40 HP NS-40D Water pump replacement

[Tim Frank]

Winterised the motor yesterday, and have the W Pump kit and was going to do this too, but had some problem with the manual's instructions.

1) To remove the spring pin can you just "tap" it out with a pin punch of the right diameter, and how much force can you use if it is stubborn?...or do they almost always come out easily?

2) I must be missing something in the manual, because it gives details for models 60 and above, but not 40.
There are 6 "external" mounting bolts on my 40 just as the manual shows for the other models, but on the higher HP models it shows an "internal' bolt that is accessed by removing what the manual calls the "gearcase plate or sub water strainer" which in the illustration appears to be held on by three screws.

On my 40 HP, there are no screws on that component, which seems to be plastic.
Since it looks like the kind of part that would break easily, and perhaps not be available without a long ordering delay, I stopped the job and thought I would ask in here to make sure that I didn't %^$$#-up something.

Does the 40 HP even have that hidden bolt, and if so, how does that plastic cover come off?

 

[TOHATSU GURU]

Re: 40 HP NS-40D Water pump replacement

1) Yes and back up the other side of the coupler with....Anything other than a loaf of bread. Actually you could use a loaf of braed if it was stale eough.

2) Get the correct manual and there are only the six visible bolts.

 

[Tim Frank]

Re: 40 HP NS-40D Water pump replacement

1) Yes and back up the other side of the coupler with....Anything other than a loaf of bread. Actually you could use a loaf of braed if it was stale eough.

Perfect, thanks. Looks like a job best done with 3 hands....

2) Get the correct manual and there are only the six visible bolts.

Is there a specific manual just for 40 HP?
I asked in here and ended up with the "3&4 CYLINDER MODELS SERVICE MANUAL" from Tohatsu Outboards....PN 003-21036-1.
I referred to section 6, Gearcase and page 6-10 gearcase removal.
It really only gives details for the larger motors.

Did I get the wrong manual, or am I just missing the instructions for 40 HP, or do you have to infer more than I had thought?

 

[TOHATSU GURU]

Re: 40 HP NS-40D Water pump replacement

Right manual. They anticipate that you are using the free parts manual (to fill in the gaps) along with the service manual. That particular service manual is actually pretty good compared to what else is on the market. I think you found one of the few ambiguous parts of it You can download a free parts manual from www.internetoutboards.com

 

[Tim Frank]

Re: 40 HP NS-40D Water pump replacement

Thanks Elvin.
If I have it straight,:
1) The manual I have is correct.
2) The 40 ONLY has the 6 bolts, no hidden bolt. If so, I am, good to go.

 

[pvanv]

Re: 40 HP NS-40D Water pump replacement

Yes, that's correct. Also, Tohatsu sells 2 tools to make the roll pin removal/installation easier.

"Handy tool for removing shift rod spring pins when removing lower unit. Punch end is designed to self center in the spring pin for easy removal. Fits 3.5B to 90A 2-strokes, 8hp-30hp 4-strokes, and all TLDI models." Part # 345722270M List Price (MSRP): $14.97

"Handy tool for installing shift rod spring pins when installing lower unit. Tool end is designed to hold the spring pin for easy installation. Fits 3.5B to 90A 2-strokes, 8hp-30hp 4-strokes, and all TLDI models." Part # 345722280M List Price (MSRP): $14.97

 

[Tim Frank]

Re: 40 HP NS-40D Water pump replacement

Pulled the L/U with no trouble. Thanks.
I have all winter to R & R the water pump with the kit that I have, but might as well get it done.

So that I am ready to reinstall the L/U in the spring, I am wondering about the seal for the water tube.
It is not in the WP kit which I ordered at the same time as the service manual so I had not considered that seal or even whether it was included in the kit.

Should this seal be replaced EVERY time you do this water pump service, or can you just assess the condition and reuse if it seems ok?

 

[pvanv]

Re: 40 HP NS-40D Water pump replacement

There are actually 4 parts that comprise that seal.
3C8650140M RUBBER SEAL $2.28
346652040M LOCK RUBBER, WATER PIPE $1.97
345652050M COLLAR $1.40
345652060M UPPER SEAL RUBBER, WATER PIPE $1.77

We only replace them as needed. They're not subject to friction/wear, so it's mostly dry rot that causes deterioration. They last many years.

 

[Tim Frank]

Re: 40 HP NS-40D Water pump replacement

Thanks for the responses....I may get this done yet... ....bit by bit..

Quite different from OMC design, but IMO nice engineering.

Now that I have it all apart, a few more items I wonder about replacement...

1) the lower W/P plate, has large o-ring that seals against the bore in L/U housing; that can't be too many $$$, so should that not be changed since it is so easy?

2) drive shaft seal in same plate...seems trickier, is that one that you might change , say, every 2nd impeller replacement?

3) The anaerobic sealer that they specify, is that just a Loctite type product or does Nissan have their own proprietary stuff? Would Permatec work?

4) The metal liner....how do you get that out of the housing in a non-damaging fashion?

5) The kit that I purchased includes 4 new W/P bolts. Why do they need to be replaced?

Thanks.

 

[pvanv]

Re: 40 HP NS-40D Water pump replacement

We usually do those seals when doing a complete re-seal of the LU. But, since you have it apart, you would want... 345650150M O-RING $2.53, and qty (2) C8602230M OIL SEAL $6.20

Blue LocTite works OK, or Permatex Thread Sealer.

You can warm up the WP upper housing with a heat lamp to expand it a couple of thousandths. Sometimes the stainless cup is pretty stuck, and has to be pulled out with vise-grips after you get a lip of it partially exposed.

Some older salt water units have severely corroded bolts. If yours are OK, you could re-use them... but you already have the new ones...