I have a 3000 series Allison in my motorhome. When I changed the trans fluid in my motorhome I went on Allison's website and Mobil 1 Delvac synthetic trans fluid was on their approved list. I had also heard to only use the Transynd. I called Allison and spoke to a tech guy and he said use either Transynd or the Mobil 1. Anyone heard of any problems using Mobil 1?