Rear diff fluid
Senior Member
Joined: Apr 2012
Posts: 1,304
Likes: 133
From: Around
I have a 2012 5.0 ( 3.55's). This might sound dumb but want to make sure im not doing it wrong. I just did my rear diff fluid and when adding my new fluid i filled through the top plug till fluid began to trickle out fill hole. Screw the plug back in and was done. Did i overfill the diff or is that the proper procedure?? This is how i use to do it on my old f150
5 Year Member
Joined: Feb 2011
Posts: 2,582
Likes: 486
From: Maine
I've always had good luck with RedLine Synthetics.
Senior Member
Joined: Nov 2012
Posts: 264
Likes: 25
From: North of border
It's pretty important to check the color of the diff fluid once and a while.
If you off road water can contaminate the oil , milage IMO not the only thing to consider.
Full , 100 % synthetic from factory on tranny and rear diff. Extra oil changes still better than rebuilding.
I removed my diff covers when I changed the oil, inspected teeth for wear or chips.
Cover off means you can check for metal fragments and remove them.
Over fill not really an issue, truck will spit it out the vent hose if it has to.
If you off road water can contaminate the oil , milage IMO not the only thing to consider.
Full , 100 % synthetic from factory on tranny and rear diff. Extra oil changes still better than rebuilding.
I removed my diff covers when I changed the oil, inspected teeth for wear or chips.
Cover off means you can check for metal fragments and remove them.
Over fill not really an issue, truck will spit it out the vent hose if it has to.