need some help i just turned 18 i bought this ford explorer realy cheap. when i accelerate the rear end knocks i have heard that it could be my transfer case and i have heard that it could be my rear in going out. i dont know which one to test first. i dont wanna be putting massive bucks into this becuase i only have a job at best buy and get paid minnimum. if any one could help me out itd be appreciated. it doesnt start popping untill i put it in drive then it will pop when im stoping when im accelerating it does it alot. somebody please help me out give me some ideas on where to start.

 

Does the noise seem to increase with road speed and does it change when turning? Is it a 4 wheel drive? If not a 4WD, then not a transfer case. I would look at the universal joints in the driveshaft to see if they are loose and need replacing. Is is a loud noise, or more of a squeak type rotational noise? A few more particulars on the vehicle would help.

 

Yeah the intensity of the the noise increases at road speads. The car is 4 wheel drive. But I took it out today and when I drove it the transmission slipped and yesterday when I changed the mass air flow we were having problems putting it in reverse. Today was the first time its ever done it in drive. Could the whole cause be a problem with my transmission.