Do I need rod bearings? What explains this?

[pissedoffpatriot]

My B20 d-950 Kubota has run strong for 20 years. Lost compression so I'm doing a ring job. Then I noticed these bearings. See attached picture. What could cause this? What should I do? Thanks.

 

[Nicksacco]

What do the journals and other side of the bearings look like?

 

[TheOldHokie]

My B20 d-950 Kubota has run strong for 20 years. Lost compression so I'm doing a ring job. Then I noticed these bearings. See attached picture. What could cause this? What should I do? Thanks. View attachment 138286 View attachment 138287 View attachment 138288

I dont know exactly what caused the erosion but you definitly need bearings and probably more given the looks of the sludge on the pistons.

Dan

 

[hagrid]

Wow. I've never seen that type of localized erosion except for chem/galvanic or cavitation.

 

[lynnmor]

How often is the oil changed? Do you use additives (snake oil)?

 

[Russell King]

I have seen that on some bearings with high load (specific pressure). The Babbitt material may not have been bonded to the steel backing and fatigue set in and cracks out a portion of the Babbitt.

 

[whitetiger]

It is typically caused by water vapor, along with not changing the engine oil or using a subpar engine oil.

 

[jaxs]

If you expect any degree of longevity and reliability I don't see any way around removing crank shaft for at minimum polishing and most likely turning. Considering amount of sludge and low compression along with lower end damage I expect you are looking at total rebuild or finding a used engine.

 

[Nicksacco]

Here's a video I thought y'all might like.
The guy on the left is "The Motor Oil Geek" (another youtube channel).
His stuff is great but I confess, I don't pretend to understand everything.

This video however talks about journal bearings and provides some good knowledge.
I wanted to run out and change oil in everything I owned!