Bearing gone but which one
 

Hi all have a bearing which has gone,first i thought it was the diff in the gearbox.I changed gearbox oil and found that the gearbox sump plug was covered in metal filings,but also was working on the car at the weekend,and found that the drivers side driveshaft rubber boot nearest the gearbox had split very bad,and that the grease from within the boot had come out.

the car has been making a whining noise under deceleration,for a while,just wondered whether the driveshaft could be the problem,or whether it is more likely to be the front diff ?

any help would be much appreciated !!!!