I just bought a 2001 2500HD 8.0L with an allison transmission with 140K miles. I was wanting to change the trans fluid and external spin off filter. I have been told that the internal filter does not need to be changed unless the tranny is being rebuilt. Do I need to change the internal filter also or can I just change the spin off filter and fluid. Also can I have any steps to changing if possible and also what fluid is best and how much does it need in qts or gallons. Any thoughts or opinions would be appreciated. Thanks!

 

hows it going lilrock?

well if you go to this page @ the bottom it has a section called my allison,it has maint section per your application...

http://www.allisontransmission.com/index.jsp