Change Driveline Fluids Early!

[CarbonSteel]

This last weekend I changed the front diff, rear diff and transfer case fluids. I tried several different ways to put new fluid in and I've come to the conclusion its a mess no matter what.

One thing I wish I would have realized prior to removing the rear diff cover is that the top of the stock diff plate plus the thickness of the gasket holds a lot of dirt and dust. When I removed the cover and all kinds of crud fell down on the gears. I was not a happy camper. Tried to wipe it out the best I could but I know I didn't get it all. Just clean the top as good as you can prior to opening the cover!

I installed the FP Diff cover plus the DV8 diff skid which I had to modify to fit over the new cover. I think it came out pretty good and I have the benefit of the new cover plus protection.

Grab one of these for next time and it will be an easy and clean filling process. I cut about 6" off the tube and it made the job a snap.

https://www.amazon.com/Hopkins-10106B-FloTool-Filler-Refill/dp/B000EH4UXM

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[Deano Bronc]

Yep, I did get one per your recommendation although I didn't cut down the tube. It was just tough to get the bag high enough especially on the front diff. The rear is not nearly as tough especially if you have the axle assembly at full droop. The transfer case was somewhere in the middle.

 

[CarbonSteel]

Yep, I did get one per your recommendation although I didn't cut down the tube. It was just tough to get the back high enough especially on the front diff. The rear is not nearly as tough especially if you have the axle assembly at full droop. The transfer case was somewhere in the middle.

Yeah, I had to play with the length of the tube a bit to find the sweet spot. I used regular quart bottles, and it was more difficult to squeeze them versus orientation.

 

[Bearcat1]

This last weekend I changed the front diff, rear diff and transfer case fluids. I tried several different ways to put new fluid in and I've come to the conclusion its a mess no matter what.

One thing I wish I would have realized prior to removing the rear diff cover is that the top of the stock diff plate plus the thickness of the gasket holds a lot of dirt and dust. When I removed the cover and all kinds of crud fell down on the gears. I was not a happy camper. Tried to wipe it out the best I could but I know I didn't get it all. Just clean the top as good as you can prior to opening the cover!

I installed the FP Diff cover plus the DV8 diff skid which I had to modify to fit over the new cover. I think it came out pretty good and I have the benefit of the new cover plus protection.

I have the DV8 Diff skid currently installed, purchased the performance cover but have not had time to install yet. How much modifying on the skid did you have to do and did you create a hole on the bottom to allow for draining without removing the skid (or maybe the drain hole sticks out far enough past skid for access)?

 

[Deano Bronc]

I have the DV8 Diff skid currently installed, purchased the performance cover but have not had time to install yet. How much modifying on the skid did you have to do and did you create a hole on the bottom to allow for draining without removing the skid (or maybe the drain hole sticks out far enough past skid for access)?

There is enough room to access the drain without cutting into the plate.

Here are all the areas that needed modification. The upper side holes should have been made a little bigger but once I got it up there, I wasn't going to bring it back down. All the ribs of the diff cover needed clearance on the skid plate. The area I have circled could have been much smaller but it turned out fine.

I was initially concerned about removing too much material and weakening it but as you know, it is a very strong and robust weldment. I have no concerns now.

 

[Bearcat1]

There is enough room to access the drain without cutting into the plate.

Here are all the areas that needed modification. The upper side holes should have been made a little bigger but once I got it up there, I wasn't going to bring it back down. All the ribs of the diff cover needed clearance on the skid plate. The area I have circled could have been much smaller but it turned out fine.

I was initially concerned about removing too much material and weakening it but as you know, it is a very strong and robust weldment. I have no concerns now.

Thx, very helpful. I will uninstall the skid plate and make the mods before I install the performance cover.

 

[Lak34ers]

Gang,

I just completed changing the fluid in the front axle, transfer case, and rear axle and added a Ford Performance cover on the rear axle at the same time. I changed all 3 at 2500 miles, the Bronco now has 5000 miles on it, so another 2500 mile run on all three.

I did not find anything unexpected and overall it was a smooth process--that anyone can do. I am not a professional videographer and so the rear axle is a few videos, but by the time I made it to the transfer case, I had figured it out. Apologies for the multiple videos, bad angles, and having to listen to my voice.

I am happy to answer any questions.

This funnel is a lifesaver - https://www.amazon.com/Hopkins-10106B-FloTool-Filler-Refill/dp/B000EH4UXM

Front Axle Video -



- Amsoil 75W-110 fluid (about 1.2 QTs) - https://www.amsoil.com/p/severe-gear-75w-110-svt/?code=SVTQT-EA
- Permatex 59214 High Temperature Thread Sealant (https://www.amazon.com/Permatex-59214-Temperature-Thread-Sealant/dp/B0002UEOP0)
- I chose 75W-110 because it is the upper viscosity that 75W-90 used to be before the SAE J306 table update in 2005 AND because the capacity is so small. I also had it in my stash--I will switch to 75W-140 when it runs out.

Transfer Case Video -



- Motorcraft Mercon LV fluid (about 1.8QTs) - https://www.amazon.com/Ford-XT-10-QLVC-Oil-Automatic/dp/B07ZTRVLX9
- Permatex 59214 High Temperature Thread Sealant (https://www.amazon.com/Permatex-59214-Temperature-Thread-Sealant/dp/B0002UEOP0)
- I chose Motorcraft Mercon LV versus Amsoil, Red Line, Royal Purple, etc. because there is no combustion by products, the temperatures are nominal, and Motorcraft is cost effective. From my viewpoint, changing standard Motorcraft Mercon LV more often is better than running a premium synthetic longer.


