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1984 75hp lower unitcurrently off shifting probs

M

modulistic

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"so I got a project 84 merc fo

"so I got a project 84 merc for free and ive been slowly going through it. the current problem is it is stuck in forward. I have the lower unit off currently and looking down turning the shaft counter clockwise, the propeller only turns in the forward direction. I turn the shift selector all different directions with no "click" and no difference in how the prop turns. also, the shaft is difficult to turn. what could be wrong? also, I dont see a place to put in lube for the lower end... where is this supposed to go in?"
 
"Scott,by the sound of it you

"Scott,by the sound of it you have a broken shift cam in the lower unit or at best the shift shaft has been pulled from the shift cam and it has dropped out of line.
If you look at the lower unit with the prop on your right, you should see two screws.One at point of the "bullet",the fill screw, and one in the center just above the cavatation plate,vent screw.
Fill from the bottom with the unit upright until the fluid comes out the vent screw."
 
"ok so I got the spin nut and

"ok so I got the spin nut and the locking retainer off, but part numberr 63 doesnt want to come out. does it press out or spin out? it has a locking key that is flush with the unit. i cant get that key out so I assume it presses out, but it isnt really budging, which makes me afraid that it turns out.

also, the screw near the bullet is on the bottom of the bullet, and the vent is way higher. how do you fill the fluid uphill like that?"
 
"it presses out.

ok so I

"it presses out.

ok so I now kinda see how it works, part number 56 slides back and forth between the two gears and engages the ears on each gear. that part was slid all the way forward which is why it would engage when the drive shaft was turning in the normal direction, but make clicking sounds when i spun the prop in the reverse direction. that piece 56 doesnt want to slide very well. Im going to wait until some of the grease drips off and Im going to try and free that mechanism. everything looks really new which coincides with the previous owner saying the lower end had been rebuilt."
 
alright well the lower is back

alright well the lower is back together and shifting. I learned first hand what everyone is complaining about the little pin that keeps falling out. now I just need a rubber grommet for the water outlet tube going up to the powerhead and figure out how to get lube back in the gearbox.
 
"Scott that's some work,me

"Scott that's some work,me,I'd be at it for a week.
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Buy a mercury lower unit lube filler. It screws into the fill plug hole,the bottom one,the pump fits on the bottle of lube and just pump until the lube appears at the vent.Put in the vent plug,remove the filler and quickly screw in the plug.You will drop a little lube but nothing to worry about.Be sure to replace the two plug gaskets.And don't do what I did and leave the old ones in place
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"
 
"thanks. everything is back t

"thanks. everything is back together and it seems to be shifting. I hope I got the water tube stabbed right. Im going to mess with some of the wiring, but I dont have a wiring diagram. so far Ive replaced the starter, the stator, a mess of wire, the lower unit shifting problem, etc.

Im going to fire her up tomorrow hopefully."
 
"thanks for those links, that

"thanks for those links, that cleared up quite a bit. Ive been cranking on it a little bit, but I only have spark at the #1 cylinder. got a little bit more trouble shooting to go."
 
"looks like I had the stator t

"looks like I had the stator turned about 90 degrees out, cause I thought I could just bolt it down any which way. I didnt pay attention to the white marks someone made on the new stator with fingernail polish, but now theres a wire crumbling on the trigger and I chased it all the way back to the body of the trigger. the other wires seem fine, just this one wire is rotten as hell. I might try to crank it over even with this one wire disconnected just to see what the heck it does. its the black white wire."
 
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