whistling noise after replacing front differential??

[Rahmein]

Ive posted before about how i put my explorer into 4WD without any gear oil in the front diff which burnt up everything inside and i had to get a new front diff (i picked up a used one from a wrecking yard). well my mechanic installed the new diff and now i hear a whistling noise coming from somewhere NEAR the front diff. im pretty sure its not coming from the diff itself but somewhere around it. this whistling noise gets louder when i accelerate. im thinking there might have been other damage done other than the front differential. i tried to follow the sound as much as possible and it is sounds like it is coming from these parts under the truck. anybody know what parts these are and if they can be related to my situation??

 

[Rahmein]

Anybody?

 

[IZwack]

Thats the transmission -- and yes it can whine.

 

[Turdle]

That is a totlly unrelated area-
first picture is the bell housing , second is the transmission pan.

Is it a whistle (like with air ) or more of a whine (like gears meshing)?

 

[Rahmein]

It's more of a whine. Also, when replacing the front diff, does the seal need to be replaced around the cover for the gears??