Can anyone please help me out. I have a 1997 Cadillac Eldorado ETC Model with 124k, drives beautiful and looks great. The rear driver side under the wheel is making an old bed spring noise when I load or unload anything into the vehicle. It makes the sqeaking noise just hitting little bumps in the road to.. It's driving me crazy!!!
I put the vehicle up on a lift and tried to locate exactly where the sound is coming from. It sounds like it's right behind the rotor or right next to the strut and shock. I cannot pin point it. I have greased and sprayed WD40 on every single joint in that rear section and it goes away for 10 minutes of driving then comes back.. Someone told me to drill 3/32 inch holes in the back of the joints where the upper and lower control arm meet behind the rotor and grease it up? Please help anyone.

Also, My rear (passenger) brake is making this screeching noise when I hit the brake. I have taken the pads off and they still have 70% left on them. The rotors are in mint condition. I purchased brake spray and sprayed the whole inside area down and even washed everything in there and it still will not stop, even took it to a mechanic and they can't figure it out..

My beautiful 97 Eldorado sounds like a 18 ft tractor trailor coming to a emergency stop.... please help..!!!!!!!!!!!!!!!!!!!!!!!!