Removing lower unit on Johnson 9.5 1970

[Ken67]

Hey all I am new to these forums and have a question. I have picked up a 1970 Johnson 9r70c 9.5hp motor and want to replace to impeller/water pump. When attempting to remove the lower I have taken out the 4 screws and disconnected the shift rod. Now in the manual it says there are 4 different ways to drop the lower unit and I cannot figure out which method I need. I have tried to rotate the flywheel clockwise to line up the pin but have had no success doing this. So i guess my question is do I need to remove the powerhead to disconnect the driveshaft? I am just trying to figure out the simplest way to replace the impeller. Thanks in advance!

 

[F_R]

Re: Removing lower unit on Johnson 9.5 1970

That instruction does not apply to the 9.5, only to 6hp models.
Place shift in forward, and with the four screws out, lower the gearcase about 3/4", and inside you will see the brass shift rod coupler. Remove the lower screw from it, then lower the gearcase down and away. That's all there is to it.

 

[Ken67]

Re: Removing lower unit on Johnson 9.5 1970

Thanks for the response F_R. I have removed the four bolts and disconnected the shift rod and the lower unit won't budge. I have read on other threads that when sometimes this means that the drive shaft is stuck in the powerhead. Do you think this is the case? If so do I just need to apply lubricant and slowly try to get the drive shaft out? Thanks

 

[F_R]

Re: Removing lower unit on Johnson 9.5 1970

That is a possibility. But it must have come down a bit or you couldn't have disconnected the shift rod, right? If that is the case, yes it sounds like a drive shaft splines problem. There is no easy answer to that. Well, yes there is. "Lotsa Luck". There really isn't any way to get at it to do anything about it except go ahead and force the dang thing off. It probably will pull the impeller drive pin through the top of the water pump, leaving the drive shaft stuck in the crankshaft. Then you can turn it upside down and try drizzeling some of your favorite rust dissolving potion down the shaft in hopes it will free up the splines.

It probably won't.

Removing the powerhead to get at the area is a daunting job for a novice.

 

[Ken67]

Re: Removing lower unit on Johnson 9.5 1970

Thanks for the response. I guess i will try to work the thing off and see what happens. Luckily i got the motor for free so no real loss other than having to get another motor if it doesn't work. Worst case scenario I will attempt to remove the powerhead and see what happens. It is a good learning opportunity for my first motor repair.

 

[F_R]

Re: Removing lower unit on Johnson 9.5 1970

. It is a good learning opportunity for my first motor repair.

You got that right. You couldn't have picked a more challenging one. Well, maybe a 1960 Scott/McCulloch/Elgin 7.5hp.

 

[F_R]

Re: Removing lower unit on Johnson 9.5 1970

BTW, speaking of learning opportunity, all that grief was caused by the last guy leaving a ten cent o-ring out. What a shame.

 

[Ken67]

Re: Removing lower unit on Johnson 9.5 1970

Well good news is I got the lower unit out. I don't think I did any damage prying it loose. The drive shaft came out with the lower unit as well. It looks like the splines on the top of the shaft are extremely rusted, probably hasn't been removed in a long time. Removed water pump housing and the impeller is in a thousand pieces. Once again probably not replaced in entirely too long. So now I am going to replace the impeller, seals, and grommet. Then hopefully I can get the lower unit to go back into the powerhead. Now should i replace the lower unit oil while the lower unit is off or does that really matter? Thanks for all the help F_R

 

[nwcove]

Re: Removing lower unit on Johnson 9.5 1970

is the o-ring below the splines still there?

 

[F_R]

Re: Removing lower unit on Johnson 9.5 1970

You got lucky. Make sure that a new o-ring is in place and smear some waterproof grease on the splines. It would be nice also if you could get something up in there to clean the rust out of the crank splines (extended wire brush??)

Sure, you should at least check the oil, and replace it if in any doubt.

 

[oldcatamount]

Re: Removing lower unit on Johnson 9.5 1970

Actually, it's a pretty safe bet the lower unit seals need to be replaced given the condition of the impeller and driveshaft. It would save you in the long run.

 

[Ken67]

Re: Removing lower unit on Johnson 9.5 1970

Thanks for all the answers guys. NWCOVE is the o-ring you are talking about going to be directly below the splines at the top of the driveshaft? If so there is not one there. It looks like the o-ring directly under the splines is still at the top of the driveshaft tube. Any suggestions on how to get that out without removing the powerhead or am I out of luck? I will take the advice and replace the lower unit oil and I am going to check the lower unit gasket because like you said this motor doesn't look like it has been worked on in awhile.

 

[boobie]

Re: Removing lower unit on Johnson 9.5 1970

Get an old metal coat hanger, cut it and straighten it out and put a small bend on one end. Then use that to fish out the old o-ring.

 

[bonzoscott]

Re: Removing lower unit on Johnson 9.5 1970

Just an idea I had, where there's a will there is a way. I have several wire brushes in my shop - different varieties. If you can find one like used to clean the inside of a a battery terminal - kinda like a bottle brush - and secure it to a dowel or something, put some grease on the bristles.. You can clean them splines in the crank. Push it in and out. I wouldn't try and rotate.