Tore down a 01 ETH today because of engine knock coming from #5 cyl. The lower half of the #6 main bearing had flaked off in multiple places causing the pin oiler to clog with the bearing flakes. This in turn gaulded the #5 piston and severely scared the clylinder wall. All of the other bearing/cylinders/pistons etc... were o. k. The motor had 179,xxx miles on it. Have any of you encountered this problem before? Any feedback would be appreciated.
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# 6 lower main bearing failure
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Vaughn MacKenzie
TDR MEMBER
Did it have a Fram filter on it? 
Ton of miles? My neighbor delivers airconditnors for a local manufacturer from the plant to sites all over the US. He has a little over 150,000 miles on his 2001 auto equipted 3500.
That thing runs hard all the time, can you say 80 plus mph for hours at a time. It's stock, and the only real trouble he's got is the rear main has started leaking pretty bad.
Talked to him the other day and he's about to get a new truck.
That thing runs hard all the time, can you say 80 plus mph for hours at a time. It's stock, and the only real trouble he's got is the rear main has started leaking pretty bad.
Talked to him the other day and he's about to get a new truck.
Have anymore details?
Was this used for heavy towing?
Properly maintained? Upgraded?
In my opinion the #6 and #7 lower bearings would have more wear, from their position closest to the transmission.
But, it is not normal for these to fail.
Was this used for heavy towing?
Properly maintained? Upgraded?
In my opinion the #6 and #7 lower bearings would have more wear, from their position closest to the transmission.
But, it is not normal for these to fail.
Mr. Williams,
Given your location, I'm assuming you might be a Cummins employee. I certainly hope your question regarding heavy towing doesn't have the implications I fear it might. You see, I bought this truck on its towing reputation - see signature. If I didn't tow our 13,500 lb 5ver, it's quite likely that I would not own this truck and would not be a Cummins customer. Am I to expect 170,000 mile engine life from my ISB? If so, I'd better trade for a motor home with Cat power! Quickly!
Rusty
Flaked Mains
I don't know what your oil pressure was running, but on our large Waukesha gas engines when the main-bearings flake, it usually means that they were seeing excessive oil pressure (cavitation).
One of our engine vendors (I won't mention who) had a bad run of bearing shells that did not have good adhesion of the babbit to the base material. Those didn't show up until we pulled them at 25,000 hours for inspection. They were flaking also. This vendor is in the process of covering our failures with this run of bearings and the replacement of existing bearings of a given serial number series.
Just a couple of things to think about.
I don't know what your oil pressure was running, but on our large Waukesha gas engines when the main-bearings flake, it usually means that they were seeing excessive oil pressure (cavitation).
One of our engine vendors (I won't mention who) had a bad run of bearing shells that did not have good adhesion of the babbit to the base material. Those didn't show up until we pulled them at 25,000 hours for inspection. They were flaking also. This vendor is in the process of covering our failures with this run of bearings and the replacement of existing bearings of a given serial number series.
Just a couple of things to think about.
B.G. Smith
TDR MEMBER
Main bearing
Sounds like an isolated incident and probably with a sensible explanation. Having seen a few main bearing failures over the years (in gasoline engines ). Usually if only one main goes bad it will be the rear. If an engine runs very long with one of the center mains looser than the rest it will sometimes break the crankshaft due to flexing. I sure wouldn't worry about the crank shaft being a problem with the Cummins engine. bg
Sounds like an isolated incident and probably with a sensible explanation. Having seen a few main bearing failures over the years (in gasoline engines ). Usually if only one main goes bad it will be the rear. If an engine runs very long with one of the center mains looser than the rest it will sometimes break the crankshaft due to flexing. I sure wouldn't worry about the crank shaft being a problem with the Cummins engine. bg
Joseph Donnelly
TDR MEMBER
#6 is the thrust main, but only the block side of the main has a thrust bearing. What thrust clearance does the crank have? I also don't think it is a good idea to have the clutch switch that Dodge uses. You have to depress the pedal to start the truck. No oil pressure and the clamp load of the pressure plate is translated to the thrust surface.
RustyJC,
My questions regarding this Engine are to learn some sort of history behind this Engine.
I do not represent Cummins Engine Company, but I am an employee who takes great pride in manufacturing ISB's, and
everynight on 3rd shift, I install these same bearings.
My opinion is that this is a premature failure.
Sh-- does happen, Engines fail, but it is in no way typical.
The typical ISB lasts for a very long time, ask the members on this site with 500,000 miles or more.
