3A. Next, the transmission pan was removed. The 4L80-E automatic tranny's gasket is reusable, so don't bother trying to buy a new one when you service your tranny. Most auto parts stores don't stock it and neither do most dealerships. We found this out the hard way, after running all over town trying to buy one because we assumed we needed it. | 
3B. |
4. We opted for a new K&N Performance Gold oil filter because frankly, they are easier to remove than most other brands and have a greater wall thickness and higher burst strength. Ever see a filter casing crack? You'd be surprised to see how far that oil can shoot. Besides, the impregnated cellulose filter medium offers maximum flow and excellent filtration. | 
5A. Pay attention now because this next tip will save your engine in the event of a valvetrain failure. We run a Filtermag on all of our engines because they work. It's exactly what you think it is: a high powered magnet for your oil filter that will make ferrous metals stick to the walls of the filter instead of trying to pass through the filter media. Should a mechanical failure occur within the engine, like a broken lifter or flattened cam lobe, the Filtermag will keep those pesky metal particles from entering the oil system and ending up in the bearings. Check out the photos if you want proof. Look at all of that metal debris trapped up against the wall of the filter where the Filtermag is positioned -- that debris came from a hydraulic roller lifter breaking. |
7. A 3/8-inch ratchet extension was used to remove the fill plug on the passenger side of the third member before it was filled with 4 pints of Royal Purple 75W-90 synthetic Max Gear oil. Note that Max Gear is formulated with hypoid friction modifiers for use in clutch- or cone-type rearends, so no additional additives are necessary. | 
8. Once the bottom end of the truck was buttoned up, we lowered the dually down on the ground and filled the engine crankcase with 7 quarts of 10W-30 synthetic oil and the transmission with 3.5 pints of ATF. |