Last year, I put synthetic fluid in my Allison six speed and it ran great. Some folks said to change it again to make sure all the old fluid is gone. I had it professionally flushed and changed the first time. Should I have it done again?

quote:

synthetic fluid in my Allison six speed

of interest??

http://www.beamalarm.com/Docum...change-interval.html

If an Allison shop did the work you shouldn't have to touch it until it is time to change it again, as they should have done a complete flush and changed the filters. If somebody else did it i would ask them exactly what they did and go from there.

The reason for the redo is the torque converter. There is no drain plug on the converter so there remains some of the old oil.