Loud noise i have a tahoe 2000 2wheel drive and it has a thunking sound when i drive it what could this be

"Thunking" is often a suspension issue. Possibly worn bushes, linkages or ball joints. Is it a single thunk as you first pull away or several thunks as you start to roll forwards?
The squealing brakes could be a separate issue. Ask a good mechanic to look at it and they can tell you what the problems are in more detail.

Not sounding to good. Sounds like you wiped out the planetary gears. Depending on the damage, your looking at $2000 rebuild.

if it is a 4 wheel drive sounds like your rear axle may have been cooked do to low fluid bad bearing or both check fluid level nad look for any kind of metal specs in fluid .

CK THE U JOINTS ON THE DRIVE SHSFT. YOU HAVE TO REMOVE THE SHAFT AND SEE IF THE JOINTS MOVE SMOOTHLY. IF NOT REPLACE THEM. ALSO CK THE CENTER SUPPORT BEARING IF IT HAS ONE. ALSO CK THE TRANS MOUNTAND THE FLUID LEVEL IN THE REAR END. HOPE THIS HELPS BILL

It is the rear motor mount. If there is a load on the motor it will make the noise and if there isnt any loud on it it wont make it. They should put a new one on it and maybe they could sell the car faster. There is three motor mounts on this car , one on the frount of the motor and one near the fan and another on the trans in back of the motor.

First let me say it is NEVER good to drive a car overheating , you can ruin very expensive parts.It hurts your engine and your wallet. If permanent damage has not all ready been done , have it towed to your trusted shop, it sounds like your water pump has failed

CHECK THE TENSION OF THE POWER STEERING BELT

Sounds like you already know what is wrong with it. It most likely needs a motor, or a rebuild.

My first guess would be the front u-joint on the drive shaft. Try twisting the u-joint to see if there is any play, which there shouldn't be. If the u-joint is OK, have the transmission checked out at a reputable shop. There could be a problem with the torque converter, the valve body, or the bands. You didn't say whether this was a 4 wheel drive or not, but I doubt that the problem is with the transfer case. Let me know what you find.

I am suspicious of your CV.