can cobble something together by monday).

 

[boat1010]

Re: what to check when buying an outdrive?

The drain plug usually is magnetized so the meal should be on it if there is any. But I would suggest something in writing if there is a problem with it when you install it on your boat. If the guy is honest he should give you some sort of guarantee.

 

[TilliamWe]

Re: what to check when buying an outdrive?

Since you mention an impeller, I'll assume you are looking at a Mercruiser Alpha series drive. (I know it could be an OMC Cobra, too)
That said, rather than buying anything used (much less one used in saltwater) I would be looking at an SEI drive. For $1195 (Alpha One) or $1395 (Alpha One Gen 2) you have a BRAND NEW drive with a 3 year warranty that includes abuse and striking objects! No brainer.
And they are sold right here on iboats.

 

[45Auto]

Re: what to check when buying an outdrive?

Pull the top cap off (4 bolts, 12 point 3/8 socket) and look at the condition of the upper gears and bearing. It's very common down here for them to be rusted up if there's any water at all in the drive. The water boils off while they're running, then condenses up above the oil level when they're shut off and rusts out the gears and upper bearing.

 

[nola mike]

Re: what to check when buying an outdrive?

@TilliamWe: sorry, yeah, it's an alpha 1. i looked into an sei drive, and it seems like a good deal. however, i'm willing to take my chances with something used, especially given the price i'm paying for this one, and the price i paid for the boat.
@boat1010: a guarantee would be great, but no private seller would offer one, especially if i probably won't be using the drive until the spring.
@45Auto: good thought--i guess i'd have to drain the oil first? if the level's full, i wouldn't suppose you'd get the rust to begin with.

 

[Grumman59]

Re: what to check when buying an outdrive?

@45Auto: good thought--i guess i'd have to drain the oil first? if the level's full, i wouldn't suppose you'd get the rust to begin with.

You still might because the upper oil level does not completely submerge the drive gear so it's worth checking anyway. Just turn the shaft to look all around the drive gear.

 

[45Auto]

Re: what to check when buying an outdrive?

@45Auto: good thought--i guess i'd have to drain the oil first? if the level's full, i wouldn't suppose you'd get the rust to begin with.

You don't have to drain the oil. The oil level will only be up to the vent hole, which is 2 or 3 inches BELOW the cap on the outdrive. The upper bearing and part of the upper gear are ABOVE the oil level. That's the problem, any water that gets boiled out of the oil condenses in that air space and will rust the upper bearing if the drive isn't used regularly.

Went out and pulled the cap off an Alpha sitting in the garage. You can see where the vent screw is, and how there's an air space above it.

 

[rockyman]

Re: what to check when buying an outdrive?

to test it put it on a stand lock it in gear and turn prop if it turns smoothly and easy it should be ok,if its tight enough you cant turn it by hand yhere is probally a bad bearing somewhere in the upper or the lower.

 

[dubs283]

Re: what to check when buying an outdrive?

being that it is a saltwater unit, i would not recommend buying it

you have six months to find a better one

if you absolutely have to have this drive do the above suggested inspections and also:

-verify it is the correct ratio
-pressure test

 

[nola mike]

Re: what to check when buying an outdrive?

just an update. guy said the upper was freshwater, lower salt water. most of the drives in my area are going to be salt anyway. didn't look like it had a lot of corrosion though. it shifted and turned smooth, the oil initially (maybe 1/2 oz) was milky, then clean the rest of the way. he said he put in a new impeller and only used the drive once or twice. gearset up top looked clean. u joint felt good. gear ratio said 1.84 on the side, though i guess it could have been changed. he said it came from a 470 though, and had the motor sitting there, so no reason to doubt that. i didn't have a chance to make a pressure tester, but i figure there's probably at least a small leak somewhere. i gave him $200 for it, plus it came with a SS prop, so worth the gamble.