rafferl....Just some added info. Your ISL has two drain plugs, one is just above the other. It allows you to drain some of the 24+ qts and then drain the rest. You have a couple of grease fittings on each side of the axle(s) near the brake air cans that are sometimes missed. You also have two on the u-joint where the driveshaft connects to the rear end. Either will fill the entire u-joint. There is one fitting on the slip joint of the drive shaft. When filling this one, you need to place your finger at the rear of the slip joint (between the u-joint and slip joint) where you'll feel a hole at the center of the pipe. Place your finger over the hole while filling the slip joint fitting. This will prevent the grease from pumping out the back of the slip joint. The front fittings are fairly easy to locate, but there are three on the steering column. One is obvious, (down low) one is harder to find about half way up and the third one requires that you pull the housing off of the steering column inside the coach.
Because of the torque these things produce, they recommend that the driveshaft be lubed every 5000 miles.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor