Do I need to change differental fluid?

[Matt98svt]

Hi all,
My 2007 4.0 V6 Eddie Bauer Explorer 2wd currently has 160k miles. At 150k I changed the tranny fluid per the manual and it made a huge difference in how smoothly it shifts and even seemed to boost my mpg a little. In fact, I wish I had done the transmission fluid much sooner than what the manual called for. All this has had me thinking about changing the rear diff fluid so I have been reading post here on the forum about it and seems to be mixed information. So I guess my question is, do I need to change the rear diff fluid in my explorer or not? Will it make any difference? It seems like it would get old after all these years and the owners manual would call for it. If I do change it out what synthetic fluid should I use and how much..Im familiar with the process of doing it just see different weight fluids recommended in other post here. Thanks in advance.

 

[michael loibl]

Quite certain the rear calls for 75/140 synthetic, but it’s in the owners manual. I could check mine later if u don’t have one

 

[swshawaii]

Maintenance and Specifications (Page 356)
http://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/07expog2e.pdf

 

[Matt98svt]

Thank you, I did find it in a chart in the pdf manual linked. I must have passed over it when flipping through mine. Going to go ahead and change it this weekend. I also read about friction modifer additives. Do I need to add any of that or just the fluid. Thanks

 

[swshawaii]

Use friction modifier if you have a limited slip differential. Regardless if the 75W-140 gear lube has FM mixed in, use the OE Motorcraft XL-3 for best results. One four ounce bottle from the dealer "should" suffice. If unsure, check the axle code printed on the bottom of the drivers door sticker, or the metal tag attached to the rear 8.8 cover.

Axle Tag Codes for Ford Explorer, Ford Ranger and Ford Bronco II Axle Identification

 

[swshawaii]

Also Matt, be prepared. After 160k, your gear lube will likely be the smelliest and messiest fluid change ever. Highly recommend wearing gloves, and having lots of cleanup rags ready when you break the seal. Refill on level ground until
the gear lube comes out of the fill plug on the axle. Probably the last time you will ever do this to your vehicle. Good luck.

 

[michael loibl]

As far as I know, no 4th gens came with limited slip rear

 

[hwydave]

Swshawaii is right about the old oil, it is smelly and will stick to your cloth for a long time.

Mobile 1 also sell rear differ oil but I used Motorcraft oil. Pumping those heavy oil into do take some time. I changed my at 98k miles but I will probably do it in another 60k miles since I haul heavy stuff in my truck and we live on the hill.

 

[swshawaii]

^ Good point. Store gear lube at room temperature before using, or your hands will work harder than necessary. Also, LOOSEN the fill plug BEFORE draining. Some nightmare threads on EF where the plug was found seized after draining.