[Bactrian]

Hi-
Do any of you know the service intervals for the main and rod bearings for the Cummins 5.9l 12v? I have heard they should be rolled out every two hundred thousand miles? And has anyone performed the task of rolling out bearing while the engine is still in cab? I have heard of the cotter pin technique, but never tried it myself. I will have the pan and front cover off the truck next week and i'm debating if should just put some new bearings in along with the colt cam and new tappets. Factory bearings are actually pretty reasonably priced 120 for mains and 117 for rods, standard size of course. My rig is about 240,000 on the odometer currently, so i guess i am a bit over due for the bearings and a head gasket? any advice would be appreciated! thanks in advance.

 

[GAmes]

I have heard they should be rolled out every two hundred thousand miles?

That is the most ridiculous thing I have ever read concerning this engine, or any other engine for that matter.

 

[Bactrian]

I read it in the Cummins service shop manual, I'm not just fabricating false information. It is based on the amount mileage you put on the engine in a given time period. I am going to do it, I put over 65,000 in a years period during 2013 moving freight. I figure if i have every thing apart might as well replace as much stuff as possible.

 

[dauntless89]

I rolled bottom-end bearings into a rattling 22r once. Not the "correct" way to tighten up the bottom end but solidly worth the 3 hours it took.

I have seen other posts where people said they did it. Gotta lift the front of the engine enough that you can get the pan off, and make sure you can get your torque wrench on all the necessary bolts before you start taking stuff apart.

 

[GAmes]

I read it in the Cummins service shop manual, I'm not just fabricating false information.

The Cummins service shop manual says to inspect or replace them every 200,000 miles? I don't believe it. How do you explain the million mile Dodges that have never been opened up, or mine with 800,000 when it needed a rebuild? ONE, count it, one...... rod insert was down to the brass.

 

[dauntless89]

Although I will say, GAmes has a point. We need to get away from this notion that things like bearings, head gaskets, injectors, etc need to be replaced at regular intervals like oil and filters are. These engines were designed as a medium-duty truck engine for use in vehicles/equipment with up to a 66,000 lb GVWR.

Do you think the customers of said equipment would be happy if they found out after purchasing the engine that these major/basic components needed service at relatively short intervals? I wouldn't be.

 

[1070]

we used to change bearings every 200,000 miles back in the day with the old ntc 250 in big trucks, it was a common practice then, but I have not heard of it in a long time, was this recommended in a b series engine or one of the older ones.

 

[Donotrespond]

That is the most ridiculous thing I have ever read concerning this engine, or any other engine for that matter.

It's called a bearing roll and it's something that was done on a regular interval on older diesel engines

 

[Donotrespond]

I rolled bottom-end bearings into a rattling 22r once. Not the "correct" way to tighten up the bottom end but solidly worth the 3 hours it took.

I have seen other posts where people said they did it. Gotta lift the front of the engine enough that you can get the pan off, and make sure you can get your torque wrench on all the necessary bolts before you start taking stuff apart.

Small world because that's my first roll as well at 22 yrs old sometimeagonow but brought oil pressure right back to almost perfect.