Front Differential Whine

[Havok]

Was driving the truck to the beach the other day and I started getting a really loud whine once it was all warmed up. Was only occurring when it was moving and in gear and sounds to be coming from the engine cover area. Since it was only doing it when in gear and moving and not in neutral and under load I am assuming its my front diff. Could be I missing something bigger here? Is the front diff a common breakage item? Thoughts on repair or upgrading to something stronger etc.

Would love some advice and/or input

 

[Mainsail]

C-141B crewmember joke:
What the difference between a C-5 crew and the C-5 engines?
The engines stop whining when they block in.

Anyway, the experts will be along shortly so I'll just ask; when was the last time you inspected the hubs? I would park it until you have.

 

[Havok]

Hubs are good. Thanks for the humor

Sent from my SM-S908U using Tapatalk

 

[Havok]

What are people using for gear oil? I assume 75-90 gear oil but any preferred brands? I'm usually a Mobil 1 fan but Ive heard mixed results with their gear oil.