Some old Pictures of a 3408 gernaded 651 hours after rebuild!

[kshansen]

I'm sure some here have heard the story on this engine and maybe a picture. I was looking at many old files on older computer and came across all the pictures I had taken at the time.

A little recap, local dealer did a major rebuild on this 3408 engine in a 769C at 13,737 hours. This was March of 2001, the following pictures were taken August of 2001 at 14,388 hours so 651 hours on rebuild. Operator was told by one or more people in the pit that something sounded bad in his engine. So as any operator will do he decided to drive it half a mile mostly up hill to the shop to tell someone, me! Well he got within maybe 500 feet of the shop when this happened!

Wrist pin in last picture was the one I found about one hundred feet back from where truck stopped it was next to the other connecting rod!

Cat dealer put the cause as failed connecting rod bearings as they said Cat had a run of them that de-laminated and this was probably one that slipped through the cracks and ended up in our engine. Don't think the pictures show it but the crank journals were not bad looking, other than a few good dents from hitting the rods on the way out. Not sure about the progression of a failed lamination of a rod bearing but would have expected obvious damage to the crank journal. But as they were eating the full cost other than down time did not seem to matter what the full story might have been.

Still would have been interesting to know what better information could have been discovered if driver had shut down the engine and used his CB to call for help. Engine would still probably needed to come out but a ton more parts would have been salvageable.

 

[lantraxco]

The usual dealer BS, looking for mother CAT to foot the bill... the crank journals would have been beat to crap and probably blued with the rods egged out before the made their exit, block left. Drive 'er til she drops, or as Doritos used to say "Go ahead, crunch 'em, we'll make more!"

 

[Truck Shop]

IMO- Fatigued rod or rods, rod bolts, piston and or piston cooler, rod bushing or bushings. If the crank journals were not toast then I would
expect one of the four. Maybe even a wrist pin lock.

But Cat does have it's flops. Had a cam seize in a C15 six years ago. Ran forty seconds. I was standing on the step of that truck watching the gauges when
forty seconds after start-up the engine started to pull down. I shut it off, couldn't bar it over. Pulled the front cam gear cover removed gear, engine turned
cam was seized. Cam on installation turned fine in head.
Found out next day Cat had a problem with a very slight swelling on the front bearing when they were installed in the reman heads. Not enough
oil clearance. Cat coughed up a another head, cam and gaskets. And even payed the labor. I don't know if Cummins would have done that.

Truck Shop

 

[John C.]

I saw many a Cummins B engine do that. Come to find out you have to replace all the rod bolts at overhaul. I've also seen rod caps that weren't stamped and got mismatched with other rods. Same kind of thing happens.

 

[Birken Vogt]

Found out next day Cat had a problem with a very slight swelling on the front bearing when they were installed in the reman heads. Not enough
oil clearance. Cat coughed up a another head, cam and gaskets. And even payed the labor. I don't know if Cummins would have done that.

Truck Shop

That is funny, around here the saying is exactly the opposite. The yellow ones would try to use any excuse to get out of warranty while the other guys would extend warranty without even asking it seemed.

I had a somewhat fresh reman turbo from Cummins that went bad for the second time, I thought it was outside of all warranty by then, ordered another rebuilt one, changed it, sent back the old one for core and the core refund was equal to the purchase price. So that was the way they handled warranty but I was out labor but it was not a hard job.

Another time we had one of the early Cummins DPF units, a bad batch of injectors caused the engine to eat itself, it was a bit outside warranty, needed a total inframe, we pointed out that it had been in a few times when it was under warranty for the same issue but it had just not gotten to that point yet. They responded by offering to cover 90% of the rebuild which we thought was great for a unit with some years and a lot of miles on it.

Experience with the C7 problem child was a lot different, boss blew a gasket on that one.

 

[kshansen]

Well on the one in these pictures I did not have the chance to see the engine apart, well other than like in the pictures. Not even sure if Cat bothered to take it apart or just pulled off the good bits and tossed the rest of it.

I don't think it was a rod failure as both rods were intact, one you can see in the pictures and the other that was on ground behind truck. In at least one picture you can see a broken rod bolt laying on the belly pan, makes me wonder if that was the real cause.

A little off topic rant below:

Often wish I had had a digital camera 20-30 years back to record some of the many failed things over the years. I know could have used an old fashioned film camera but the problem there is unless you took lots of pictures a week it might be weeks before you had enough on camera to send out to be developed and then if one important one did not come out right it was too late. Digital nowadays is cheap and you can see if the shot was any good in seconds.

Many times I have reached up inside a machine and taken several pictures in places I could not even get my head to see first hand. Then email a picture to the boss to show him where the problem was so he could know exactly what I was talking about with out both of us having to crawl up inside the machine. One example was the D9H that I worked on last winter that had the bolts missing or broken that held the transmission, he could see what I was telling him and he also was able to forward pictures to his boss who shipped the junk machine to us! Sure shut him up on telling us the machine was in great shape and ready to go to work!