Changing over to Transynd for Allison 3060R
I am about to drain and change my transmission filters (myself) for the first time. I'm also converting over to Transynd with a 131,000 miles on the coach. Purchased the filters and fluid from Stewart Stevenson in Albuquerque. The guy at the counter recommended changing the filters, filling the transmission, and then disconnecting the input cooling line from transmission, start the engine and letting the old fluid still in the system drain into a bucket until the new fluid starts to emerge, then yelling to person at the front to "turn it off." I am much more inclined to drain, replace filters, and put in Transynd and then change again at the "non synthetic" interval. He said that would be okay, but he prefers the other method.
What say you of more experience than I? I've read several posts here on the forum and it seems most go with change and change again. I can see me getting into a serious mess with the change, purge, and refill method.