One year ago I crossed a 2ft deep river and a few months later my car has developed a few noises. One of these noises is a high and low pitch humming (oscillated noise) in the range of 35-60 mph. Before and after this range the noise cannot be heard. I must said that after the river crossing the right front wheel bearing cracked and it had to be replaced together with the front left wheel bearing.

After this river crossing I changed the oil of the following: gear box, transfer case, front and rear differential and greased again the drive shaft (propeller).

Mechanics are puzzled with this situation because they point it to many causes, example: rear wheel bearing, drive shaft, shaft crosses, exhaust pipe, gear box, etc.

I wonder if you could provide some insight into this problem or some ideas to start with. I will be very grateful