Autopsy of a "good" IMS bearing

[Steve Tinker]

James....
As per BYprodriver said.

But without knowing the history, the results are too simplistic to draw any meaninfull conclusions, as the pictures only show a slightly worn bearing that could have been in operation for 10,000 miles or 110,000 miles.
If the mileage & service history was available, the resulting wear would be more meaningfull. And as you know, some high mileage engines won't have as much bearing wear as others even though they have had a similar maintenance regime.

[Jamesp]

Originally Posted by Steve Tinker

James....
As per BYprodriver said.

But without knowing the history, the results are too simplistic to draw any meaningful conclusions, as the pictures only show a slightly worn bearing that could have been in operation for 10,000 miles or 110,000 miles.
If the mileage & service history was available, the resulting wear would be more meaningfull. And as you know, some high mileage engines won't have as much bearing wear as others even though they have had a similar maintenance regime.

I found it interesting that there are 8 balls in the bearing, and 8 equally spaced wear patches on the inner ring with 7 on the outer. I don't know what that means, if anything. I was hoping someone else might chime in.

[Walter White]

Hi,
I have been playing with ball bearings, running them at high speed until they fail to see how and why. What I have observed is that as they wear, they produce a metallic dust that is incredibly fine. I think that the oily "goo" that so many people have mentioned is a mixture of oil and this metallic dust.

[thstone]

Originally Posted by Steve Tinker

But without knowing the history, the results are too simplistic to draw any meaninfull conclusions, as the pictures only show a slightly worn bearing that could have been in operation for 10,000 miles or 110,000 miles.

^ What Steve said. That's why I was wondering about the mileage.

[Jake Raby]

Glad to see this autopsy done. This is what we do with the bearings that are extracted, and its how we have gathered so much trend data.

When people have an IMSR carried out and they say "I felt the bearing and it was fine, I changed it for no reason", I just shake my head and ask them if they cut the bearing apart. The answer is always no.

If they did, they'd find something resembling what is detailed in this post. Judging a book by its cover has never been a good idea.

[WhipE350]

Originally Posted by Jake Raby

Glad to see this autopsy done. This is what we do with the bearings that are extracted, and its how we have gathered so much trend data.

When people have an IMSR carried out and they say "I felt the bearing and it was fine, I changed it for no reason", I just shake my head and ask them if they cut the bearing apart. The answer is always no.

If they did, they'd find something resembling what is detailed in this post. Judging a book by its cover has never been a good idea.

Well not everyone says "no" . However I will go back over it and look again with stronger magnification. Mine though was double row, very low failure rate.

[Jake Raby]

That bearing was at a stage 3 failure point. I have caught a few of them like this, the single row IMSB is at stage 3 for a very short period of time compared to the dual row which will run this way for much, much longer.