Hot front diff- drivers side... WTF

As stated previously the bushing interface only sees relative motion if there's an imbalance in wheel speeds left to right. Just driving down the road there's not much rotation inside the bushing, it's rotating the same speed as the shaft it's supporting.

 

Nothing about the front diff makes it incapable or undersized for driving the truck. It's similar in gear size to rear gears that have been powering these trucks for decades. There's no special feature left out that would be required for it to be the primary drive axle. And it's the same hardware as used in AWD applications that see constant load for every mile the vehicle drives.

No, it wouldn't hurt to have more fluid capacity. No, it wouldn't hurt to have a slightly better CV support hardware. But that's not required.

I think most people just don't realize how hot differentials get. The front diff is more than capable of logging highway miles. OP, keep chugging along, you're fine. You probably smelled burning grease or oil flung from the normally static front driveshaft.

 

Replaced all the gear oil and took an 800ish mile trip this weekend- no issues. Well, besides my driveline vibe but I’m working on that.