Nissan 4 stroke 9.8A drive shaft assembly

[Rick Russell]

Trying to reinstall the driveshaft after replacing the gasket to my lower pump case on my Nissan 4 stroke 9.8A and did not do a very good job of remebering what the order of parts were on the shaft (note to self, take pictures next time). Here are the items I am concerned about:

1. There was a very flat ring, which could be the gap liner when you look at the parts manual.
2. A small sleeve about 3/4 inch long. I hope this is not the needle bearing! Which, I don't think it is, because it took no effort to take out ( the SELOC manual made it seem like it was a big deal to remove this with all sorts of special tools). It just slide off with the drive shaft, but I can't think of what else it could be.
3. Small washer.

The parts manual is in conflict with the SELOC manual, which is why I am here. The SELOC manual also has some holes, which is fair or the manuafacturer put some extra parts in my outboard that would not normally go in there.

The order that I placed the parts into the driveshaft assembly is

1. Small sleeve
2. Large sleeve (about 6 inches long)
3. Small washer
4. The ball bearing (was still attached to the shaft, I never removed this)
5. Gap liner
6. oil seal (never actually removed this from the lower pump case )
7. Pump case.

Any comments?

I've seen some great posts on this site, so I'm hoping to benefit from the same knowledge.

Thanks folks!

 

[pvanv]

Re: Nissan 4 stroke 9.8A drive shaft assembly

First, you should find someone you don't like, and give them that aftermarket manual. The best-written Factory service manual for the 4-stroke NSF9.8 is Part# 003N210561, $27.58... But that is written for the 9.8A3, which will have some slight differences from an early 9.8A, particularly information about the paint colors, anode, and remote steering linkages. The earlier 9.8A Factory service manual, which suffers a bit from language translation, Part# 003N210561, $27.58, is OK, and will show the earlier linkage setups. In our shop, we typically go with the new service manual, and if working on an older 9.8A, refer to the earlier parts catalog.

Your terminology and description is a little confusing, and doesn't match up with the Tohatsu/Nissan names. I'm not sure about your "small" and "large" sleeves, nor the "small washer". There isn't supposed to be anything sleeving the driveshaft inside the LU. The driveshaft just seats into the pinion gear (bevel gear B), and is supported by the needle bearing. The gap liner is a shim (only a few thousandths thick), used to get the correct gear backlash, and fits in the machined seat just below the pump case lower. The oil seal is located just above the ball bearing. That extra stuff in the LU may have been put there by a previous mechanic, for some unknown reason.

I need to ask why you changed that gasket? They seldom fail. If you discovered water in the LU lube, a much more common problem is worn out oil seals for the driveshaft and prop shaft, and/or the o-rings for the shifter.

 

[Rick Russell]

Re: Nissan 4 stroke 9.8A drive shaft assembly

Thank you Paul.

I will go out and get myself these manuals before I tackle any other projects with the outboard and send the aftermarket manual to my mother in law!

I installed everything as you mentioned above, with the exception of the "small sleeve spacer", "Large sleeve spacer" and "small washer", which apparently shouldn't exist.

This is strange as this is the first time the engine has been taken apart, so it may have come from the factory this way? Or maybe the online shop that I purchased it from in 2002, sent me a rebuild with some nice little extra treats in there to help with proper spacing?

I'm afraid to admit that I only changed the gasket because the gasket came with my water pump kit and I said to myself," well, I'm already here. I might as well change this as well." Which, went against my father in law's advice of, ? This doesn't look like it affects your water flow problem at all. I would just leave it alone if I were you."

Notice how I was going to send the after market manual to my mother in law and not my father in law!

Thanks again Paul!

 

[britten]

Re: Nissan 4 stroke 9.8A drive shaft assembly

Thank you Paul.

I will go out and get myself these manuals before I tackle any other projects with the outboard and send the aftermarket manual to my mother in law!

I installed everything as you mentioned above, with the exception of the "small sleeve spacer", "Large sleeve spacer" and "small washer", which apparently shouldn't exist.

This is strange as this is the first time the engine has been taken apart, so it may have come from the factory this way? Or maybe the online shop that I purchased it from in 2002, sent me a rebuild with some nice little extra treats in there to help with proper spacing?

I have a 5 hp Nissan NS5B. I rebuilt the lower unit and after I got it all back together I see that I have 2 parts left over. can you get what it is? yes these 2 sleeves that shouldn't exist. now when I look at the schematics at Iboats. specifically http://www.**********/parts/search/...lier/NS5B/TRANSMISSION, WATER PUMP/parts.html this schematic if you look at the drive shaft marked 1 right below the bearing you can kind of make out these 2 sleeves, but they're not listed as a part you can purchase. so did this help space things correctly during assembly.... these must have a purpose. I have my engine back together and running everything feels and sounds fine. but what will happen after hours and hours of use.... have you figured out what 2 parts are for...?


anyone

Ben

 

[britten]

Re: Nissan 4 stroke 9.8A drive shaft assembly

I have a 5 hp Nissan NS5B. I rebuilt the lower unit and after I got it all back together I see that I have 2 parts left over. can you get what it is? yes these 2 sleeves that shouldn't exist. now when I look at the schematics at Iboats. specifically http://www.**********/parts/search/...lier/NS5B/TRANSMISSION, WATER PUMP/parts.html this schematic if you look at the drive shaft marked 1 right below the bearing you can kind of make out these 2 sleeves, but they're not listed as a part you can purchase. so did this help space things correctly during assembly.... these must have a purpose. I have my engine back together and running everything feels and sounds fine. but what will happen after hours and hours of use.... have you figured out what 2 parts are for...?


anyone

Ben

replace the stars in the link with **********

 

[britten]

Re: Nissan 4 stroke 9.8A drive shaft assembly

okay that link
http://www.**********/parts/search/...lier/NS5B/TRANSMISSION, WATER PUMP/parts.html

replace the stars with

boats dot net

this site blocks that domain

 

[TOHATSU GURU]

Re: Nissan 4 stroke 9.8A drive shaft assembly

Download the correct parts book here:
http://internetoutboards.com/PartsCatalogMenu.htm

 

[britten]

Re: Nissan 4 stroke 9.8A drive shaft assembly

Download the correct parts book here:
http://internetoutboards.com/PartsCatalogMenu.htm

well you see these parts we speak of in the diagrams, but there is not a specific part number unless they just come with the entire drive shaft assembly. I'm looking at the 5 hp nissan 1992 ns5b parts catalog. if you look at page 34 titled fig 8 transmission, water pump. Looking specifically at the drive shaft segmented box 1. looking below the drive shaft bearing you can see a visibility wider piece. this is the sleeve (mine is 3-1/8") we speak of. Then below that is the small sleeve(1/2"). you can really see the smaller sleeve in the diagram, its inside diameter is .005 of an inch smaller then the larger sleeve and keeps the bigger sleeve in place. so any idea how important these are. I had my lower unit put all back together then realized I left these parts out... doh... I rebuilt the lower unit (bearings, water pump, oil seals etc..)the transmission shifts smooth and everything is running like new. but what will happen after many hours of use can someone shed any light on the purpose of these parts

Ben

 

[pvanv]

Re: Nissan 4 stroke 9.8A drive shaft assembly

They are part of the driveshaft. Probably OK without, but I have never tried it. They will act as a spacer between the driveshaft bearing and the B (pinion) gear, amongst other things.