Ford Performance rear diff cover installation, front diff and transfer case fluid swap how to

[Ape Factory]

Not seeing a maintenance or how to section on the forum so I'm posting it here.

I went and installed the Ford Performance rear differential cover and did a fluid swap on the front and transfer case as well. I used OEM fluids. I did everything with the car on the ground, no jacks.

Tools needed for the rear diff cover
I used 3/8 sockets for everything and have a small battery-powered impact gun which makes things go much more quickly
-10mm socket
-13mm socket, long
-13mm ratcheting box end wrench, straight
-15mm socket
-socket extensions as needed
-torque wrench
-flat blade screwdriver
-oil drain pan

Torque specs
-Differential bolts 29.5 ft.lbs
-drain and fill plugs 22 ft.lbs

Fluid
-Two quarts of Motorcraft 75w85 synthetic gear oil, p/n XY-75W85-QL

Parts
-Ford Performance rear differential cover for the Bronco Raptor, p/n M-4033-DR

The Braptor has three wiring loom brackets on the diff itself. I removed those along with the two on either side of the differential so I had more clearance to work. The two outer brackets on the axle are a bit of a pain to get off but a flat blade screwdriver helps. The clips/brackets on the studs pull off fairly easily.

I loosened the three studs first using the 13mm ratcheting box wrench. Once they're loose, you're able to use a 13mm long socket and an extension with the impact gun to get them off. The 10mm come off easily and there's really no reason to work them loose in a cross pattern. Once two of the bottom 10mm bolts are removed, fluid will leak out so make sure the drain pan is in place.

The fluid wasn't too dirty and still had an amber hue to it although there were lots of ultra fine particles which as we all know are a result of break-in.

Photo of the stamp on the diff just for sh*ts and giggles.

With the fluid drained, clean the mating surface on the differential case AND the cover. Carb cleaner works just fine as does denatured alcohol on the new cover. I'm using the included fiber gasket as I don't intend to take the cover off anytime soon. I'm sure Fel-Pro or someone else will have a replacement gasket for those who need it. I forgot to shoot a photo of the gasket itself to see who the manufacturer is.

Follow the included instructions for the tightening sequence and torque specifications. Make sure to tighten the drain plug to specification before filling!

There are two fill ports. Since the diff has had fluid in it before, you'll use the bottom port. There's enough room to simply use the bottle to squeeze the fluid in. For the first fluid container, there was a bit left at the bottom using this method and I simply dumped the remaining amount into the second bottle. Once done with the second bottle, and given there's some left over at the bottom, I went to the third bottle. A bit of fluid will drip out once you've reached the proper level.

Install the drain fill plug, torque to spec. Re-attach all the wiring loom clips and you're good to go! It took me about 40 minutes, taking it slow, to install the cover. I do believe the FP cover requires more fluid vs. the OEM cover. I purchased three quarts and it was enough for the rear and front differential. Even though I moved on to the third bottle, there was enough for the front diff once the rear was filled.

 

[Ape Factory]

With the rear differential done, I moved on to the front differential. The front differential and the transfer case are both protected by skid plates and require removal. Both are held on by four 15mm bolts each. Remove those to expose the front differential and transfer case. The transfer case is visible without removing the skid plates but the fluid would drain onto the skid plate so removal is necessary.

The front differential is best accessed from the front or passenger's side. It's oriented towards the driver's side but the drain and fill plugs point towards the passenger's side.

If you're not using some sort of squeeze container, you WILL need a fluid transfer pump. My pump didn't work very well so I rigged up something using the pump's hose and used the squeeze/gravity method. It worked but wasn't ideal. The pump I had didn't work with the smaller mouth on the gear oil containers so plan ahead and accordingly.

Tools and supplies needed:
-3/8 wratchet
-15mm socket
-fluid pump
-drain pan
-thread sealant like Permatex

Fluid needed:
-1 qt. of Motorcraft 75w85 synthetic gear oil, p/n XY-75W85-QL

The fill plug is at the 3 o'clock position and the drain is at the 6 o'clock position.

Start by removing the fill plug FIRST. If you cannot get the fill plug off, do not proceed. If you remove the drain first, and the fill plug won't budge, it's a flat bed to the dealer. It's unlikely but better safe than sorry.

With the fill plug removed, position the drain pan and remove the drain plug. I had surprisingly little fluid come out and I think my front diff was under-filled from the factory.

The plug is magnetic and it had lots of fine particles and the fluid didn't look too bad. I have about 15K miles on the clock currently.

Clean the plugs, apply thread sealant. Install the drain plug and torque it to 22 ft.lbs.

Fill with fresh fluid using your fluid pump. I used a hair less than a full quart. It'll dribble out when it's reached the proper level. Install the fill plug and tighten to 22ft.lbs.

Reinstall the skid plate and the four 15mm bolts. I just snugged them down tight. That's it! Total time with a good fluid pump would likely be about 20 minutes.

 

[Ape Factory]

Onto the transfer case. A fluid pump is necessary. If you have one that can adapt to the mouth of both bottle types, make sure to clean it thoroughly. I prefer and recommend just using a new one a they're cheap and easy to get off of Amazon.

Tools needed
-3/8 wratchet
-15mm socket
-fluid pump
-drain pan

Parts and supplies needed
-Motorcraft Mercon LV, p/n XT-10-QLVC

Start by removing the four 15mm bolts holding the skid plate on to expose the entire transfer case. The fill port can be seen upper right with the drain, lower left. Remove the fill plug FIRST.

Position the drain pan. Note, the fluid will shoot out and towards the back of the Braptor so don't position the pan directly under. If it's fairly long, position it longitudinally to the predicted flow and be prepared to move it back as the fluid drains. There's quite a bit of fluid and it'll slow to a dribble. The fluid looked ok, just a bit dirty.

Wipe off the area around the drain. Clean the drain plug and use thread sealant. Reinstall the drain plug. The Transfer case is aluminum so don't over tighten the plug.

Using your fluid transfer pump, fill the transfer case with approximately two quarts of fluid. It'll start to dribble out the fill plug when you've reached the proper level.

There will be about 200ml left so two quarts is enough.

Clean any fluid on the outside of the transfer case, clean the fill plug and dab your thread sealant on it. Install the fill plug and torque to specification. Reinstall the skid plate with the four 15mm bolts. That's it! You're done. The transfer case was the easiest, IMO, and took about 20 minutes.

 

[Bschurr]

Nice write up @Ape Factory and thanks for sharing - this is certainly useful & now bookmarked for future reference.

 

[Sherpa11]

great write up thanks!

 

[Ape Factory]

We really need a DIY/Maintenance section. As these cars come out of warranty, I suspect a lot more people will begin wrenching on them.

 

[Dragoon]

We really need a DIY/Maintenance section. As these cars come out of warranty, I suspect a lot more people will begin wrenching on them.

Agreed! I just added a new Maintenance forum and moved this thread to it.

 

[Ape Factory]

Sweet! Thanks Dragoon! I'll try to add more content as I do more stuff. Did a lot of DIY maintenance stuff for a particular German car brand and have a YouTube channel but I don't have a ton of time these days to shoot/edit video. I think an oil change will be next and I'll do a very to the point, concise video on that.