Water pump and the dreaded spline alignment

[powrguy]

I bought the waterpump rebuild kit for my Mariner 135HP 1988 model, and found that I wound up with a handful of spare parts. On dis-assembly, there were only the two gaskets for above and below the faceplate, the faceplate, the water tube guide, and the centrifugal slinger that I replaced. All those O-rings that came with it (I believe if you change the waterpump base, you would need those?) were left over. My old impeller was still in very good shape, but I changed it and the cover housing anyway. Are those o-rings for the base that I didn't remove?

Also, I'm in the dreaded "can't line up and fully install the lower unit" mode, as evidentally, I don't have the driveshaft splines lined up or something. I was really careful not to rotate the driveshaft while I did the pump, but maybe it moved a small amount to mess up the alignment.

I've read the numerous other threads about using neutral, using F or R, and am going to try the N install, with a helper rotating the flywheel slightly to slide it up fully. My question is on the shifter shaft coupling; as it is free to wave around a bit in the mid-housing, and you have to use your third hand to ease it into position then to allow the splines of the male/female parts to connect, right?


thanks

 

[Dukedog]

Re: Water pump and the dreaded spline alignment

Yes, O rings for tha base.
Stabing is really for 2 people unless you invest in a remote start button. Makes life a lot easier. Not just for tha lower unit install but several other things when workin' on your own stuff.

This is tha way I was taught ta do it...........
I use tha Neut. position. Other folks got their way. Get tha case up far enough ta start tha water guide tube then someone has ta "bump" tha starter(be sure ta pull tha kill switch) or turn tha flywheel while you keep pressure on tha case. Tha new impeller will keep tha driveshaft from turning. It will line up and go in. Don't let it fall from this position. Next barely start tha nut in front and tha 2 nuts on tha side. Take tha pressure off and let it fall back to tha nuts. Now you can take a break. Tha nuts will keep it from dropping out of tha motor and allow you to push up and align tha shift shaft without it dropping to tha floor. Put a socket and ratchet on tha front nut before you start pushing up to align tha shaft. Once tha shaft is in you can tighten tha front nut enough with one hand to keep it from dropping.

GL............D

 

[powrguy]

Re: Water pump and the dreaded spline alignment

Yes, O rings for tha base.
Stabing is really for 2 people unless you invest in a remote start button. Makes life a lot easier. Not just for tha lower unit install but several other things when workin' on your own stuff.

This is tha way I was taught ta do it...........
I use tha Neut. position. Other folks got their way. Get tha case up far enough ta start tha water guide tube then someone has ta "bump" tha starter(be sure ta pull tha kill switch) or turn tha flywheel while you keep pressure on tha case. Tha new impeller will keep tha driveshaft from turning. It will line up and go in. Don't let it fall from this position. Next barely start tha nut in front and tha 2 nuts on tha side. Take tha pressure off and let it fall back to tha nuts. Now you can take a break. Tha nuts will keep it from dropping out of tha motor and allow you to push up and align tha shift shaft without it dropping to tha floor. Put a socket and ratchet on tha front nut before you start pushing up to align tha shaft. Once tha shaft is in you can tighten tha front nut enough with one hand to keep it from dropping.

GL............D

That's pretty much how I thought to do it, but just manually bumping the flywheel, with no battery power used. I can't see the water tube mating, so how does that part work? The point where the shift shaft is NOT engaged is near-exactly when the driveshaft spline enters, it feels like, so I see what you're saying about just barely engaging the splines, and then moving the shift shaft into position. How do I know the water tube has mated up with the pump extension tube?


thanks

 

[Chris1956]

Re: Water pump and the dreaded spline alignment

You need to install the white plastic water tube into the waterpump outlet. Now stick the copper water tube into the white plastic one, as you install the gearcase, to make sure it is aligned properly.

 

[powrguy]

Re: Water pump and the dreaded spline alignment

Yeah; I've got the white plastic tube in the water pump, and the oil slinger rubber ring installed on the pump. I just have to get the copper tube into the white plastic tube as I am sliding the lower unit back into the midsection, right? Can I see and/or feel that copper pipe going into the tube?

thanks

 

[Chris1956]

Re: Water pump and the dreaded spline alignment

Correct, you will need to grab the copper tube and guide it into the white plastic tube.

 

[powrguy]

Re: Water pump and the dreaded spline alignment

My lower unit is installed. I used the neutral-with-a-helper method, with the helper SLIGHTLY rotating the flywheel manually as I kept re-testing for engagement of the splines, just dropping the lower unit about 1/8" or so to make sure the driveshaft wasn't rotated with the motor. On the install, FIRST, the water tube was checked to see it was engaging into the white plastic tube in the pump. Then, the driveshaft spline was accomplished, then dropped the lower unit just enough to work the mating of the shift shaft splines into the lower unit. Then, it slid home without a problem. I think the neutral method is probably the best to avoid a shifter-position misalignment by one tooth. Worked for me.

