Whirring from transmission area (not T-box Whine)

Had this noise for several months now, only when engine is under a certain type of load. I thought for a while it was the exhaust vibrating on the chassis or something cus it resembles that sort of sound. After checking a few things i found an oil trace and small drip from the front oil seal of my transfer box.

Im thinking the noise could be crap thats gotten in the drive flange, hence noise under load and the minor oil leak.

Does this sound about right?

How hard is the various gubbins that may need replacing to sort?

Cheers

the silencer box has more than one layer of thin tin ,these often vibrate together when under load all mine have at some times but nothing visible from outside,if you think its front remove front prop and try it in diff lock this will take torque off front output

Trust you`ve checked oil levels in both main box an transfer box? If a manual box is the noise there when engine running in neutral? does it change if you dip the clutch, or only when moving? Under load or on aver-run?

Where the noise is coming from i have a new exhaust section so i dont think it would be that.

Main gear box i did the oil not too long ago, not the T-box though so that is a possibility.

The noise mainly occurs on acceleration but also when just cruising in 5th (high speed)

exhaust or shield vibration noise is totally different to gear ,bearing noise,the fact a part has been replaced or new doesnt necessarily rule it out ,ive fitted alot of cheap exhausts that do that (vibrate under acceleration ) your not going to get any further till you try with one prop removed or you narrow down area ,or get someone to rev it while you check underneath using common sense,i prefer it when someone comes back and says tried that what next ,we can only give you ideas to try and using logic ,and known faults or narrow down from what it isnt ,