While cruising I hear a pulsating huming sound from under car. I think it might be drive shaft related but I dont know. Any help would be appreciated. I looked under the car and around the ujoint area there is splaskes of oil or grease. If that helps.

 

*splashes

 

That's signs of an oil leak coming from either the transmission or rear end. Get it to a shop ASAP for proper diagnoses.