Being a first-time diesel owner [2013 Chevy Duramax/Allison 2500HD], I saw 215* for tranny temp on my Bullydog tuner. Not knowing the max temp, it scared the hell out of me. We were pulling up a 6%-14% grade with very little relief and no pullover sites. Had me sweating big time! Called my dealer and he told me about the warning coming on at 250*. Until that time, I didn't even know about a warning, much less the max temp. Never saw it in the manual and I read that thing cover to cover several times.
It generally runs around 155-175 on low hills and flat land.
2013 Silverado 2500 HD Duramax/Allison Tuned
Aviator Wright Flyer #1919
"First In, Last Out". 11B4Y
DAV, MOPH, VFW, 5/7 Cav,1/8 Cav Assoc.
11th ABN Pathfinder Co. N7MIP