When do you do Rods and Mains? How about inframe?

He said his engine is a n-14 they have one bearing that needs to be changed if not you will take out the crank. This is from experience and Knowledge.Like I said earlier this is the wrong place to ask that question.............

 

I'm sorry I read C-15. Why would this not be the place to ask, just wondering.

 

Again as always, heavyd nails it. Listen to this guy, bar none one of the most knowledgable guys on this forum.
The bottom ends on everything after the b model cats go a million no problem. Unless you got something else going on as stated.

 

Most late model stuff I have torn down the rods and mains look good with 800 to a million miles. The top half of the rod bearing always wears more than the bottom half. The M11 and N14 celect plus are about the last ones I have seen drop oil pressure gradually as the rods wear the top half. Have seen several so bad they will lose all oil pressure idling. Top of the rods will be down to brass every thing else will look good. I have seen cranks egg but usually from a spun bearing. Course using plastiguage and a micrometer is a lost art or waste of time some say during an overhaul. Just like tearing an oil pump down to check it. As with any thing the wrong hand in the bottom of your engine can cost you way more than if you had run it. Rule of thumb here is if oil pressure is good at start up but losses oil pressure as it warms up you have slack some where. 10 to 15 pounds difference normal but much more is slack in bearings either rods, mains, or cam. A bad pump or pickup tube will do similar but oil pressure will be lower than normal at start up and be at 10 psi or less before stats open.

 

I did rods and mains at 984,000 on my C15 because the average oil pressure came down 5psi, starting around 960,000 and there was some flutter with the gauge that it never had before. The oil pressure was still above spec but down to 58-60psi at 1,000 rpms fast idle compared to 63-65psi that it used to be at. Also driving down the highway it was 5 psi lower than normal. Some of them did have some wear thru the first layer but they could have lasted a lot longer if left in is what I was told, they were fine... Hindsight is always 20-20 but in my case replacing rods and mains turned out to be a complete waste of time and money as the motor had to be inframed a little over a year later with 1,111,000 on the clock. I will never do rods and mains on a million mile motor again, live and learn... As others have pointed out, and I agree, don't do it keep that money - expect and get ready to inframe instead. Just my O.

 

CAT's recomended overhaul guidelines are: 600,000+ miles or 120,000 gallons of fuel burned or 12,000 hours (which ever occurs first)

 

Weather they need it or not, I Bet

 

Doing a bearing roll in takes a total of 4 hours to do, it alows you to not only change the bearings but check the cam and cam boxes, for damage, If you are a flatlander and pull smaller loads, you can extend the milage. Like I said before, spending money on oil samples to me is 100% BS, If the cam flake off it will not tell you if a cam box shaft breaks it will not tell you, if the roller on the cam box breakes down it will not tell you.
If you clean the air filter canister every time you look at it, and inspect the intake piping you will not suck in dust.
If when you do the bearing roll in you find the caps fretting many times it will be ok if torqued properly, leave it loose and you will have a piece of junk.
Maintanance saves you money, waiting because some piin head tells you it is not needed can cost you a lot of money, down time, and posibly you job, over less than a grand.
Just a thought!

 

I bet if you really tried you could do it 2.5 hours!