Some of the engines I see sitting in the graveyard are either a part related failure, or an engine thats had one dogged out life
with very low maintenance or none for that matter (like sand in the engine, water in the engine, 2 quarts of oil in the engine, the list goes on).
My interest is of personal concern for a quality product.
So keep us posted!!
My questions regarding this Engine are to learn some sort of history behind this Engine.
I do not represent Cummins Engine Company, but I am an employee who takes great pride in manufacturing ISB's, and
everynight on 3rd shift, I install these same bearings.
My opinion is that this is a premature failure.
Sh-- does happen, Engines fail, but it is in no way typical.
The typical ISB lasts for a very long time, ask the members on this site with 500,000 miles or more.
Some of the engines I see sitting in the graveyard are either a part related failure, or an engine thats had one dogged out life
with very low maintenance or none for that matter (like sand in the engine, water in the engine, 2 quarts of oil in the engine, the list goes on).
My interest is of personal concern for a quality product.
So keep us posted!!
Out of curiosity......
... for anyone who can answer... ... . when a bearing like this flakes, is it because the heat (through friction?) made the bearing come apart---guessing there's a variety of circumstances that could lead to this happening... ... . could foreign matter do this? Sounds like when the bearing comes apart, the orifices the oil passes thru get plugged, and away we go..... but what would make the bearing do this in first place???
Despite the # of posts by my handle, been on this site since the CDW days (changed handle when site changed last time) ... ..... and, even though I haven't been prowling here much of late, I've only heard of 3 rigs EVER having problems on such a major scale--maybe Joe or someone can recall hearing of more. While I can p*** and moan all day over the lack of stock power (in my case), I think anyone is hard pressed to diss on the Cummins for its overall reliability (except for lift pump issues--).
Flu ridden Rogue
... for anyone who can answer... ... . when a bearing like this flakes, is it because the heat (through friction?) made the bearing come apart---guessing there's a variety of circumstances that could lead to this happening... ... . could foreign matter do this? Sounds like when the bearing comes apart, the orifices the oil passes thru get plugged, and away we go..... but what would make the bearing do this in first place???
Despite the # of posts by my handle, been on this site since the CDW days (changed handle when site changed last time) ... ..... and, even though I haven't been prowling here much of late, I've only heard of 3 rigs EVER having problems on such a major scale--maybe Joe or someone can recall hearing of more. While I can p*** and moan all day over the lack of stock power (in my case), I think anyone is hard pressed to diss on the Cummins for its overall reliability (except for lift pump issues--).
Flu ridden Rogue
Gentlemen,
To those of you who took some degree of offense to my questions addressed to Mr. Williams, please be advised of the following. I have worked for a manufacturer of engines, compressors, turbochargers, etc. for 29 years. Most of that period has been involved in service-oriented positions ranging from field service representative to headquarters management. I know about engine failures and how they're investigated - I've been in charge of the groups that do the investigating!
[HUMOR]
The rule of thumb in the engine business is:
One failure - a fluke!
Two failures - a coincidence!
Three failures - a full-fledged epidemic!
[/HUMOR]
So, no, I wasn't having a cow or anything else. I'm just interested to know if we're looking at a fluke, coincidence or epidemic when the ISB is used in heavy towing applications!
If anyone thinks I meant any disrespect to Mr. Williams, please rest assured that was not my intent. I was just trying to understand the reasoning behind his questions - I know there is an underlying thought process going on because I've asked the same types of questions myself many times!
Rusty
To those of you who took some degree of offense to my questions addressed to Mr. Williams, please be advised of the following. I have worked for a manufacturer of engines, compressors, turbochargers, etc. for 29 years. Most of that period has been involved in service-oriented positions ranging from field service representative to headquarters management. I know about engine failures and how they're investigated - I've been in charge of the groups that do the investigating!
[HUMOR]
The rule of thumb in the engine business is:
One failure - a fluke!
Two failures - a coincidence!
Three failures - a full-fledged epidemic!
[/HUMOR]
So, no, I wasn't having a cow or anything else. I'm just interested to know if we're looking at a fluke, coincidence or epidemic when the ISB is used in heavy towing applications!
If anyone thinks I meant any disrespect to Mr. Williams, please rest assured that was not my intent. I was just trying to understand the reasoning behind his questions - I know there is an underlying thought process going on because I've asked the same types of questions myself many times!
