Cummins N14+ cam shaft.

Sounds like fun, for the for the first hour maybe. Trucks are definitely nicer to work on than about anything else I've ever worked on.

 

Man, that sucks to hear.

 

One quick way to check if you have a bad/worn lobe on cam or the roller on cam box is when you pull the valve covers, if all the valves & injectors are properly adjusted then look at the adjustor lock nut & compare the height of each one, they should all be very similar. If there is a worn lobe then you will be able to see more threads on the adj set screw. To replace the camshaft you will need to pull the valve covers, Jake's if you have them, the rockers, push tubes, the fuel pump, air compressor, accessory drive, p/s pump, oil pump, ecm, starter, get all wiring, hoses out of way to remove the cam boxes. If you have 1 bad roller you know of then you may have more, plus you can check to see if they all roll good, no bearings going out. You can replace the rollers themselves. Will need to know what thickness gaskets are behind the cam boxes for timing purposes, never use silicone on them & all 3 will use the same thickness gaskets. You will also need to pull the Rad/CAC, crank dampner, fan, accessory drive pulley, alternator (ususually just bracket the has 1 bolt on front gear cover), drop the oil pan, use a bottle jack to raise the engine slightly, remove the front mount & the gear cover. There is also a cam support that is hrld on gear cover w 3 bolts that is shimmed, that will need to be reshimed w the new cam. I would also replace the rod & main bearings & the oil cooler, filters. Yes its somewhat of alot of work but in sure in the hell beats spending $10,000 +.

 

Where did you have it OH ? Even tho on a basic OH N14 you don't pull the cam, cam boxes they should of at least inspected & advised you of any wear. Most of the time when a N14 has cam problems it is because of lack of maintenance, something got into the oil (they were not very clean) when doing the OH, the adjustments were not set right. Unfortunately I have seen guys Not reset the Valves and Injectors after pulling up the rockers to replace injector(s), they would just impact the bolts back down. I personally HATE it. EVERY TIME I pull a set or sets of rockers I will retorque & reset my lash. .014 Intake. 027 Exhaust in Most Cummins. Thats my name & reputation on that repair. Or may not of had the push tube all the way in the cup of the roller (can bend a tube) or debris in the cup when they put the push tubes back in during the OH. When it comes to especially engine work it is imperative to be clean, prep is one the most important parts of repairs, rebuilding

 

Who knows with these cams anymore , I had 2012 isx inframed at 684k and the cam looked like I had dragged it behind the truck for 684k so new cam and rollers...all Cummins parts .
At 228k last month opened it up for an overhead and had 1 bad lobe and roller so now I have another new cam , bearings and updated rollers .
Of course Cummins offered me their deepest sympathys and wished me better luck this time .
Oil was always changed in the low 20s up until shortly before the latest issue I had switched to full synthetic.
Rarely idled for more than warm ups and cool downs .
Ironically the fleet I'm leased also had a rash of isx cam issues at the same time , initially Cummins wanted to blame it on our oil supplier but finally admitted they are still having cam issues .

 

I used to do a lot of NTC engines. My job they called the dish washer. I cleaned everything up and did all the dirty work. Also got to pull the torque wrench. Cylinder problems were more common than cams to us but they both put metal in the oil. The filter is supposed to catch anything large enough to damage the engine unless it is stopped up. Then a bypass may allow unfiltered oil into the system.
We used to replace crank bearings at about 350,000 miles. That was on a schedule just like changing oil. They normally showed some copper.
Some lines worn in a journal is not to big of a concern. If the other 98% is good. Crank is supposed to ride on a film of oil and never touch the bearings anyway.
If metal went all through the engine why are the cam bearings good?
Somewhere along the lines I graduated from washing dishes and a 444 comes to mind. The crank was pretty rough but rods miched Ok and mains plastigaged OK. Explained that to the owner but we can hand polish the crank in the block and it will be OK. You just need to put bearings in it every 300,000 miles. That was on my opinion and he said to do that. This truck was towed back and the owner was there at the time. It had a bad rod. I was apologizing telling I thought it would be OK. He told me " You told me to have the bearings replaced every 300,000 miles. It has 575,000 on it since you worked on it and I never had that done. It was running hot and I was in a bind. in traffic, loaded and I ran it to the next exit."
Old men from the 2nd great war probably taught most of that kind of stuff. Of how to do a lot with little.
Changing the oil in a truck it had all kinds of clumps a stuff dropping out. Called the owner. Oh: The overhead cam went out but they replaced it under warranty. They did not even change the oil? No: They said it would be OK and don't worry about it. ( this was not a Cummins )
It is sometimes interesting what is OK depending on who is paying for it.