I am having some issues with my 03 Explorer. There is a chattering noise when I eccelerate from a stop or hit the gas when going down the road? Are these truck known for transfer case problems? I can feel the chatter too, I had one guy tell me its the chain slipping in the case? Another told me its the 4x4 shift solenoid not engaging all the way?And to top it off I had new tires put on the front, now there is a grinding noise! I checked the brake pads, they look good? Any help would be greatly appriciated.

 

Did you remove the wheels to check the pads? That's the only right way to check them because one pad will usually wear more than the other, also look at the rotors themselves , both sides inner and outer. If a pad is cutting into the rotor you will be able to see the grinding marks on the rotor. It should be smooth on the inside and outside.
Do you have locking hubs that were left in the locked position? Do you get this grinding noise only when you step on the brake or all the time?
How about the chatter when you have it in 4 wheel drive, and low?
There are so many questions that need to be answered.

 

I had the wheels off to inspect the brake pads and rotors. All is good there. The chattering noise does go away when the truck is put into 4wheel drive, which makes me believe its in the transfer case?