Fire Up,
No disrespect meant, but if you re-read my first post on this topic, you will see that I am not changing over to Transynd. I am already running Transynd. My quandary is whether to change out all the Transynd at 90K miles, or only do a filter change and top off the lost Transynd and perform an oil analysi. Or, just change the filters and all the Transynd, and not worry about it for another few years. My prognostics tell me that neither is due right now, OL 78% OF ok, but Allison states that on MHs you can't go by the prognostics, as we don't run a heavy enough of a duty cycle for the prognostics to be accurate. My last and final question is how much fluid do you lose only doing a filter change? If it is a couple of gallons, then the difference to replacing all the fluid is really not too much more.