Shim for water pump

BOWTECH.JUSTICE

Petty Officer 2nd Class
Joined
Aug 26, 2012
Messages
170
2002 Nissan 50hp. NSD50A
I'm rebuilding the lower unit and to the point of assembling the water pump. Per the manual and parts diagram, it calls for a shim to be put on first before the pump housing. Somewhere along the line the previous shim has disappeared and when I was going to order a new one, there were 4 different thicknesses of shims offered. How do I decide which shim it is that I need? Or do I even need one? And before the haters respond about all the bad things of not doing it exactly how it says, I understand all of that, but it almost seems to fit together nicely without the shim. Thanks
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
That shim is for setting the lash in the LU. If it never had one, it is likely OK without one. If on the other hand, it did have one and you lost it, you may want to review your Factory service manual and get some dial indicators out to set the lash.
 

BOWTECH.JUSTICE

Petty Officer 2nd Class
Joined
Aug 26, 2012
Messages
170
The manual does show one which looks like it's for the pump housing to sit on the rim of the bearing for clearance of the pump seals and the bearings. Rough measurements with a tape measure tells me I should have clearance between the seal and bearing without the shim.
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
The issue is you may have too much clearance. You need the Factory service manual to check the LU backlash.
 

BOWTECH.JUSTICE

Petty Officer 2nd Class
Joined
Aug 26, 2012
Messages
170
Ok. So now, with me being a diy'er I don't have the proper tools and the gauge to measure pinion height is expensive. Are there options to measure that height? This outboard is on a rental pontoon and at this time I'm just trying to prolong its life as long as possible for the least amount of money.
 

BOWTECH.JUSTICE

Petty Officer 2nd Class
Joined
Aug 26, 2012
Messages
170
This is why I love this site. I'm no expert on anything but I'm willing to try anything, so it's nice to be able to get good info from the experienced ones
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
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36,043
Mechanics blue / AKA Prussian blue-----Is a product that old timers used.----This can be used to observe proper tooth contact.-------Must pull up on the driveshaft when testing.-----Look into using that stuff.
 
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