Why do I hear grinding noises while driving?

Sorry to say it sounds like you have a bent axle, If you mean Drive shaft when you say propeller shaft, then that's either because you also bent the driveshaft or you have u-joints that have gone bad. It sounds like a mess, Did you hit something or run over something? Rear axle don't just get bent form nothing. Has there been a grinding noise for awhile coming from the rear area? Your axle bearing or wheel hub bearing may be shot causing the wobble,

A grinding noise suggests a bearing at fault or perhaps worn pads on the brake rotor.

However, the clunking noise you mention could also point to a problem with the drive shaft or differential.

The first thing you should do is to get under the vehicle and try twisting the propshaft back and forth. If there's any movement this points towards a worn universal joint on the propshaft. A worn universal joint can cause a clunking noise - particularly when pulling away. The vibration caused by a worn universal joint can also damage bearings in the differential and also to the splined ends of the axle shaft.

You're also going to have to remove the wheel from where the noise comes from and examine the end of the axle shaft/bearing.

The link below is of images of the rear axle:

land rover discovery rear axle Google Search

I believe that your Subaru has a transmission issue. There are quite a few things that will make a grinding noise. Wheel bearings, worn out brakes, damaged brake rotors or drums, loose or damaged brake calipers, defective hardware kit (for the brake shoes), torque converter, flywheel, U-joints, and CV joints. The interesting part of your symptoms is that you can only hear the grinding between 30-60MPH. I think you need to continue testing and inspecting components, one by one. You have all ready narrowed your search down. You know that the Brakes, CV joints, and Bearings are fine. So now you need to focus on the drive train. Inspect as much as you can from the flywheel, to the transmission, the drive shaft and rear axel, and the output shaft and front drive axel. If you can not find it yourself it may be time to send it in for repair. Let me know if you have any questions or new information, good luck.

This is one of them questions and need i say more ,as without looking myself and having a drive then i could tell you straight away iam sure ,because without hearing the noise i cannot even summise where or what it is because a grinding noise is -well -difficult to denominate exacty what one defines as a grinding noise ,myself i would define it as a rythmic noise with the road speed but someone else would call it that noise for a trailing arm bush loose or worn but one thing to check is are the pads hitting a part of the brake disk thats corroded like on the edge of the brake disk ,sorry to be absolutely no help at all but i hope you appreciate how difficult it is to diagnose something with hearing it and from afar ,but if you only hear the noise when on a rough road could it be the tyres like a deformed tyre or them town and country tyres with big chunky treads .

That roaring noise should be a wheel bearing. Jack up the rear wheels and spin the tires by hand. You can hear a grinding noise if the noise inside the car is as load as you state.. The only other noise that will be like that is the differental gears inside the drive axle

I would investigate the transfer case. By your description here it sounds as if the gears inside are worn and the drive chain inside is rubbing, causing the loud noise you hear.

You can do this job your self with common tools. Auto zone carries the wheel bearing you need and can give you the step by step instructions to replacing the bearing. Here is a tip, to try to break the old wheel bearing from the axle. Just loosen the 4 bolts 3 mm that hold the bearing to the axle and put the wheel back on and drive the car back and forth a few times, hard on the brakes to break it free from the axle. Once the bearing breaks free from the axle, it should take you under 45 min to get the job done. Good luck and be safe.

make sure you have the right size axle.if too small it will make grinding noise you will round out it gears and the internal gear it goes in.

sounds like c/v axles (front drive shafts) they will make a clicking sound normally when turning sharp and accell at the same time at slow speeds / look at the axle boots and look for grease on the inside of the front wheels leaking out the axle boots

try putting oil in ur rear axle