Rusty
Last edited:
Thanks Pit Bull!!
amsoilman
Staff Alumni
Any engine can and does fail! This is a very isolated case, as most engines built today, including the mighty Cummins, will last a very long time if it is maintained and not abused.
As long as there are engines being built, there are going to be some failures. Why do we have so many automotive garages who repair engines on a daily basis?
When an engine fails, there are many, many things to look at to try and determine why it failed. In some cases one never finds out why it failed.
Someone asked "what kind of oil was he using?" Oil type or brand has nothing to do with engine failure. Oil is not going to make one part such as the #6 bearing in this case, fail. Now "lack" of oil could! If perhaps there were an oriface that was supplying the oil to this bearing were partialy clogged, or glogged, then it could make the bearing fail. Then one would have to dig in further to determine why it was clogged, or partialy glogged.
Like I said, engines do at times fail. The Cummins engine is of a superb design and is known as a very high quality, dependable engine. In many cases it will last hundreds of thousands of miles. But there are going to be isolated failures. Example: In the School district where I drive a Cummins powered "Bluebird" school bus, we recently had an engine throw a rod through the side of the block. The bus had less than 90,000 miles on it! Since new, it was driven daily by the same individual, and was serviced by our service dept. every 1,500 miles! When it failed, it was full of oil,(DELO)and had just been serviced (oil and filter changed) 400 miles prior to the engine failure. I can guarantee the oil did not cause this failure! Perhaps it was a manufacturing defect, or maybe someone when putting it together, failed to install something properly, who knows? It failed just the same, but it is very uncommon!
I firmly beleive in oil analysis! I think in the case of the School bus, if oil analysis had been done on a continuing basis, it could have showed something prior to the actual failure. Oil analysis when done on a continuing basis will set trends in the reports.
When trend analysis is used, as in the case of wear metals and certain contaminants, threshold values are developed to identify the boundary area between "normal" and "abnormal" results. For wear metals, these values vary for different types of component, but are specific and stable for each individual model of a given application. The values do not provide sharp lines of "normal" or "abnormal" interpretations; instead, they indicate ranges of increased likelihood that a problem has developed to a particular point.
Regardless of the threshold values, however, any sharp increase in wear metals or major shift in physical properties of the oil can signal beginning problems.
I'm positive if this had been done with the School bus situation, we could have avoided a major BREAK DOWN!
Wayne
amsoilman
As long as there are engines being built, there are going to be some failures. Why do we have so many automotive garages who repair engines on a daily basis?
When an engine fails, there are many, many things to look at to try and determine why it failed. In some cases one never finds out why it failed.
Someone asked "what kind of oil was he using?" Oil type or brand has nothing to do with engine failure. Oil is not going to make one part such as the #6 bearing in this case, fail. Now "lack" of oil could! If perhaps there were an oriface that was supplying the oil to this bearing were partialy clogged, or glogged, then it could make the bearing fail. Then one would have to dig in further to determine why it was clogged, or partialy glogged.
Like I said, engines do at times fail. The Cummins engine is of a superb design and is known as a very high quality, dependable engine. In many cases it will last hundreds of thousands of miles. But there are going to be isolated failures. Example: In the School district where I drive a Cummins powered "Bluebird" school bus, we recently had an engine throw a rod through the side of the block. The bus had less than 90,000 miles on it! Since new, it was driven daily by the same individual, and was serviced by our service dept. every 1,500 miles! When it failed, it was full of oil,(DELO)and had just been serviced (oil and filter changed) 400 miles prior to the engine failure. I can guarantee the oil did not cause this failure! Perhaps it was a manufacturing defect, or maybe someone when putting it together, failed to install something properly, who knows? It failed just the same, but it is very uncommon!
I firmly beleive in oil analysis! I think in the case of the School bus, if oil analysis had been done on a continuing basis, it could have showed something prior to the actual failure. Oil analysis when done on a continuing basis will set trends in the reports.
When trend analysis is used, as in the case of wear metals and certain contaminants, threshold values are developed to identify the boundary area between "normal" and "abnormal" results. For wear metals, these values vary for different types of component, but are specific and stable for each individual model of a given application. The values do not provide sharp lines of "normal" or "abnormal" interpretations; instead, they indicate ranges of increased likelihood that a problem has developed to a particular point.
Regardless of the threshold values, however, any sharp increase in wear metals or major shift in physical properties of the oil can signal beginning problems.
I'm positive if this had been done with the School bus situation, we could have avoided a major BREAK DOWN!
Wayne
amsoilman
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