Main bearrings?

[Bill5811]

I believe I have a problem with the main bearings. I have a knock coming from under the truck, rather a loud hard knock, last night I took a piece of hose and tried to isolate the noise, it seems to be loudest at the oil pan flange right next to the oil filter and somewhat quieter on the opposite side near the starter. Since this is right by the main I assume this is going to be the problem. The truck has less than 60k on it but was used hard towing.

Is it possible to remove the pan and inspect / replace the mains from underneath or do I need to pull the engine and disassemble? Anyone have any experience or advice?

[TAZZ9963]

well, I just pulled my pan in chasis this spring for a #7 ring change and it wasn't easy. I had to jack the engine to it's max and unbolt and move (not much) the front differential, that's if it's a 4x4 to have enough room to drop the pan. the oil cooler lines are also in the way but I was replacing mine anyways so it made it a bit easier. Oh yea I also had both heads off so there wasn't much in the way on the upper half of the engine, I don't know what kind of clearence there would be with all that stuff on. good luck if that's the problem.

[grancito]

main bearings don't knock, you could be hearing a bearing knock from the piston on the opposite side of the engine, or an injector problem from that same cylinder. when I say from a piston I mean big end bearing, or gudgeon which is unlikely.