shaft seized to power head-your experience

pine island fred

Lieutenant Junior Grade
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Dec 20, 2002
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Just replied on another post and it occured to me that this may not be a common problem. Any one else out there experienced this problem? Clymers and Selock manuals mention this could occure. Happened to me, rendered a 40 hp. 4 cyl useless. regards fred
 

Laddies

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Re: shaft seized to power head-your experience

Yup, if the lower unit is run low on oil it will seize the driveshaft brg.
 

TOHATSU GURU

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Jul 22, 2004
Messages
6,164
Re: shaft seized to power head-your experience

Driveshafts get stuck into crankshafts usually due to a seal or boot failure...Or bad luck. They will usually come loose if you wait long enough. Sometimes you can pull the powerhead off and seperate them that way.
 

rodbolt

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Sep 1, 2003
Messages
20,066
Re: shaft seized to power head-your experience

mostly the crank splines seize to the shaft splines due to excessive maint. my experience is the splines or lower bearing fails after a forcible seperation, if it ever seperates.<br /> never seen it happen on a properly maintained rig.
 

Laddies

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Re: shaft seized to power head-your experience

Fred, sorry I thought you meant the driveshaft wouldn't turn in the lower unit, not that is was stuck in the crank--Bob
 

Chinewalker

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Aug 19, 2001
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8,902
Re: shaft seized to power head-your experience

Actually, I was going to say that the driveshafts stick do to lack of, or poor maintenance - not excessive maintenance. Most of the stuck shafts I've seen have been rusted into place - not twisted. A well-meaning but poorly informed shade-tree may not add a dab of grease to the top of the driveshaft splines prior to reassembly, or the o-ring may rot away, thus allowing moisture to get into the crank splines and rust up. Particularly bad on older Mercs that had both carbon steel driveshafts and crankshafts. At least OMCs have used stainless shafts since the 1940s... Merc didn't figure that one out until the 1970s.<br /><br />I've had some success by sacrificing the mid-section and cutting the driveshaft at the powerhead. You can then drill out the shaft from the crank and pull the splines out in pieces. Doesn't always work, but I've salvaged a few that way...<br /><br />- Scott
 
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