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1981 115hp Merc no forward or reverse gears.

B

Bassky

New member
Motor will not shift into forward or reverse. Shifter works but the no gears. Looked at the linkage for the shifter, couldn't figure out what is going on there. Hopefully, it isn't a bad gear. I don't understand what may have happened?
I ran it last December and everything was working fine, no grinding or hard shifting, everything was fine. Any ideas? Changed the lower unit oil, had some water in it. Drained and replaced lower unit oil. Still no gears when shifting.
Thanks,
Bassky
 
Was the lower unit off this thing ?????----------Have you replaced the seals to keep water out of it ???----------Salt water motor ??---------Is the shift shaft turning when you try and shift???
 
Lower unit has not been taken off, freshwater only. Haven't replaced the seals. Where is the shift shaft at on this motor?
Bassky
 
I am pretty sure it needs lower unit seals. I had water muffs on it last nite with the new lower unit oil and thought it would help. Still not engaging in forward or reverse. Drained all of the lower unit oil last nite and it came out like caramel milky looking. So I know I need to replace the lu seals. How can I check the shifting manually from up top of motor?
Bassky
 
Remove lower unit ---------------put vise-grip on shift shaft ( lightly ) then turn shift shaft and driveshaft , see what happens.
 
Could it be corroded together, locked up? Could the small amt of water, damage the gears or cause them to seize together?
Bassky:confused:
 
Not likely, but it is possible I suppose ----------------------Remove the lower unit and try to shift it by turning the shift shaft .----------------That is one way you will learn what is going on !!--------------Sorry, all you seem to be doing is looking and guessing. That will not get you results.
 
I had the same problem if you removed your out drive it would be because when you put it back on you got the gears stuck dont force it cause you can cause damage to the shift cable. Just lower your unit and look in the back where your drain hole for your boat is at, and you can see it from their just adjust it and you will be fine.
 
Lower unit hasn't been removed yet. Gonna happen tonite, maybe. What am I looking to adjust on the gears from the drain hole at the bottom? If I can adjust without taking lower unit off. What do you use to do the adjusting, screwdriver??
Dave
 
Remove the lower unit ----------------Turn the driveshaft in the normal direction and turn the shift shaft to see if it shifts.-----------------------Worry and ask about re-installing after that.------------------New waterpump impeller is required as well.---------------YOU CAN NOT ADJUST ANYTHING WITH A SCREWDRIVER ON THE LOWER UNIT !!
 
I didn/t think there was any kind of adjustment in a drain hole. I have the impeller kit. I hope it shifts manually or unlocks. Could the water be coming in from below the impeller at a seal there and is there anyway of knowing if this is where the water is coming into the lower unit? Anything I should be looking for?
Thanks racerone!
Bassky
 
Outboard shops pressure test lower units to find the leaks.--------------Certainly a pressure test is done after seals are replaced.
 
got the lower unit off. the shift shaft turns about 30 degrees both ways and it still isn't shifting from neutral to forward or reverse, manually. I guess my next steps would to take prop off and pull lower unit gears and shaft out. How do I disconnect shift shaft from gear box and is this the next step for removing gears and shaft???
Bassky
 
I'll bet the driveshaft is sheared inside the pinion gear--common problem. You'll have to pull it down to see.

Jeff
 
drive shaft or shift shaft? I took the prop off and loosened up some of the washers, seals (didn't remove them) and now it starts shifting manually. I turn the drive shaft and turn the shift shaft and it starts engaging. I now have forward and reverse gears. Any ideas why this happened?
Bassky
 
It is possible that the clutch dog was stuck from a bit of rust.----------------Take The lower unit apart for inspection and to change the oil seals / O-rings.
 
Thanks for all of the posts. I am going to look at a used lower unit tomorrow evening. Anything I should be aware of before I go? Also, how hard is it to put new seals kit in the lower unit. I got the seals kit yesterday and there are some gaskets that look like they may go under the water pump area and other stuff I am not sure where it goes and does the seals kit include like under the driveshaft and shift shaft areas? If I decide to pull the shaft/gears out do I need to disconnect any of the shafts or anything I am not aware of or just pull it out?
Bassky
 
Pull the drain plug and look CAREFULLY at what comes out. Turn the driveshaft and feel if it's smooth. Be sure the plunger (top of driveshaft) is there and working (springing back).

Changing the seals requires a total dissassembly of the LU, and that means a few special tools. Unless you've done it before--and have the tools--I would not attempt it.

Jeff (dozens of LUs rebuilt to date)
 
Is the " used " unit in tip top shape ???---------------If not resealed , guaranteed to be good , then you will need to reseal it.----------------------Today is a good day to learn how to do it yourself and it is not all that hard to do.
 
Bassky,perhaps you should visit U-tube and search for -----------Mercury lower unit --repair / reseal / overhaul etc---------------There are lots of folks showing their skills on video and encourage you to give it a shot.---------------------No such thing as ----" can't be done in this day and age "
 
Racerone,
Thanks I have gone to utube and reviewed lower unit repair. Definitely need some special tools. I have done lower unit repair on an older evinrude years ago. I will go through the used lower unit and driveshaft making sure it works and is smooth and not grinding and checking the lower unit oil.
Bassky
 
A spring-loaded button in the center of the drive shaft. Some models of LUs have them, some don't, but IF it has one, the plunger must work.

Jeff
 
So called special tools are used as " shop time savers "-----------they are not always needed to do the job at home ----------------If you do not want to learn how to do the job then you are beat before you start !!
 
I'd like to see someone get that plastic nut that holds the prop shaft assembly in without a special tool. If it wants to be stubborn, a new one will be required for certain!

Jeff
 
I don't believe mine has one. Is located below the waterpump? or where it goes into the top, engine? I bought the lower unit. The fella said it had been sitting for 6-7 years. I checked the lower unit oil a bit dirty but not milky, a good sign and the shafts and shifting seemed to work good. I am going to replace the water pump tonite and give her a shot. He said if it didn't work out he would refund my money. Thank you for all of your help. Stay tuned for the results.
Bassky
 
Well the lower unit didn't work out. It only had forward gear and would not shift out of forward. No reverse, no neutral. Put new oil in lower unit and replaced waterpump. The impeller was really hard to get it in the housing, is this normal? I put a light coating of grease in the housing and on the blades of the impeller. I got it in but it was tight. When I turn the prop shaft by hand it makes a loud click. I am confused how the shifting works. I know how the clutch dog has a built in spring and moves to engage the gears. But what makes the clutch dog move, how does the shift shaft make it move? The shift shaft moves left and right about 30 degrees. I have a clymers manual but it doesn't show this linkage in schematics. I am back to square one. I was able to pull prop shaft and gears out. My clutchdog and gears where they mesh are worn and need to be replaced. The clutch dog was seized. Got it unseized and was springing back and forth. Put it all back together hoping this would work but when I shifted from neutral to forward or reverse, no engaging neutral only. Any suggestions? I am returning the lowerunit to the seller this week.
Bassky
 
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