Engine runs vehicle wont move Possible ring gear? 84 Topaz

I need to know how and why it was towed. Any and all AWD vehicles must be towed on a flatbed. If two wheels are left to spin on the ground. The drivetrain system will be damaged. If the vehicle was towed on a flatbed. I would need to see if the tow truck driver improperly installed their restraint chains and damaged something underneath. There is no way to provide you with an estimate. Unfortunately the vehicle needs to be towed to a capable repair shop or Dealer for diagnostics and estimate.

most of the time a clunk from under the vehicle when shifting gears (whether going forward or reverse) is a u-joint. check them at both ends of the drive shaft. (possibly 1 in the middle, not familiar with your particular truck)

Sounds as if forward driving gears are shot. Different gears make vehicle move in reverse. I would ask if transmission fluid level when checked is in the operation range or full.

Assuming that you have already ruled out the brakes, severely worn engine mounts can transmit vibration and noises from the engine which are not normally heard. You don't say in what I see but is the vehicle two or four wheel drive. Since you mention CV half shafts I have to assume it is at least front wheel drive. If the vehicle is four wheel drive then there is a front differential with bearings in it that may be at fault. Have you done both sides when you say "hub assembly". Defective hub bearings will make grinding noises which will change tone or intensity when turning, accelerating or braking however the noise is usually fairly constant unless they are only just starting to fail. CV joints don't normally "grind" unless they are really bad. They usually make progressively worse "clicking" sounds or "clunking" sounds especially when turning hard, changing gears or direction of travel (forward to reverse and back again). Do you have non-stock tires/wheels? Larger/wider than factory spec tire sizes can rub the fender wells when the car is moving or turning. Another thing it could possibly be is the air dam below the front bumper. If it is loose it will push down in the airstream while the car is moving and rub on the ground.

sounds like you have a busted drive shaft or a bust spigot shaft going into your gear box. Easiest way to check on this is to jack up the front of the vehicle and spin the wheels. If the drive shafts move then they are fine and you have a busted spigot shaft. The only way to replace this shaft is to drop the gear box and replace it.

Check the fluid to see if it is brownish vs reddish. If brownish, the transmission is overheating and mostlikely needs to be rebuilt. Good luck

your transmission is going bad, have it serviced immediately!!!!

clunking or grinding noises, wont accelerate to full potential,

I am sorry to have to tell you this but it sounds to me like your transmission is shot and will need a rebuild. If you can get it to a transmission shop they will tell you 100% what wrong with it. .