Is this normal? Trans related

The truck: 06 Tacoma 4x4 double cab short bed automatic. 62k miles.

Driving down the road if i let off the gas completely to coast it seems to engine brake 85% of the time for about 4-5 seconds. Never had that happen on any other Toyota or 4x4 I have had. At first I thought it was just the truck falling on its face but realized if I just keep my foot on the pedal ever so lightly for the 4-5 seconds it does not happen and have worked around it. My guess is its not normal but I always like to check before bothering the dealership.