Cummins ISX crankshaft bearings? (2024)

Hello guys,
I have a 2005 volvo with cummins ISX engine which has 1040000.00 miles on it.Friends told me that i should consider replacing the crankshaft bearings since the truck is ove 800k miles and recommend by cummins to do sther people said dont even bother if your oil pressure not droping.The oil pressure stay on 35-40,just when outside is above 90F and when is about to oil change then keep it close to 30but i think that's normal.So what do you think should i replace them or...?

Oil ck. up by sending a sample of oil before you change it will tell you the condition of bearings after a few samples you will see readings of how much the eng. is wearing, kit can be bought at truck parts stores.

Are you talking about the oil analys that they do in speedco.I do it once every other oil change and everything is normal acording to the analys

I would def do the main and rod bearings. It's an inexpensive thing that will save you a lot of cash. If they go it will wipe the crank out. Motor can still have great oil pressure but have bad main and rod bearings. With that many miles why take the chance?

Could u explain what exactly the main and rod bearings are if u don't mind for some of us on the forums that are still learning their truck?

Thanks in advance.

Main and rod bearings are the bearings on the crankshaft. The ones that are attached to the piston rods are the rod bearings. They are the smaller ones, the bearings that are located wear the crankshaft bolts to the block are the main bearings. The reason that you do both sets when you do the job is because you want all the bearings to wear evenly and equally together. Plus since your already there it makes sense financially to do both. The bearings themselves are very inexpensive as far as motor parts go, but they are a vital part of lubrication for the motor. Although the bearings are inexpensive they can cost you big dollars if they fail or wear out. So it's important to keep them fresh. I've always changed main and rod bearings out between 800k and 1 million miles. Or if you do a engine overhaul. The hardest part about these bearings is that you can't see how they are wearing without physically taking them out, looking at them and mic them.

Your probably looking at an inframe pretty quick. If you have not done rod and mains are a
Must . Your probably in the copper at least a little at a million miles plus. A cat 3406 is due for rods and mains, well I've seen them to start In the copper at 650,000 miles.

Yeah at a million miles she's getting tired, not even thinking about hours idleing. Even if you have a apu its a lot. The engines have gone full circle, even the cummins. Isx only has one head just like the old 3406 dita cat. One head so if you get one hole hot a new or rebuilt head is due. Look how hot these new engines have to run to pass emissions. Fans don't even come on till 195 degrees. If your pulling a hill and its 100 degrees outside, not good.

THANK U VERY MUCH! That was very helpful, I'm glad I know this now. I snapped a photo of this on my phone and will continue to reread it! Thanks

Thank you all.Very helpful info