Transferbox/gearbox noise

Started getting a noise underneath on my defender 1988 lt77 box
Mainly hear it at 40-60mph louder the faster I go the noise happens when I lift off slightly half ish throttle and when I dip the cutch.

I've had the same type of noise when the rear flange had come apart and I had that all fixed but its now come back?

Also I've had new front flange and seal and front prop a week or so ago

Any ideas thanks

check oil for contamination and intermediate gear for end float ,it can be removed by tightening outer nut carefully

jamesmartin said:

check oil for contamination and intermediate gear for end float ,it can be removed by tightening outer nut carefully

Click to expand...

Had an oil change on it recently On transfer box and it was full of gloopy horrible oil as found that breather was missing so it's not had a nice inside for a while could this cause it so replacement would be a good idea

without having the sump off and looking its hard to say unless there is other evidence