Carbon ring and floating ring are not even close to touching

[Cbord]

New to the forum so hey everyone. What went wrong for this to happen? I have had the ski about 2 years and have put about 20 plus hours on it in the current configuration so how is this possible. Motor hasn’t moved. Circlip is in place so the floating ring hasn’t moved forward. The only thing that has happened was a coolant hose clamp failed and lost all of the coolant. This was the first run since then. Could the coolant shrink the boot? Can the drive shaft shift forward somehow? It looks like I need to tear it down but a logical explanation would make me feel better. Thanks

 

[mkov608]

Is there any axial play in the driveshaft? From your picture, it looks like the c-clip isn't in the groove. Push the floating ring forward and see if it's covering the groove.

 

[mkov608]

On the end of the driveshaft (PTO end) there is a rubber bushing. If that bushing has disintegrated, it's possible you could develop too much axial play that would allow this to happen ... just a theory anyway.

 

[Cbord]

I can’t really move the drive shaft either way. In that picture the floating ring is all the way forward and over the c clip. When I pushed the ring back I could see the c clip in place. Is that what you mean? The bushing could be it. Is there anything attached to the driveshaft at the rear stopping it from moving? I’ve never had one apart but I guess that is gonna change[emoji21]

 

[mkov608]

Ok. Download your shop manual from seadoomanuals.net and flip open to page 12-03-4; you can find the tools you need on Ebay. Required tools are listed in the driveshaft instructions.

First things first, never touch the face of the carbon seal or the face of the floating ring. The two surfaces form a mechanical seal. During operation, a thin film of water cools and lubricates this seal; this is why the manual says not to run the ski out of the water for more than 5 min ... you burn things up. Damage or contamination of these surfaces will result in leakage and rapid wear.

Next, here's a picture of the c-clip in the groove. It looks like your c-clip has come out of the groove and moved forward on the shaft; this allowed the floating ring to move forward on the shaft. (Based on what I can see in the picture you posted)






Here's a picture of the c-clip groove's position on the shaft. When properly assembled, the bellows applies pressure on the carbon seal, and the carbon seal applies pressure to the floating ring; the floating ring is forced against the c-clip. The c-clip keep the mechanical seal joint (carbon seal and floating ring) together, and it keeps the drive shaft from falling out too when you remove the jet pump. ;-)



There are two o-rings (16) go inside the PTO and seal the oil cavity. You'll need new o-rings when you reassemble.

There are also two o-rings inside the floating ring; these o-rings keep lake/sea water from bypassing the mechanical seal and flowing up the driveshaft. Water will take the path of least resistance and flow along the driveshaft, and we don't want that; we want the water to force its way between the floating ring and the carbon seal. Sometimes the floating ring will stick to the driveshaft; spray some XPS lube between the floating ring and the driveshaft.


If I were in your situation, I'd replace the four o-rings, carbon seal, floating ring, and bellows.

 

[mkov608]

I just down loaded your original picture; the c-clip is all the way up against the PTO housing, so there is no way it's even close to the groove it's supposed to rest in.

What made it pop out of the groove ... now that's the mystery, but based on the age of your ski, I would suspect a weak bellows (insufficient tension) allowed the floating ring to float to the rear to the point where the c-clip was exposed, then if came out of the groove.

 

[Cbord]

Thank you for the reply. I took another pic with the floating ring pressed back to expose the c clip. Unless I’m missing something it is in place right? Even with the floating ring back it still doesn’t touch the billow. I will start breaking it down next week so hopefully will figure it out. Having an explanation would give me a little more confidence in the repair.

 

[Cbord]

 

[Cbord]

From what I’ve researched that is what it’s supposed to look like. Looks good to me

 

[mikidymac]

On the diagram above #12 the driveshaft actually shows 2 grooves just in it. Are you sure there isn't a second groove further to the rear for the "C" clip that is hidden by the stainless hat?

 

[mkov608]

See previous explanation.

