Whining p38

Hello , i have a 96 p38 4.0 its only covered 83000 miles,...over the last few weeks its developed a whining noise , at first it only seemed a light whining from around 50mph, only noticed under light acceleration, however over the last few days the noise has increased,... which is more noticeible,and the faster you go the the whining increases with speed , when you take your foot off the gass you can here the whining decrease with speed also, i have look at previous threads to no avail, gear box still seems smooth , i cant pin point the noise from in side the car , (so that rules out the better half)so not 100% what it could be , but also thinking it could be wheel bearing???? however the noise dose not change when transfering load from one side to the other , but this could be down to sheer weight of the rr, are their common issues with the box /t box diff ect that could cause this????
any help would be great,....Thanks Rob

Front or rear diff?

mine was the rear diff,had it for weeks ,couldnt fint till rear diff started banging,by the way there a pain in the a****** to do ,you have to take the axle ends of to get the half shafts out,make sure you get new oil seals+dont feck about cut the bolts of and get new ones,the diff bolts come of fairly easywith a dose of plus gas ect,its heavy so be prepared.....best of luck ...dave

Had a whining noise on my P38 when it had done 52000. Turned out to be a bearing in the transfer box, Had a recon box fitted by Ashcroft has been fine since and car has done 120k