Mike, my '03 Monterey came with Transynd, and there was a small tag placed in a ziplock that was tie wrapped to the dipstick tube to inform the owner that the transmission was delivered from Allison with Transynd. As Gerald stated it may have been delivered with Dexron and is due to be changed regardless of the type of fluid due, to the time in service (years). It would be prudent on your part to confirm which type you have, as you surely don't want to put Dexron in a transmission that has been seviced with Transynd. I had mine changed in '07 by a certified Allison shop, and it cost around $415. Good luck!