A big part of keeping us on the road is making sure that we service the fluids in the truck according to the recommended change schedule. We have a 3500 Chevy with the Duramax engine and Allison Transmission. For the oil and transmission fluid changes we use Mobil 1 products.
We change our oil every 5,000 miles. And, what we have noticed is that in 5,000 miles the temperature and type of driving (towing, mountainous, flats, etc.) can change drastically. The Mobil 1 oil is rated for a wide range of temperatures and conditions including under heavy loads. It also meets the CJ-4 requirement of our truck. Regardless of the additional benefits provided by the Mobil 1 oil we use the most important thing is to make sure that at the recommended change schedule the oil is exchanged with oil from any reputable company as long as it meets the OEM requirements for the engine. When your vehicle moves your home, it is important that it continues to operate and is even given some extra attention. Learning how to do simple maintenance on your vehicle is the most cost-effective option keeping money in your pocket for other expenses and allowing you to become more familiar with your vehicle. However, sometimes paying a shop to do maintenance and repairs is the only option.
The Allison 1000 transmission is equipped with a spin on filter and a drain plug. In order to do this change we drain roughly 7 quarts out of the transmission and change the filter. This does not drain all of the transmission fluid out of the system. We add new ATF to the system and that will mix with the old fluid extending the life of the oil. Some call this the hoop method. We do end up using more oil this way. The reason for doing it this way is that we can change the fluid ourselves on the road as opposed to taking it to a shop. So, even with the increased cost of ATF we save by not paying labor for someone else to work on the truck. This is not a recommended practice. We considered the age of our truck and the number of miles left in our drive train before deciding to use this method.