1994 Ramvan 250rear end noise

[mgrund]

My van has 95000mi on it and I heard a bang under a light load around 40mph and I hear a thunking noise from the rear. It sounds like a stick in the spoke of a bicycle wheel. It gets faster with the speed of the vehicle and quits if I let off of the gas. Please help. There is no clunking from the UJ when put into gear and it does not make the noise in reverse.

[Dodgevanman]

Sounds like you may have chipped or broken a tooth on either the ring gear or pinion gear in the rear diff. I'd get it checked out ASAP.