Today I noticed my diff looks like its leaking. It's not dripping but I looks like oil has gotten out and dirt got all over it, nothing drips on the floor though. I see this in other trucks sometimes but is this bad?

 

That's called a seep, and no a seep is nothing to worry about. If you start to see fluid on the ground or drops forming on the bottom of the diff, then worry and fix it, then stop worrying.

 

Bad if you go muddin and submerge the diff, not so horrible if it's weeping and not actually leaking... Meaning if you gotta top it off, and wait a year to top it off again no big deal..

Myself, I would take care of it... Pretty simple process to clean and reseal and it's always good to change fluids!

 

I had the fluids checked about 25k miles ago and the said it was fine but that's when I bought the truck, they said it was fine.
I'll check it tomorrow. All I do is pull the plug and make sure it's almost to the hole in the diff right?

 

Yeah, like 1/2" below the hole is fine...

Check and make sure your axle vent is clear while you're under there...

 

What is the axle vent? And where is it located?

 

It's the rubber tube that comes up off the distribution block for the brake lines in the rear and goes up under one of the bed supports...

The bolt that holds the brake block down has a through hole right into the axle tube...

The vent should be clear of any obstructions

 

Oh ok I'll check it out
Thanks for the help

 

No problem!

 

On mine the vent tube is split at the axel I should replace that right