Front drive shaft has a bad grinding noise and the rear seal has cracked and the bearings are exposed and all the grease has leaked out. do i need to replace the entire shaft and what is the diffuculty and cost of doing so.

Maybe Tires or wheel bearings.

if this is a 4wd drive model , try having someone listen to front wheel hubs when you back up , id be conserned that the front wheel hubs seals have gone bad and there is now dirt inside bearings and has damaged them , also ive seen clicking caused by locking hubs not fully disengauged by dirt stuck inside

This due to either a worn wheel bearing or a worn front drive arm.

The most common cause of a grinding noise when turning is a worn front wheel bearing. What happens is that the weight of the car is shifted on to that wheel as you make the turn causing the worn bearing to make a grinding noise.

Check the oil level ,if need be pump some LM grease into the gearbox about a GREASE GUN FULL will do this will seal up any leaks once its warm and melts in a bit ,the noise was the lay shaft bearings or the drive gear shaft bearings to the crownwheel ,faily common on peugeots and citreons but make sure you check the level use EP90

You need a new drive axel before it messes up your trany.Do to the coplexiity of this job get a book I could speend an hour explaning it to you

SOUND LIKE WORN DRIVE SHAFT BEARINGS AND A LEAKING DIFFERENTIAL PINION FLANGE SEAL.

Hello, You may have damaged a bearing if you discovered the seals were leaking it may have dropped the axle lube too low to protect the bearings. When you were removing the wheel seal, you must have exposed the rear Emergency brakes on the 1 side you replaced the wheel seal on. You should have observed the condition of the part. The other wheel may have the Emergency brake dragging and making the noise you continue to hear.

A lot of times the lining from the E brakes will separate and fall into the drum/rotor. Then it will jam or grind until it is dust. While you worked on the differential was the driveshaft inspected for bad u-joints? Check the drive shaft joints while you are under the car.

You still may have a bad bearing on the opposite wheel you worked on. You may need to put the car on a lift and have a helper put it in gear. Be careful for long hair, loose clothes, etc and you can just take it easy on the speed you run it at.

the leak is probably a separate issue from the noise. is the leak very bad? can you tell if it's engine oil or transmission lube/fluid? most likely the rear main bearing seal needs replacing. the noise is most likely the clutch release bearing. you should replace all components of the clutch assembly which include; clutch plate, pressure plate, release bearing and piolot bearing. also have the fly wheel resurfaced. while the trans is out, you can check the rear main seal and the trans input shaft seal and replace accordingly.

maybe it was he drive shaft ujoint or the wheel bearing that went out.
did the ring and pinion look bad, You have three bearing in the rearnd. did you replace any ??

if it's a 4x4 you need to replce the axle on drivers side