Rear Differential Fluid Change

[Hoos95]

I have a 2007 Expedition EL w/ 360K miles. I am the second owner and am not aware of the rear differential fluid ever being replaced. Axle code 16 meaning it is an open differential not needing the 4oz friction modifier additive, according to FordTechMakuloco on YouTube, but should I add anyway?

Before I start this project, I wanted to confirm the fill plug and the drain plug on the differential. I took pictures of what I assumed to be each, the first one below being the fill plug and the second one being the drain plug. Do I have that correct?

According to the manual, the new fluid will be Motorcraft SAE 75W-140.

 

[07navi]

Plugs are right and most don't even have the bottom one. Why would you want to add modifier if it doesn't take it?

 

[Hoos95]

Plugs are right and most don't even have the bottom one. Why would you want to add modifier if it doesn't take it?

Good and thank you! I was pleasantly surprised when I noticed there was a drain plug and didn't have to take the cover off.

As for the modifier, FordTechMakuloco says: "You can add friction modifier to any axle and no harm will be done... it is better to be safe than sorry and just add one entire bottle with your new axle." I just wanted gauge opinions.

 

[Shantheman73]

I have a 2007 Expedition EL w/ 360K miles. I am the second owner and am not aware of the rear differential fluid ever being replaced. Axle code 16 meaning it is an open differential not needing the 4oz friction modifier additive, according to FordTechMakuloco on YouTube, but should I add anyway?

Before I start this project, I wanted to confirm the fill plug and the drain plug on the differential. I took pictures of what I assumed to be each, the first one below being the fill plug and the second one being the drain plug. Do I have that correct?

According to the manual, the new fluid will be Motorcraft SAE 75W-140.

View attachment 35040

View attachment 35041

Is that 360k miles or kilometers?!


2007 Ford Expedition Limited
Sent from my iPhone using Tapatalk

 

[07navi]

Good and thank you! I was pleasantly surprised when I noticed there was a drain plug and didn't have to take the cover off.

As for the modifier, FordTechMakuloco says: "You can add friction modifier to any axle and no harm will be done... it is better to be safe than sorry and just add one entire bottle with your new axle." I just wanted gauge opinions.

That's only needed for the clutches if the limited slip rear end. Makuloco said you could but maybe you took it wrong. Open diffs don't use it.

 

[Hoos95]

Is that 360k miles or kilometers?!


2007 Ford Expedition Limited
Sent from my iPhone using Tapatalk

I'm at a little more than 367K miles, not kilometers.

 

[Hoos95]

That's only needed for the clutches if the limited slip rear end. Makuloco said you could but maybe you took it wrong. Open diffs don't use it.

Understood and I won't add it.

 

[Shantheman73]

I'm at a little more than 367K miles, not kilometers.

Outstanding! Love hearing that!


2007 Ford Expedition Limited
Sent from my iPhone using Tapatalk

 

[07navi]

That's SYNTHETIC 75-140 and it is interesting that the rear end lasted that long with no change but it did have the synthetic in it. Ford recommends that you change it every 100k miles (and use synthetic).

 

[07navi]

I'm at a little more than 367K miles, not kilometers.

Did you buy it new? Do you know if the chain tensioners or variable cam timers were ever replaced ?