Many Diesel Engines are bolted to an Allison Transmission for reliable automatic shifting and doing proper services to the transmission is a great way to make sure the transmission runs without too many problems. This video goes into detail about how to properly drain, refill, and change the filters on the 3000 and 4000 series of Allison transmissions with 2" and 4" sumps. Donations to the channel can be made to [email protected] on Paypal.