 

[ski-d00]

From what I’ve researched that is what it’s supposed to look like. Looks good to me

Definitely not what it is supposed to look like. First, check your motor mounts by trying to rock the engine, you'll have to push hard.

 

[mkov608]

I think his comment about looking right was limited to the position of the c-clip in the groove on the driveshaft. I don't think he'll find the problem until he pulls it apart.

 

[ski-d00]

I've seen a gap that big a couple times. Both times all 3 motor mounts were broke/missing/sheared bolts. The motor will move forward until it hits the front motor mount or hull support for front motor mount and stops. Will run and drive in that position but will move around under load.

There's only 1 groove in the driveshaft big enough for the c-clip so that part is correct. I misunderstood what he said he looks good.

If you look closely at his pic, you can see the carbon dust on the bottom of the hull right at the carbon seal where it should be. It really looks like the motor has moved forward since that flap on the rear oil seal boot normally touches the carbon seal.

The reason a coolant hose clamp failed might be because the motor was moving around and pulling on it. They don't normally just fail. Which coolant clamp failed? I'm going to guess it was one of the ride plate heat exchanger hoses.

 

[Cbord]

Yes I think the c clip is in the right position but will check better today. I thought there was only one channel as well. That would def make the most sense ski-doo I just thought I would have been able to tell by looking. I will check the motor mounts better today. And it was the ride plate clamp but it was nearly rusted through so didn’t think anything of it. Thank you for the replies and will report back later[emoji1360]

 

[mkov608]

I've seen a gap that big a couple times. Both times all 3 motor mounts were broke/missing/sheared bolts. The motor will move forward until it hits the front motor mount or hull support for front motor mount and stops. Will run and drive in that position but will move around under load.

There's only 1 groove in the driveshaft big enough for the c-clip so that part is correct. I misunderstood what he said he looks good.

If you look closely at his pic, you can see the carbon dust on the bottom of the hull right at the carbon seal where it should be. It really looks like the motor has moved forward since that flap on the rear oil seal boot normally touches the carbon seal.

The reason a coolant hose clamp failed might be because the motor was moving around and pulling on it. They don't normally just fail. Which coolant clamp failed? I'm going to guess it was one of the ride plate heat exchanger hoses.

Excellent Observation .... carbon seal dust! Engine mounts are supposed to be inspected every 100 hours; I wonder how many hours are this ski. My skis are right around 135 hrs, and I haven't had any problems with the mounts like I did with my old XP.

Cbord, if your engine did move, you'll need all new components (mounts, carbon seal, floating ring, o-rings etc) and OBTW, there is a revised driveshaft for our skis. You may want to look into that.

 

[Cbord]

I have figured it out. Definitely the engine mount. Looks like it damaged the impeller bearings and all. How big of a job are the mounts? Back two looks easy enough but do I need a hoist or can it be done without it? I haven’t really researched it or looked in manual

 

[Cbord]

Does the pump housing look ok? The bearing are laying in the come and it damaged the edge of the where the bearings press against. I think anyhow

 

[Cbord]

And last what else should I be replacing while I have it apart? I am replacing the impeller and wear ring and of course the bearings, boots, rings and seals. Ski has 205 hours on it

 

[noviceskier]

needs some grease

 

[mkov608]

Does the pump housing look ok? The bearing are laying in the come and it damaged the edge of the where the bearings press against. I think anyhowView attachment 39674

You'll need to disassemble and clean out all the old grease. The post pictures of the pump.

 

[mkov608]

And last what else should I be replacing while I have it apart? I am replacing the impeller and wear ring and of course the bearings, boots, rings and seals. Ski has 205 hours on it

There is only one bearing assembly for the jet pump; it's a hub unit. SKF makes the OEM bearing, but I have had good luck with WSM bearings. You can use the XPS grease or ExxonMobil SHC 100; the two are compatible with the factory fill the bearing comes with.

Most of your questions will be answered by the shop manual.