Change Driveline Fluids Early!

[JediMcMuffin]

I'm hoping some more informed folks than me can enlighten me on what kind of service intervals to shoot for here.

The owners manual indicates the following:

Oil /Filter Changes:
Normal (Mall Crawler/Daily Driver) - 7500-1000 miles
Severe (Used as intended, weekend off-roading) 5000-7500 miles
Extreme (you wheel the shit out of this thing) 3000-5000 miles

Operating in dusty areas:
- every 5000 miles

Normal Maintenance:
Every 20k - cabin air filter
Every 30K - engine air filter
Every 100k - spark plugs, inspect belts
Every 150k - automatic/manual transmission fluid, diffs + transfer case, replace belts
*Replace sparkplugs every 60k if you carry loads/tow occasionally

Off-Road Maintenance (meaning, you PRIMARILY off-road this thing):
- every 5000 miles - oil and filter
- every 30,000 miles - front diff, transfer case fluids (why not the rear?!)

***************************

How I drive and currently maintain my 2021 2.7L Automatic:
- It's my daily driver, occasionally 90 mile round trips to my company's HQ, kid/family duties too
- FPP tune is loaded, i like the extra power, hard accelerating onto the road but chill from there
- I schedule my full synthetic oil changes at the dealer shooting for 5000 miles, tends to happen around 5500
- off-roading is typically thurs/fri to sunday in anza borrego, big bear, or the eastern sierras quick but not crazy, maybe 4-5 times a year, monthly car camping though
- sitting at 33,000 miles

So given the theme of this thread which is "change them early" I'm also curious how early, and how often? Clearly I'm generating more wear then a mall crawler, but I think Ford's interval of 150,000 miles is absurdly long. I'm thinking every 50K given my usage.

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[userdude]

Yeah, it grinds

And it gets dirty!

So disassemble to change fluid is a good excuse to clean, or other way around!!!!
Love that skid, gives me piece of mind. It's 3/8 and 1/4 steel, should take hopefully more than I can throw at it!!!!

Is that the NVH diff skid? If so, what are your thoughts?

 

[Dorf2point0]

The theme of the thread is change all your driveline ( front differential, Transfer Case, and rear differential) fluids now.. Then you can baseline exactly where they are at the moment in time.. Front differential should have the magnetic plug ( does it have metal on it? ), then drain the transfer case, probably look like dirty engine oil ( hopefully there was a magnetic plug to look for metals..) Next, unbolt the rear differential and drain that fluid.. Look at the upper plug for metal, and try and wipe on the bottom of the rear different.. You are get all the metal grinds out of the case so that these particles and not being circulated.. I think this will tell you a story of how your components are wearing.. @CarbonSteel did an EXCELLENT job bringing this to light, and what you can do about it..

 

[Dorf2point0]

https://www.bronco6g.com/forum/threads/change-driveline-fluids-early.83929/post-2108566

 

[CarbonSteel]

Did the work today, a couple of notes.

The lower drain plug on the FP cover is 1/2 inch lower than that on the OE cover, see first two pics. Despite that, the FP cover takes exactly 2 quarts of oil till it starts overflowing the lower drain plug. I measured the old oil and it came out to slightly less than 2 quarts.

The lower edge of the FP cover is slightly above the diff housing (third image). I suspect that this is done intentionally so that if you drag the pumpkin there is less chance of snagging onto a rock and ripping the diff open.

Finally, I don't think it is necessary to buy additional magnetic plugs. You can just install the OE one in the lower position (it is magnetic) and keep the top one non magnetic.

The Ford Performance raised part likely adds some capacity, but at the same time, the tape appears to be below the centerline of the fill hole on OEM cover and above it on the FP cover so that is part of the difference.

The offset on the bottom of the FP cover is definitely to prevent snagging.

I would rather catch as much metal as possible which is why I added the magnetic plugs. Not my first rodeo with D44 Advantek's--they produce a lot of metal over a long period of time.

 

[CarbonSteel]

Clearly I'm generating more wear then a mall crawler, but I think Ford's interval of 150,000 miles is absurdly long. I'm thinking every 50K given my usage.

Although the use case can cause more metal to be generated, the caveat is these axles produce a lot of metal during break-in for a longer period of time regardless of use case. If you change the oil a few times before 25K you can likely leave it for 50K if you are just driving it.

 

[Tor148]

Is that the NVH diff skid? If so, what are your thoughts?

Yup
Next venture, love it. When I bought it it was the thickest one and strongest one out there and I don't think anyone has anything stronger since.

 

[MadMan4BamaNATL]

Guys, so, today was the day. The FP cover is on and full of AMSOIL 75W-90 (I hope!)

@CarbonSteel , I’ve said it before, but can’t say it enough; you’re doing God’s work here on Bronco6G and I am very thankful for your support, guidance, and the very kind gesture to stamp out clips to the proper size and mail to me. I won’t forget that and you will always have a friend here in me.

So, I‘m a tool. break line clips slide right off. I finally went back out, grabbed one of my trim tools and just pulled and off it went; didn’t have to unclip anything. Thanks to everyone who pointed this out more than once. I was afraid to pull too hard, but that now looks dumb. I can laugh about it now at least. Well, not really, but trying to get there.

