Front driver axle over heating

Was it overheating before you changed the fluid?
What is the temperature at wheel end?

First reason I think of with elevated temperature is bearing condition.
Maybe your sending unit or your gauge is going bad.

 

The temperature out by the wheels. Is it hot to the touch. Is it too hot to touch.

 

As was mentioned above, verify the temperature. I'd hit the diff housing and hubs in a few different spots with an IR temperature gun and see if you can find the source. If the readings match the gauge, you have a diff problem. If not, likely a wiring/sensor/gauge problem.

Was there any metal on the plugs? Chances are you're going to be replacing that diff if it is actually getting hot like that. Anything over 250°F means components are being damaged.

 

200 is not overheating. She is probably working hard maybe.

Nothing worried until the axles get past 250, that is where the damages begin relatively fast.

ESPECIALLY if both of your axles do not agree on each of their temps and do not agree with your transmission oil temp and do not more or less follow the engine oil temp.

 

Could try the thicker oil the 75-140 your probably have 75-90 that's the stand oil they use. The 75-140 can even be a little hard to find since most people just use the standard 75-90.

 

Check the vents on both axles, sometimes they get a bit clogged.

 

200 in the summertime is very normal we pull 100000 or better mine will run about 240 degrees

 

Replace the sensor on the axle.