MSX Pump Assembly

[ph2ocraft]

I was taking apart an MSX pump assembly with driveshaft, thru-hull fitting (now called a bearing support) etc.
While servicing the carrier bearing assembly I could of sworn the seals were in backward but I'm not 100% sure as I popped the seals out to freshen them up.

I have a new carrier assembly in the garage so I'll check it in the afternoon.

If I'm not mistaken the seal spring will be exposed to the elements (especially salt water). The spring will of course fail and no longer allow the rubber portion of the seal to keep pressure around the driveshaft.
This will allow water to push past the driveshaft and into the hull.

[K447]

I was taking apart an MSX pump assembly with driveshaft, thru-hull fitting (now called a bearing support) etc.
While servicing the carrier bearing assembly I could of sworn the seals were in backward but I'm not 100% sure as I popped the seals out to freshen them up.

If I'm not mistaken the seal spring will be exposed to the elements (especially salt water). The spring will of course fail and no longer allow the rubber portion of the seal to keep pressure around the driveshaft.
This of course will allow water to leak into the hull.

Here is the inside face of my 2004 MSX 140 bearing carrier. I have not looked at the water side of the bearing carrier.

I was not aware of any regular service schedule for this assembly, other than 'Inspect at preseason, and at year end' (2003 MSX Service Manual page 5.1)
Does 'inspect' mean actually take it out of the hull, or just eyeball it after removing that annoying-to-undo-the-bolts metal tunnel cover?

Page 5.8; The bearing carrier on the MSX 140 uses sealed bearings.
Bearing maintenance or lubrication is not required.

Why did you need to service yours?

Is the seal spring coated or made of a material that will not corrode easily?

[ph2ocraft]

Water side would be the larger issue as the interior should be dry and the spring not subject to as much corrosion.
The spring exposed to the water will only last so long, if the seal were reversed my guess is water intrusion will be delayed for quite some time.

[ph2ocraft]

Here's a picture of a brand new unit, I don't think the springs should face or be subject to the elements.
I wonder if Polaris will send me a corrected unit?

[K447]

Water side would be the issue as the interior should be dry and the spring not subject to corrosion.
The spring exposed to the water will only last so long, if the seal were reversed my guess is water intrusion will be delayed for quite some time.

Hmmm. Jay's post implies that the factory assembled units may, or may not, have the seals installed wrong way around.

Was he talking about the water side, or both sides?

All 2003 and 2004 MSX, or just part of the production run?

My understanding of what the seals do is that the seal on the water side needs to protect against water intrusion along the shaft, while the seal on the motor side needs to protect against water (if any is inside the hull) AND air from getting drawn into the pump when under power, when there is suction in the pump intake area, where the drive shaft goes.

So the correct side for the spring may be different for the hull and water sides of the bearing carrier.

It would be good to know what a correctly assembled carrier looks like, on each side.

[K447]

Water side would be the larger issue as the interior should be dry and the spring not subject to as much corrosion...

Perhaps it would be an idea to smear some waterproof grease around the spring, on the inside seal?

[785 lugs]

it should use a stainlees spring anyway i don't see how it would affect it ,has anyone had a rusted out spring yet ???

[ph2ocraft]

Perhaps it would be an idea to smear some waterproof grease around the spring, on the inside seal?

Good idea, anything to help preserve the life of it.

[ph2ocraft]

it should use a stainlees spring anyway i don't see how it would affect it ,has anyone had a rusted out spring yet ???

You sure it's stainless? Mine looked like crap, corroded like crazy but not severed...yet. The inner seal/spring still looked pretty good but I'm reversing mine for some peace of mind.
Mine has never been in the ocean but has been in some brackish stuff...and let's face it, who's cleaning or flushing that area out?
I also wonder if it's possible to get a twig or other "stuff" up there that may dislodge the spring, not worth the risk to me.

[2&4strokepolaristech]

yes i have seen some of the seals on the water side with the springs facing outward. they should be facing inward. if you should happen to find that the seals are incoreect when serviceing you bearing housing I would replace them and inspect the bearing. when the are reassembled make sure that on the water side the springs face inward. As mentioned by Al the coupler side one does not make that much diffrence.

I would also like to mention that everyone that flushes their unit on a ose should not run it for more than 2 minutes at a time. the reason being that the seals the face the water side are cooled by the machine being in te water. If the unit is not in the water you will start to melt the seals and eventually damage you seals and cause premature failure. THIS APPLYS TO ALL PWC'S!!!!!

yes it is a stainless spring but the spring wire diameter is small and will still shorten its like. If you ride in salt water I would service the bearing housing every 75-100 hrs or 3 years. THAT IS JUST MY SUGGESTION!


AL WAY TO PAY ATTENTION TO DETAIL BUDDY!!!!!!! GOOD EYES!!!!!