Early 80's Johnson 140 will not go into forward or reverse

schooter

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Feb 21, 2008
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The other day my son and friend were running down the river on plane. It suddenly jumped out of gear as if it went into neutral. Since then it will not go into forward or reverse. I removed the prop thinking it had spun, it seems to be fine. With the prop removed I worked the shift rod up and down manually. It doesn't seem to matter what position the rod is in. The prop shaft spins freely in both directions. For a lack of better words, It acts like it is stuck in neutral. What do you think went wrong? Also, I am a back yard mechanic by default. Is this something that can be diagnosed and repaired by your average back yard mechanic?
 

racerone

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Dec 28, 2013
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Start by draining the oil in the lower unit.----Then remove lower unit and inspect spline on top of the driveshaft.
 

schooter

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Feb 21, 2008
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No Title

OK. Drained the oil. Pulled the unit. The spline doesn't look right. See pic. Can't be good news, but give it to me anyway.
 

schooter

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Feb 21, 2008
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OK. I am having trouble uploading the photo. The splines on the top of shaft look like they have been "sharpened" 3/4 way down. The remaining lower portion of spline appear to be normal. It looks like there was a abnormal amount of pressure on them. I will continue to try uploading the pic. My description is vague at most.
 

racerone

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Can you put it in gear now and turn the driveshaft to see if prop turns.?
 

schooter

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Feb 21, 2008
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I tried turning the driveshaft in all gears. The prop never turned. It only turns when I turn it by hand, but nothing else turns with it.
 

schooter

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Feb 21, 2008
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Yes. It feels like it is going in and out of gear when I push up and down on the shift rod. But it does not seem to affect the prop shaft at all. Its like they are not connected to each other.
 

racerone

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Dec 28, 2013
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Sounds like the driveshaft broke or pinion gear stripped the teeth off.---What did the oil look like ? ---clean = broken driveshaft.----Metal chips is gears.
 

schooter

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Honestly the oil looked pretty clean. If it is the driveshaft that is broken. How difficult would it be to change out? What should I know before attempting this, if I muster the confidence to do it? I have another complete lower unit, the casing is cracked on it. But driveshaft appears to be in better shape than the one I am (was) using.
 

NORTH81

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May 21, 2013
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I have a 1982 Johnson 140. I also got my hands on an OMC manual for it. It's been well used to say the least. Worth picking up for sure. That being said, a picture of the spline is worth a thousand words... Be glad to provide any textbook help i can.
 

schooter

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Feb 21, 2008
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Thanks! I'll, for sure, pick up a manual for it. However, I am a little hesitant to break into the lower unit. If its as simple as changing the shaft without getting into a complete break down, that's one thing. But I am getting the feeling its more complex than "simple". I am going to study this a little longer. Any advice is appreciated!
 
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