If you are replacing the oil pan in your '89-'02 Dodge Turbo Diesel truck without removing the engine, you need to unbolt the oil pick-up tube to allow removal of the oil pan.
When you go to reinstall the oil pick-up tube, install a new gasket.
NOTE: Removing the oil pan is big job and can be dangerous if not done with the proper precautions. A search of the internet will provide information of how truck owners have done this job.
Replaces Mopar 5010479AA, 5010479AB and Cummins 3900454, 3905468, 3914383, 3931349