Replacing Single Crank Bearing- Good or Bad Idea?

[YouCanDooIt]

Hey guys,

I just picked up a 97 spx project ski. The PO took the engine out to diagnose a problem and the stator was damaged pretty bad from the mag cup rubbing against it. He took it to a shop and they told him the front crank bearing was bad.

When I got home I used a pry bar and could lift the flywheel/crank and could see it moving. The engine turns over very smooth still, and due to the condition, doesn't appear to have very many hours on the motor or ski.

Soo my question is... Can I just replace the two front bearings and throw it back together? is this a good or bad idea and why?

My concern is that it may have damaged the other bearings, but as I said it turns over very nice and there is no noise from any of the bearings. I am not against buying a refurbished crank, but I have a press and know I could replace them pretty easy and use OEM bearings for about $60.

 

[ski-d00]

bad idea, there's a reason the front bearings failed and the rest of them will be next in line to fail. unless you're a metallurgist and can examine the bearing microscopically as well as measure .0003" tolerance, just the feel of a bearing can be misleading. do it right, do it once. it will cost more but the peace of mind will be worth it.

 

[Minnetonka4me]

In general I agree with the above statement. But...in a recreational application knowing that I might have to pull it apart again...I would.

 

[YouCanDooIt]

unless you're a metallurgist

Well unfortunately..no I'm not lol. Your right, and I am not opposed to spending the money to do it right. I'm kinda in the same boat as minne though. If the SHTF after a season or so I don't really mind pulling the motor out and rebuilding, and I wouldn't really be out much just the two bearings and a gasket kit. I am throwing another used bottom end into the SPX to get it ready to ride until I finish restoring my XP and selling it when the time comes. If I replace these bearings and use it, it will probably be going into my GTX which I believe the current engine is on it's last leg anyways.

 

[Robj]

Bad idea, because if some bearings already failed, chances are that the others are not far behind. The failed bearing caused the others to wear at an increased rate and I am sure they are close to failure as well. Fix it right the first time, or fix it right the second time, your choice. Also if the crank fails, it can do case damage as well which would be even more expensive to fix.

 

[donkey]

i would think if u can move the end of the crank due to bad brgs on the end,the others are loose as well,otherwise,if the "middle" set of brgs are good,then u r just bending the crank to see the movement at the end.ive had a crank out,not really a "bendy" part.
just my .02cents

 

[YouCanDooIt]

That's true, a crank is definitely not "bendy", at least I hope that is not the case with this one LOL. Its very slight movement and you have to use a pry bar to see it so I don't know. I had planned to take the crank out today and look it over but never got to it. I'm guessing the other bearings at the least have slight damage, I mean even at idle the vibration and weight of the crank wobbling would have to be hell on the other bearings. I just don't know how long it was ran like that. I believe I could replace all the bearings my self if I really wanted to, but the cost of OEM bearings and seals are just as much or more than a reman.

Can someone explain what would cause a outer bearing to fail like this? I have never really seen or heard of it happening before, but is it common?

 

[Jetskigoodies]

The front seal probably just needs to be replaced as well. I would have a new bearing pressed on. If you can get another season or 2 why not. As long as the rods have no up and down play and the rest of the bearings have no chatter and spin smoothly then give it a shot, I know a few of the senior members do it, at least to the outer bearings.

 

[68ragtop]

It sounds like it has to be torn down regardless, so I would rip it open & measure things up on the crank & see what you have.