Tip/trick for reassembling Water PumpJ10RCDB 1986 9.9hp.

cprodave

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Installing a new Water Pump and am having trouble inserting Impeller Housing to Driveshaft Seal 318972 into the Impeller Housing and Seal Assembly 388289. This seems to be a REALLY tight fit. The Seal 318972 has a nice chamber on the topside outside diameter but unfortunately the underside has no such chamfer. As I try to press this into place the Seal will not stay level going into the Housing. The Seal keeps going canted/crooked.


So what is the best way to get this Seal into the Housing? Can I "cheat" by filing a very small chamfer on the underside of the Seal? Or just use a large C-Clamp with 2 rigid metal plates to press the Seal into the Housing?
 

racerone

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Just use a vice or C-clamp and push it in square.----Everyday easy.
 

cprodave

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Thanks for the tips--I used dish soap and vise--this worked great. Sorry if I was paranoid about breaking the Housing--I was unsure how strong that composite/plastic Housing material is.

I noticed a small (approx. 1/2 inch diameter) O-ring had fallen onto the floor when I removed the Lower Unit a couple weeks ago.. And there is a similar but slightly smaller O-Ring in the Water Pump Repair kit 394711 (or it may have been Sierra 18-3327). But I don't see on any diagram where this O-ring goes. Does this O-ring go on the Drive Shaft just below the splines? Or elsewhere?

Also 3 Grommets are included in the Water Pump Kit. Let's call them Short, Long and Funnel-shaped (sorry no pix). The Short Grommet was on the old Housing, but the Long Grommet seems to fit the Water Tube more positively. Which one do I use? And is the Funnel-shaped Grommet supposed to go at the top of the water tube? It seems like 2nd or 3rd Grommet would be a Midsection or Powerhead part, but I don't see Grommet that in those diagrams. I do know that on other outboards a Grommet at the top of the Water Tube is crucial And wouldn't I have to lift Powerhead to install a new Grommet at top of Water Tube? Or do I only need the Short Grommet for 9.9hp (toss the other 2)?

Reason I ask is water flow out the Pee hole was previously not very strong, therefore I suspected Impeller was bad. But the Impeller looks quite good/useable...so I am thinking Grommet is leaking...or bad thermostat.

Thanks for ongoing advice.
 

tomhath

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There should be an o-ring in the grove at the top of the drive shaft. A tiny bit of grease on it helps when you re-assemble.
 

racerone

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The parts book shows the 86 models to have the second seal on the seal housing below the crankshaft.-----This did away with the need for the o-ring in the groove below the spline.----But it is an 86 model and the 1974 lower unit will fit on it.-----Also a 2007 lower unit will fit on it.----No telling from here if you need the o-ring on the shaft.
 

cprodave

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As Tomhath mentions there does seem to be a "grooved chamfer" (I would call it) at the very top of the Drive Shaft. The way this O-ring simply fell out while removing the Lower Unit leads me to conclude this O-Ring was sitting on top of the Drive Shaft in this "grooved chamfer". The old O-ring will sit/stay (with a bit of grease) whereas the new O-ring (which is smaller in both O.D. and I.D.) will not sit/stay in this groove/chamfer.

On the other hand, there is evidence on the Drive Shaft of something being around the Drive Shaft just below the splines in this very shallow groove. The new O-Ring fits OK in this position below the splines.

So I will put the old O-Ring on top of the Drive Shaft and the new O-ring below the Splines--can't see any harm in using the new O-ring as sort of an extra seal to guard against any water getting up into the DriveShaft/Crankshaft joint. Of course a liberal coat of grease goes there too.


Thanks for the inputs.

BTW any ideas/input on the choice of 3 water tube Grommets?
 

racerone

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????------They never ever had an 0-ring that sat loose on the very top of the driveshaft.----Only an o-ring in the groove below the spline.----Then they did away with the o-ring in the groove by adding a second seal on that housing below the crankshaft.----But it is your motor so do as you like.
 

tomhath

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Dec 5, 2007
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Racerone knows far more about these motors than I ever will, so you would do well to take his advice.
 

cprodave

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Sorry--I misunderstood Tomhath's input. I was thinking he meant at the very top of the DriveShaft (vs. below the Splines).

I never intend to to ignore the input of those who have vastly more experience than me. I am only trying to reassemble this puzzle (of unknown Lower Unit vintage) including this O-ring that mysteriously appeared during disassembly.

Thanks all.
 
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