Do you have to replace bearings? If so, how often?

[Draven]

I have a Kraton 4s.

6 full battery runs total.
5 of them have been on concrete/street only
1 was in dirt/wet grass and was hosed down and cleaned immediately after.

I have a new kit of sealed bearings and was wondering, do I replace now? or wait until they go bad?
They don't show any signs of wearing out yet...
How often do you recommend replacing bearings for someone like me who drives 80-90% on street?

 

[Notorious J]

That's a hard question to answer @Draven. The issue is what might happen if a bearing seizes. In a dif or inside the motor module, the results would have a domino affect and likely destroy other parts. Bearings can be cleaned and maintained and since you run mostly "clean", you might be able to keep the stocks longer than normal. Once dirt gets in and starts to wear down the balls, it's a matter of time before they go. Even sealed bearings don't last forever. Take out the ones that are easiest to get to (hubs) and give them a whirl. If they feel gritty, chances are that the internal ones aren't far behind. You can clean and relube them with brake cleaner spray and some thin oil. 3 N 1 has always worked for me.

 

[jkflow]

Stock bearings, I'd throw them out now. Water penetrates the seals and they are already damaged because you didn't immediately tear them apart and oiled them. My guess they will start binding in 1-2 sessions. Keep water away or you need to break it down all the time or hope that it is all watertight (stock bearings are NOT!).
On the sealed, really depends on your driving conditions. I oil mine once a season (or now because I'm bored) and I'm on grass and dirt all the time.

The critical ones: - all the wheels, I'd do them now
what can wait - bearings on the diffs unless you blasted water into them

FYI, driving on bad bearings will lead to higher motor temps and it will ultimately die because of it.

 

[Draven]

Thanks guys. Good points.

I was thinking more about performance, but if there's a chance stock bearings can melt/damage other components then I might as well change them all out now.

 

[jondilly1974]

I would swap them before you need to. Meaning, I would do it now because you never know when that stock bearing is going to seize. You won’t know until after and that’s too late. You’ll likely melt plastic, usually the yokes, which means stripped diff gears.

 

[Draven]

Replaced all the bearings (except motor). Differential bearings looked OK, but the wheel bearings looked bad. Gritty with dirt and orange from rust. It took about 4-5 hours total with hand tools this first time around, but overall wasn't too difficult. Highly recommended to anyone with the Kraton.