Rear Axle:

- Amsoil 75W-140 fluid (about 2 QTs) - https://www.amsoil.com/p/severe-gear-75w-140-svo/?code=SVOQT-EA
- PTFE Megatape (Gray) - https://www.amazon.com/HERC-15100-1-2X1000-MEGATAPE/dp/B00LO49TV2
- I chose 75W-140 because Dana recommends it for the M220 axle (they also recommend it for the M210 front axle). Any 75W-140 off the shelf (Castrol, Mobil, or Valvoline, etc.) will also work if you do not want to order Amsoil.
- The bolt thread depth in the axle housing is 23mm. If using the OEM rubber and steel gasket with the Ford Performance cover, then you need M8 bolts that are 25mm long. The supplied bolts with the cover are 20mm and they will be too short for the OEM gasket.

Video 1 - Tools and Parts -

Video 2 - General Discussion About Cover/Brake Line Clips & Prying on Cover -

Video 3 - Initial Drain -

Video 4 - Inspection and Cavity Discussion -

Scott towel showing metal from cavity:

Video 5 - Cover Installed and New Brake Clamps -

Video 6 - OEM Brake Clip Construction -

Rear Cover Hardware (NEW longer flange bolts are needed if using OEM gasket because it it thicker. They are not needed if using the supplied gasket with the Ford cover--use the supplied bolts that come with the cover):

Flange Bolts: M8x1.25x25mm long - https://belmetric.com/m8-coarse-din-6921-flange-bolt-class-10-9-steel/?sku=BFD8X25YLW

Brake Line Studs: M8x1.25x75mm long - https://belmetric.com/m8-double-end-stud-class-10-9-hardened-steel/?sku=SH8X75DBLK

Stud Washers: https://belmetric.com/hv-350-steel-thick-extreme-strength-din-6340-fender-washer/?sku=WFEHV8X23YLW

Stud Flange Nuts (against cover and one side of brake line clamp): https://belmetric.com/class-10-steel-tall-collar-flange-nut-din-6331/?sku=NFFH8TALLYLW

Stud Outside Nuts: https://belmetric.com/din-6923-coarse-full-wrench-stainless-smooth-flange-nut/?sku=NFF8X13SS

Magnetic Drain Plugs:

Low-Pressure 316 Stainless Steel Plug with Hex Drive, Hollow with Magnet, 1/2 Pipe Size https://www.mcmaster.com/1457N14

Quick question why not just use the new diff gasket? Is it inferior to oem? Is there a sealant that is needs to be purchased when installing the new performance diff gasket?

 

[CarbonSteel]

Quick question why not just use the new diff gasket? Is it inferior to oem? Is there a sealant that is needs to be purchased when installing the new performance diff gasket?

It is inferior from my point of view. It requires sealer that is messy to clean up.

The OEM gasket can be reused many times before replacement is needed with no cleanup.

Also, I could find no replacement for the gasket included with the cover which means back to the OEM at some point anyway.

 

[GroovyGeek]

I considered that also. But @CarbonSteel has a Wildtrak just like me, so we both have the advanced transfer case. Yet his had a magnet and mine did not

Yet another example of the masterful supply chain management that Ford has deployed over the past 4 years. I guess we now need to add magnetic drain plugs to the list of commodity constraints, right after other ultra unique and difficult to provide items such as a $100 hitch, subwoofer and amp, etc. Someone should nominate their head of supply chain management for an incompetency award.

 

[SWLABRONCO]

I changed the oil in the front/rear differential and replaced the fluid in the transfer case. Went with all Amsoil products. The quart easy bags are the way to go. No mess at all. Used 75w-110 in front and back and amsoil signature series ATF in the transfer case. My bronco is a 23 outerbanks sasquatch and I noticed that I didn't have a magnet on the drain plug for the transfer case. I installed the Ford Performance differential cover on the rear, so I just used the fill plug in the old differential cover and put it in the transfer case drain hole. Thanks to carbonsteel for all the great info. This has turned out to be one of the best Maintenance related threads on B6G.

 

[RedSoloCup]

Looks good

It is inferior from my point of view. It requires sealer that is messy to clean up.

The OEM gasket can be reused many times before replacement is needed with no cleanup.

Also, I could find no replacement for the gasket included with the cover which means back to the OEM at some point anyway.

I wonder if Mag Hytec has a gasket? I had to buy one from them as Ford doesn’t have one for the F150 rear diff housing i had.

 

[CarbonSteel]

Looks good


I wonder if Mag Hytec has a gasket? I had to buy one from them as Ford doesn’t have one for the F150 rear diff housing i had.

Ford doesn't have an OEM gasket for a F-150?

 

[RedSoloCup]

Ford doesn't have an OEM gasket for a F-150?

they use gasket maker on them. I think it’s the 8.8 rear end housing size. I think the bigger one has an actual gasket from what i remember. I changed my fluid and didn’t wanna deal with gasket maker. Had to look aftermarket. FYI this was a 2021 F150 2.7 4x4.

 

[CarbonSteel]

they use gasket maker on them. I think it’s the 8.8 rear end housing size. I think the bigger one has an actual gasket from what i remember. I changed my fluid and didn’t wanna deal with gasket maker. Had to look aftermarket. FYI this was a 2021 F150 2.7 4x4.

Ah, gotcha. Unless they changed the 8.8, there should be a pretty strong aftermarket for them.

The Dana 44 under the Bronco is the same as the Wrangler so there should be some options.

 

[RedSoloCup]

Yea for sure.

The gasket was a very nice reusable one for like $20-25 i think. Probably one from them for this housing

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