Changing water pump Johnson RDS-22 40HP

[gunplumber7]

I'm trying to change my impellor but my manual ( Johnson Service technician manual) has me confused. Can I just drop the lower end and change the pump without removing the power head and breaking down into major components? How do I drop the lower unit? I have removed the extention bolts (for long shaft) as well as the actual lower unit bolts and have removed the 2 screws connecting the shift cable inside. Now what? Anyone have a manual which breaks it down "Barney Style" that they can email me the pages I need, or anyone that can simply guide me through the process? Anyhelp is appreciated. I am searching through the threads too but want to get this done and have it ready for the weekend. Thanks again. Jerry

 

[lindy46]

Re: Changing water pump Johnson RDS-22 40HP

Did you remove the rear exhaust housing cover? There is a large vertical bolt at the very back of the engine that goes through from the top, and that also has to be removed to drop the lower unit. That bolt is behind the exhaust cover. No need to remove the powerhead.

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

I've removed the long bolt as well as the short ones surrounding the housiing and extension. Exhaust cover is off. I saw what appeared to be the shift linkage (inside by water pump) with 2 small screws. I removed them too. Now I have the water tubes and I guess the drive shaft holding it up? Thanks for your response.

 

[lindy46]

Re: Changing water pump Johnson RDS-22 40HP

Sounds like the upper driveshaft spline is rusted in the crank and holding it on. If possible to get to the driveshaft with some penetrating oil - tilt the foot of motor up so oil runs to the splines on the shaft and let it soak a while. Even then, it may take some force to get it off. I'll bet the O-ring at the top of the driveshaft is missing!

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

So with the bolts removed, everything should just drop down, no other connections to look for? Can I tap it down with a rubber mallet?

 

[lindy46]

Re: Changing water pump Johnson RDS-22 40HP

The only thing that holds the L/U on are the bolts and the shift rod. If all the bolts are removed and the shift rod is disconnected at the coupler (under the plate on the side of the leg), the L/U should drop down. You can try a rubber mallet, but if the driveshaft splines are rusted into the crank, it may be difficult without getting some penetrating oil up there. But give it a try.

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

Thanks for the help. I'm going out to check now. The mallet will come after the oil if needed. Jerry

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

I just took of the rectangle cover on the side and and the weird shaped cover under that. I am now looking at the brass coupler with two small bolts. Do I need to remove the 2 bolts and then pull down?

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

Found the picture of the connector under a different section of the manual. said to remove bottom screw which I did and after a couple trys downward she popped right apart. Thanks for the help. Now That that's done it's time to go to sllep and finish the rest when I get up. You've been a big help.

 

[lindy46]

Re: Changing water pump Johnson RDS-22 40HP

Yup - I thought you had already disconnected the shift rod. Be careful when putting that back together. The shift rod has to be positioned so the indent at the top of the rod can be seen through the bolt hole in the coupler. The bolt must pass through that indent. If it's off a bit, you'll strip the bolt threads and the motor won't shift correctly. Glad it wasn't a rusted driveshaft!

 

[gunplumber7]

Re: Changing water pump Johnson RDS-22 40HP

What I thought was shift linkage was actually the tube connection. Couldn't tell as I could only get enough space to insert the driver and remove the screws. Now that it's off and I've had a chance to look at it, I find that I've got a boggled tube gasket which I'll try to pick up tomorrow. I noticed the cover to the pump at the junction of the tubes has 2(?) small holes about
1/4" apart where the tubes bolt on. Bottom hole I pushed a wire through. Top has hole in gasket, and hole in tube bracket, but no hole in pump cap. Is there supposed to be two small holes in the cap? Is there supposed to be a gasket between the pump and the plate where it bolts on or is it just metal to metal? Do I need to polish the inside of the pump? Thanks again. Jerry