 

[powrguy]

Re: Water pump and the dreaded spline alignment

Yes, O rings for tha base.
Stabing is really for 2 people unless you invest in a remote start button. Makes life a lot easier. Not just for tha lower unit install but several other things when workin' on your own stuff.

This is tha way I was taught ta do it...........
I use tha Neut. position. Other folks got their way. Get tha case up far enough ta start tha water guide tube then someone has ta "bump" tha starter(be sure ta pull tha kill switch) or turn tha flywheel while you keep pressure on tha case. Tha new impeller will keep tha driveshaft from turning. It will line up and go in. Don't let it fall from this position. Next barely start tha nut in front and tha 2 nuts on tha side. Take tha pressure off and let it fall back to tha nuts. Now you can take a break. Tha nuts will keep it from dropping out of tha motor and allow you to push up and align tha shift shaft without it dropping to tha floor. Put a socket and ratchet on tha front nut before you start pushing up to align tha shaft. Once tha shaft is in you can tighten tha front nut enough with one hand to keep it from dropping.

GL............D

I did it manually, with a helper, and your instruction worked out perfectly. The shifter shaft is the tricky engagement, as it is floating and not held still in line with the stub shaft. However, with the helper, it worked out.

 

[gman1001]

Re: Water pump and the dreaded spline alignment

Good title for this thread!

I've followed the tricks listed here with NO luck.

I have a 1988 Merc 115 6CYL. Last chance here before I haul the whole thing to dealer. (ugh)

I believe I have the splines lined up using the flywheel nuetral method.

With someone holding onto the shift shaft with needlenose (from the outside of the motor leg) trying to align the shift shaft is just not working.

I have about 1/2 inch gap left and I'm pretty sure the shift shaft is just not lighning up.

My other issue is this: The white plastic water pump connecting tube - the one that sits IN the water pump housing and then mates up with the copper tube in the motor leg is coming out of the water pump housing and riding up over the copper pipe! I know this is because in part I'm pulling the motor in / out, in / out trying to synch the shift shaft... But whats to stop this from happening while the motor is running! I would think this would prevent the motor from receiving water to cool it!

Any other magic hints if I just cant get this lower unit installed?

BTW, there is nothing blocking the driveshaft up within the motor leg...

Tx in advance!

 

[trendsetter240]

Re: Water pump and the dreaded spline alignment

Why not pull the leg out, pull up on the shift rod and turn the prop by hand to put it into reverse. Then install the leg, when the driveshaft meets the crank turn the prop back and forth by hand until the splines mesh.

Unless there is some reason for being in neutral for this motor that I am not aware of..

Also I think you'd be nuts to try and bump the motor over with the starter while installing a leg.

 

[gman1001]

Re: Water pump and the dreaded spline alignment

Forgot to mention, all spark plugs removed...

What do you mean pull up on the shift rod? The rod on the lower unit or the rod linkage coming down from the motor head?

Does anyone know what direction turning the shift rod on the lower unit is FWD or RERVERSE?

 

[Chris1956]

Re: Water pump and the dreaded spline alignment

Looking down from the top of the gearcase, turning CW is going to forward.

 

[gman1001]

Re: Water pump and the dreaded spline alignment

Ok, I'll try the FWD method tonight when I'm home from work... Any thoughts on putting the boat in FWD vs. REVERSE in terms of ease of install?

I'm guessing the Shift control HAS to match whatever gear the lower unit is in while installing or else I'm in huge trouble correct?

 

[trendsetter240]

Re: Water pump and the dreaded spline alignment

Ok, I'll try the FWD method tonight when I'm home from work... Any thoughts on putting the boat in FWD vs. REVERSE in terms of ease of install?

I'm guessing the Shift control HAS to match whatever gear the lower unit is in while installing or else I'm in huge trouble correct?

Yes, Chris1956 is right of course. It's the j/e that shift up/down.

Yes, also put the shift control into FWD before inserting the leg. The only reason I put them in gear is so that you can rotate the prop by hand to line up the drive shaft to the crankshaft in one shot.

Reverse should be the same..I always put my Mariner in FWD simply because it had to be in FWD to tilt up.

 

[gunner1]

Re: Water pump and the dreaded spline alignment

Something I tried that helped alot was to look at the driveshaft when you take the waterpump off. When you rotate the shaft to get the impeller installed under the housing, make sure you stop in the same orientation that the shaft was whne you removed it.

 

[gman1001]

Re: Water pump and the dreaded spline alignment

UPDATE: I feel like a fool but thought this info would be helpful to others.

I was assuming the lower unit would sit all the way home while pushing it into place, assuming the spines where lined up. The 1/4 yo 1/2 remaining for me (and causing me the headaches) was either the water pickup tub resting against the rubber gasket or the exhaust jacket on the lower leg resting against the rubber gasket in the lower unit.

Once I applied gentle pressure by turning down the nuts on the lower unit, I felt a slight 'pop' or 'give' and the unit seated in its final spot nicely.

Job finished. (phew)

Tx all.