Watch your thrust bearing!

[duanehydro]

If anyone is interested, this is what will happen if your thrust goes away....wasted the shaft, imp, bushings, everything....then proceded to take the motor with it...starting with it's thrust, and wiped everything out. :smile20: :smile13: VERY expensive...And it still ran fine, and he never heard a thing!! Until the motor gave. :smile26:

 

[Devilman]

So, is there a way for the average Joe to check the thrust bearing to make sure everything is kosher before it craps out?

Or do you just gotta wait tillthe bearing pukes & destroys everything to suddenly realize, "Hey, my thrust bearing is bad...."  :grin:

 

[duanehydro]

Man, I just don't know. the pump in this boat is buried.....can't say what killed it, but I assume lubrication. Don't know. maybe alan will chime in soon.

 

[KONA77]

lost in rpms,  from what i understand is almost to late,  noisy bearing should be the first sign.

Rebel son,  learned this lesson the hard way.

 

[Devilman]

Man, I just don't know. the pump in this boat is buried.....can't say what killed it, but I assume lubrication. Don't know. maybe alan will chime in soon.

Or lack thereof? :undecided: Mine is easy to get to, so I give it a few shots of grease every time I take it out. Surely I'm not over-greasing it... :huh:

 

[KONA77]

Man, I just don't know. the pump in this boat is buried.....can't say what killed it, but I assume lubrication. Don't know. maybe alan will chime in soon.

Or lack thereof? :undecided: Mine is easy to get to, so I give it a few shots of grease every time I take it out. Surely I'm not over-greasing it... :huh:

never to much grease.....

 

[Devilman]

never to much grease.....

Regardless, I gotta pull mine this fall....  :tongue:

 

[TintMan]

Drive shaft running to deep will kill it too... :smile20:

 

[wildbunch]

Man, I just don't know. the pump in this boat is buried.....can't say what killed it, but I assume lubrication. Don't know. maybe alan will chime in soon.

I shot a little grease to it every other time I took it out. As a matter of fact it crapped out at Hydrofest & i greased it up that day before. It never vibrated made any noise, still ran ok I guess just wouldn't turn but 5200 rpm's at first then went to 4700 that's when I figured out there was something going wrong. By the time I got back to boat ramp oil pressure at idle was "0" temp was 200 never runs over 180 even in that hot ass lake. and the rest is history. New motor coming, complete pump rebuild.  :smile13: :smile13: :smile18:

I knew I should of stayed under that awning drinking more cold beer.......... :smile30:

 

[J C Gordon]

Man that sucks!! And yep beer is usually cheaper than a new motor and pump.. :smile13: But its hard to correct something ya caint see or hear...

 

[Patchman]

I never thought about how a pump loads a crankshaft differently than a transmission. If that front pump bearing starts to go, the only thing I see that would keep the pump shaft from moving forward is the impeller and wear ring. At that point I guess the only other factor would be engine to pump placement. The closer the motor, the more chance the thrust bearing in the motor can recieve pump load. That sucks, never really thought about that before. Good to keep in mind when starting on new project!

 

[janjon]

Yep, I have killed two motors in two years due to thrust bearing issues. The first was due to the thrust bearing in the pump itself going bad due to the grease monkey not doing his job. The second, I think, following a pump rebuild, was due to soft stringers and resultant flexy motor mounts letting the motor move back under acceleration, at least, and maybe also while turning, putting forward load on the thrust bearing of the engine. And there 'ya go, another one bites the dust. Thrust bearing debris kills cam lobe, and there's 1/16'' end play on the crank. Structural work on the boat underway. To maybe answer the question of how you can check thrust bearing condition, open handhole cover, insert hand, grab shaft and try to move the shaft front and back. All males should have a good grip on this technique. All gals should too. Any end play would not be good. in the pump, that is.

 

[J C Gordon]

Just another tip, I have an autogreaser on mine. Fill it up with grease and let it take it as it needs it..

 

[3boatpaul]

i know you jet guy's use one peice shaft's from coupler to coupler,  think.gif  and it is me just thinking ,
in my v-drive set up i run a slider on my drive shaft between the tube and the flange as do most v-drive's.
would that set up work in a jet. ?????    a slider on a v-drive allowe's us to slide the motor assy forward or
or backward's to the gear box. i think you should be able to use that system to give you some wiggle room
to be able to save your motor a lot of grief. JUST THINKIN  think.gif

 

[HellinnFrnt]

it would work on some of them ... mine I don't think it would shaft is only 7" long

 

[jdeaton]

We really have a slider in place, or so to speak,  to properly install the motor in a jet, let the motor resting on the mounts, slide all the way to the rear, then move it forward at least 3/8 on an inch, some people go farther, but ARS recommends 3/8.  That's allows the rotating system to float.  Also 3 degrees is max on drive shaft alignment.

 

[WAFOBABY]

very good info to keep stored