re-fitting water pump housing onto driveshaft?

[sweetmarie]

I'll start by wishing those that are into the new year already a prosperous and Happy New Year.

I'm trying to re-fit the water pump assembly back onto the drive shaft of my 1981 15 hp Johnson. Taking it apart was easy (although I lost the key for the impeller when it flew off). Now I can't seem to fit it all together. I've got the pump assembled and bolted on the bottom end but how can I slide it onto the shaft and keep the key in the slot and on the shaft?
Do I have to disconnect the drive shaft at the top?

I'm not a mechanic by trade as you can tell, thanks for some input.

SM

 

[Vic.S]

Re: re-fitting water pump housing onto driveshaft?

Yes pull the drive shaft from the crankshaft (not easy sometimes). Refit it to the gearcase (take care not to damage the seals ... Now is a wise time to change them anyway) then reassemble the pump by sliding the parts down the shaft.

Lightly grease the splines on the top of the drive shaft to prevent it seizing/rusting into the crankshaft again.

See the item on the "Engine Frequently asked questions" board about 15hp and 9.9hp engines for just about every thing you'll ever need to know.


Has the impeller key damaged the pump casing or are you replacing it anyway? It should have held the shaft into the Lu and allowed it to pull out of the crankshaft when you dismantled it!

 

[bktheking]

Re: re-fitting water pump housing onto driveshaft?

I'll start by wishing those that are into the new year already a prosperous and Happy New Year.

I'm trying to re-fit the water pump assembly back onto the drive shaft of my 1981 15 hp Johnson. Taking it apart was easy (although I lost the key for the impeller when it flew off). Now I can't seem to fit it all together. I've got the pump assembled and bolted on the bottom end but how can I slide it onto the shaft and keep the key in the slot and on the shaft?
Do I have to disconnect the drive shaft at the top?

I'm not a mechanic by trade as you can tell, thanks for some input.

SM

Sounds like you did it bass ackwards. You don't need to pull the shaft out to do this. Remove the o ring at the top of the shaft and slide the pump housing and impeller off. Put some grease on the key for the impeller and stick it to the driveshaft to hold it in place. Slide the new impeller down the shaft and line with the key. Put some grease around the inside of the pump housing around the metal diameter sides. Slide the housing down the shaft until it gets to the impeller. Now turn the drive shaft by hand while pushing downward on the housing, the impeller blades will eventually bend and seat inside the cup, now bolt the housing down. Replace the oring at the top of the shaft.

 

[Vic.S]

Re: re-fitting water pump housing onto driveshaft?

Sounds like you did it bass ackwards. You don't need to pull the shaft out to do this. Remove the o ring at the top of the shaft and slide the pump housing and impeller off.

Hes got the drive shaft stuck in the crankshaft !! Got to get that out from there ! It should have come out from there in the first place

 

[sweetmarie]

Re: re-fitting water pump housing onto driveshaft?

Yes pull the drive shaft from the crankshaft (not easy sometimes). Refit it to the gearcase (take care not to damage the seals ... Now is a wise time to change them anyway) then reassemble the pump by sliding the parts down the shaft.

Lightly grease the splines on the top of the drive shaft to prevent it seizing/rusting into the crankshaft again.

See the item on the "Engine Frequently asked questions" board about 15hp and 9.9hp engines for just about every thing you'll ever need to know.


Has the impeller key damaged the pump casing or are you replacing it anyway? It should have held the shaft into the Lu and allowed it to pull out of the crankshaft when you dismantled it!

I pulled the pump housing straight off the shaft and doesn't appear that I damaged the top of the housing seal or anything else inside the housing. Nor did I realize that the shaft was splined into the crankshaft although it did cross my mind while trying to troubleshoot how to assemble it. Hopefully the shaft will come apart easily, any "easy" way to pull them apart? Meanwhile I'll do some reading in the "frequently asked questions" section. Thanks to all of you for your help, appreciate it as usual, this site is awesome. I've told a lot of people about this site.

 

[bktheking]

Re: re-fitting water pump housing onto driveshaft?

Hes got the drive shaft stuck in the crankshaft !! Got to get that out from there ! It should have come out from there in the first place

Yes it should have, a little more work involved now, sorry vic, didn't see thay part

 

[Vic.S]

Re: re-fitting water pump housing onto driveshaft?

any "easy" way to pull them apart?

Turn up side down and run some of your favorite release fluid down the shaft to soak into the joint with the crankshaft. Then hope a bit of brute force will do the trick.

 

[sweetmarie]

Re: re-fitting water pump housing onto driveshaft?

Turn up side down and run some of your favorite release fluid down the shaft to soak into the joint with the crankshaft. Then hope a bit of brute force will do the trick.

Good idea, why didn't I think of that?? Release fluid meaning we can't use name brands on the site I would guess but I know what you mean. Like some "W"onder if "D"an is "40"?
How to pull on the drive shaft, any secret weapon to get a good grip on it?

Or what if I re-insert the drive shaft back into the lower unit (removing the pump housing first) and insert the screw on the outside of the foot for the shifter, will that hold the bottom of the drive shaft so it will be solid enough to pull the drive shaft out of the crankshaft? That's what I should have done in the first place, right? Of course I will run the juice down the drive shaft anyway.

 

[bktheking]

Re: re-fitting water pump housing onto driveshaft?

?

