Front Diff Fill Plug

DaveH71 · November 3, 2011

That bolt your looking at on the front end, is in fact the fill plug. The drain plug is right below it. On the rear end there is no drain plug, you have to remove the cover to get the fluid out. Just loosen the top bolts a little so the cover can hang on them and remove the lower bolts. Then just pry the cover off with you fingers or a flat blade screwdriver. Be careful not to gouge the gasket mating surface on the diff.

RockySierra · November 3, 2011

What kind of fluid do you like to use for front and rear? The rear on mine has the G-80.

DaveH71 · November 4, 2011

My rear is a g80 to, i like redline 75w90. I use their 75w90 that doesnt have limited slip additive for my front and rear.

Ajsjdjdjfjdtgg · November 4, 2011

im the guy who started the thread, and yup thats the fill plug! its a pretty large opening.

as far as the rear goes, i did that at the same time. you have to remove the cover (cause you have the 5.3l engine/axle). as far as that fill plug goes, any 3/8 ratchet wrench will work to get that off.

good luck

WilliamBos · May 9, 2015

Is the big rusty bolt with what looks like a washer the fill plug?

DaveH71 · May 10, 2015

That's it, you got it.

Cowpie · May 17, 2015

Sure was a nice surprise to find an actual drain plug on my 2015 2500 6.0L rear diff. It is recessed into the botton of the diff, between a couple of ridges. If I hadn't have been feeling around under there, I would never have found it. Makes me kick myself for not looking closer under the rear diff on my 2013 1500 to see if there might have been one there.

But the front diff fill plug on the 1500 is larger than one on my semi truck. Sure didn't have any trouble filling back up when I did mine.