another question new noise

I just took my jeep offroading today for the first time in a while. I finally fixed the control arm bracket and the angry sparrow noise, but unfortunatly after cleaning the jeep off from today i have a new noise. Everytime I take off i hear a banging sound like to metal pieces hitting eachother. This only occurs once and the jeep drives fine, but everytime i stop angain and take off i hear this bang just once. any ideas unfortunatly i cant go look at it due to this damn storm were having.