Or what if I re-insert the drive shaft back into the lower unit (removing the pump housing first) and insert the screw on the outside of the foot for the shifter, will that hold the bottom of the drive shaft so it will be solid enough to pull the drive shaft out of the crankshaft? That's what I should have done in the first place, right? Of course I will run the juice down the drive shaft anyway.

Not sure what you mean, what screw? The screw holds the shift yoke, not the drive shaft, the shaft isn't held in by anything. Put the shaft in a vice with 2 blocks of wood and try tapping the lower unit with a block and a dead blow hammer. You may have better luck pulling the power head to do this, not a big job to pull the powerhead. Try it attached first, soak it with PB BLASTER and see if it comes out.

 

[sweetmarie]

Re: re-fitting water pump housing onto driveshaft?

Not sure what you mean, what screw? The screw holds the shift yoke, not the drive shaft, the shaft isn't held in by anything. Put the shaft in a vice with 2 blocks of wood and try tapping the lower unit with a block and a dead blow hammer. You may have better luck pulling the power head to do this, not a big job to pull the powerhead. Try it attached first, soak it with PB BLASTER and see if it comes out.

Thanks, that's why I come here. So the screw acts as a pivot point for the shift yoke I gather. PB Blaster, never heard of it but I found out where I can get it and boy, the reviews are amazing. Can't believe I've never heard of it. They sure don't advertise much.
I just finished pouring Jig-a-Loo down the shaft, that's all I had tonight. Can't do any harm. I'll be trying to reef on it tomorrow after work. I may hang it upside down about an inch from a thick cushion, attached only by the drive shaft with a thin sling and tap lightly at the break apart with a block as you suggested.

 

[Vic.S]

Re: re-fitting water pump housing onto driveshaft?

Release fluid meaning we can't use name brands on the site I would guess

No problems mentioning specific products but I dont know what part of the world you are in.

PB Blaster seems to be the most highly regarded in N America but never seen it in the Uk. Plus Gas is probably the best over here.

WD 40 is primarily a water displacing fluid... hence WD.

Don't know if you can get a set of Molegrips / Vise grips (or what ever you call locking pliers where you are) on to the end of the shaft without damaging a bit you wont want damaged and tapping those with a hammer.

You are going to have to be carefull about putting that pivot pin back in! You may have a job to get the bit inside to line up. Jiggling things about with a measure of ingenuity I beleive ususally succeeds but if the worst comes to the worst you will have to dismantle the gearcase !

 

[sweetmarie]

Re: re-fitting water pump housing onto driveshaft?

No problems mentioning specific products but I dont know what part of the world you are in.

PB Blaster seems to be the most highly regarded in N America but never seen it in the Uk. Plus Gas is probably the best over here.

WD 40 is primarily a water displacing fluid... hence WD.

Don't know if you can get a set of Molegrips / Vise grips (or what ever you call locking pliers where you are) on to the end of the shaft without damaging a bit you wont want damaged and tapping those with a hammer.

You are going to have to be carefull about putting that pivot pin back in! You may have a job to get the bit inside to line up. Jiggling things about with a measure of ingenuity I beleive ususally succeeds but if the worst comes to the worst you will have to dismantle the gearcase !

I'm in Canada. WD 40, Liquid Wrench and LPS are what I've seen mostly here for loosening stubborn parts. PB Blaster is available 45 minutes away but not in my home town.


I want to make a "puller". I already took a large nut, drilled and tapped two 1/4" holes on the side of the nut so I can thread two bolts to lock onto the shaft. Then I'll take 3.5" x 6" - 1/4'' steel plate, make a hole in the center for the shaft, drill 6 holes so I can put the screws through the plate and screw them to the lower unit ( with the locked nut secured on top of the plate). Each bolt around the steel plate will have a nut (under the plate) which I will turn to lift the steel plate against the nut that's bolted to the shaft and hopefully pull the driveshaft out the crankshaft.

What do you think?

 

[samo_ott]

Re: re-fitting water pump housing onto driveshaft?

You Canadians always trying to make the job harder! That sounds like a lotta work. I just clamp on vice grips real tight somewhere where there's no seal and just hammer on it. After you get some pb blaster up there. I think they sell it at Canadian Tire although I bought mine in Florida last year... WD40 wont really do it although it's better than nothing and probably better than jig a loo! Isn't that a teflon or silicon lubricant or something like that?

 

[Vic.S]

Re: re-fitting water pump housing onto driveshaft?

Maybe tapping the end of the shaft a couple of times will help break it free. Gentle taps with big hammer rather than belting with a little hammer. Protect the end of the shaft with a bit of brass or copper though. Don't go mad either you don't want to bust the crankshaft!

Googled for Jig a loo. Silicone based spray suitable for zips on SWMBO's dress etc

 

[sweetmarie]

Job Complete

Job Complete

Maybe tapping the end of the shaft a couple of times will help break it free. Gentle taps with big hammer rather than belting with a little hammer. Protect the end of the shaft with a bit of brass or copper though. Don't go mad either you don't want to bust the crankshaft!

Googled for Jig a loo. Silicone based spray suitable for zips on SWMBO's dress etc

All done!!! My homemade puller worked great, didn't need any PB Blaster but you can bet I'll get a couple cans next time I'm in the city. I grooved on the drive shaft where there's no seal or bearings, attached my nut with the two bolts on the side to the drive shaft and slowly lifted the steel plate fastened to the lower unit(pre-drilled from a template I made) against the nut, and the shaft popped out.

Thanks Vic.s and everyone for your time and suggestions.