I am new to the diesel world having just purchased my first diesel truck on 04/18. I am going to switch over to all amsoil, front and rear diff,transfer case,manual transmission and engine oil. I will also be putting in the oil by system. I have a few Amsoil dealers in my area, none that I have done any business with, so I would just like to know what oil I should use in each place just in case the person I go to is not the sharpest tool in the shed. The truck has 26000 miles on it. I will towing between 13000 and 15000 total weight 1 or 2 times a month. Not sure yet if has limited slip. So far I can say.... I dont think I will ever by a gas truck again!!! Thanks again, and thanks to all the great info on this site as I have spent a great deal of time reading old posts. GSHARK. :thumbsup