I had zero warning when the transmission went out on my Suburban. Rolled up to a stoplight in Kremmling, stopped, when the light turned green the engine just revved, no movement.

The "good" news was that I only lost gears 3 and 4. 1st and 2nd still worked so I was able to "limp" home in 2nd. Which was good because I was pulling a trailer and had the wife, the dog, the trailer and 2 kayaks, plus all our camping gear, to get home.