What y’all didn’t tell me was how much of a pain it would be to line that damn thing up to screw in the bolts. I’m sure it would have been much easier and faster on a lift, but I just had the back raised a bit and sprawled over the ground on some cardboard.

Also grabbed the cheap fill tube suggested by CarbonSteel; it does do the job, just very slowly as it has a nasty backflow since it’s just awkward to get in there to let gravity take over. Love the open and shut action of it though although it would occasionally twist back to off.

Couldn’t remember, but set out to add 2 full quarts. Say that since the oil spilled back out a bit when adding the first quart which was strange, but after a break, more went in on restart; air maybe?

I used the fiber gasket that came with the cover and added some Permatex Black. Used my torque wrench in the pic to twist everything to the proper spec and put some thread lube on the plugs and torqued to spec there as well.

Not too much of a mess, but too much Permatex maybe even though I went light, but will watch for leaks for the next couple of weeks. Not wheeling for another few weeks, so that’ll be good.

Oil was dark and had shavings at 9848 miles, so was glad I changed the oil. No, 2 full quarts didn’t come out, but close.

Sorry for the long post, but thank you all again for the help and encouragement to man up and get this done.

Cheers to all of you guys!

 

[CarbonSteel]

Guys, so, today was the day. The FP cover is on and full of AMSOIL 75W-90 (I hope!)

@CarbonSteel , I’ve said it before, but can’t say it enough; you’re doing God’s work here on Bronco6G and I am very thankful for your support, guidance, and the very kind gesture to stamp out clips to the proper size and mail to me. I won’t forget that and you will always have a friend here in me.

So, I‘m a tool. break line clips slide right off. I finally went back out, grabbed one of my trim tools and just pulled and off it went; didn’t have to unclip anything. Thanks to everyone who pointed this out more than once. I was afraid to pull too hard, but that now looks dumb. I can laugh about it now at least. Well, not really, but trying to get there.

What y’all didn’t tell me was how much of a pain it would be to line that damn thing up to screw in the bolts. I’m sure it would have been much easier and faster on a lift, but I just had the back raised a bit and sprawled over the ground on some cardboard.

Also grabbed the cheap fill tube suggested by CarbonSteel; it does do the job, just very slowly as it has a nasty backflow since it’s just awkward to get in there to let gravity take over. Love the open and shut action of it though although it would occasionally twist back to off.

Couldn’t remember, but set out to add 2 full quarts. Say that since the oil spilled back out a bit when adding the first quart which was strange, but after a break, more went in on restart; air maybe?

I used the fiber gasket that came with the cover and added some Permatex Black. Used my torque wrench in the pic to twist everything to the proper spec and put some thread lube on the plugs and torqued to spec there as well.

Not too much of a mess, but too much Permatex maybe even though I went light, but will watch for leaks for the next couple of weeks. Not wheeling for another few weeks, so that’ll be good.

Oil was dark and had shavings at 9848 miles, so was glad I changed the oil. No, 2 full quarts didn’t come out, but close.

Sorry for the long post, but thank you all again for the help and encouragement to man up and get this done.

Cheers to all of you guys!

You are most welcome. It's good that you were diligent with the clips. They are made of "unobtanium".

Glad it all worked out!

 

[Dorf2point0]

You are most welcome. It's good that you were diligent with the clips. They are made of "unobtanium".

Glad it all worked out!

Im familiar with that Unobtanium… That’s what I experienced ordering 3 Ford Performance diff covers.. I received one initially and been waiting on Ford to investigate the missing two.. Then yesterday, the unobanium showed up at the door..

 

[The Bronc]

If you are using the OEM plastic brake line clips, the supplied studs should be fine.

I am looking to switch to stainless rubber lined clamps and to maintain the OEM orientation, I will need longer studs and double nuts to hold those clamps.

Be aware the plastic OEM clips are not available separately, they are only available with the left brake line (thanks Ford).

Do you have a link to what you purchased, stainless rubber lined clamps and studs or did you end up using the studs that came with the Ford Performance differential cover? Thanks

 

[CarbonSteel]

Do you have a link to what you purchased, stainless rubber lined clamps and studs or did you end up using the studs that came with the Ford Performance differential cover? Thanks

Here you go:

https://www.bronco6g.com/forum/threads/carbonsteels-journal.86135/post-2133960

 

[The Bronc]

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
This was a fantastic write-up and video series! Yo u answered all of the questions I had! Thank you!

 

[Felix808]

Probably a dumb question, but why two fill holes?

For adding a diff cooler. Usually only used in racing or track cars.

 

[tourproto]

So if you change the driveline fluids early, instead of at 150K miles like Ford says:

150,000 mi:
45. Change the automatic transmission fluid.
46. Change the manual transmission fluid.
47. Change the front axle fluid.
48. Change the rear axle fluid.
49. Change the transfer case fluid.
50. Replace the accessory drive belt(s). **

Do you wait until 150K for the next one? Is the reason for the early fluid change just to get rid of "break in" metal shavings?

Seems to be a very expensive maintenance item to do years before Ford recommends, especially for those of us that do not have a properly equipped garage to do this in. I haven't called my dealer yet about this, but my guess this is $100s of dollars, and I am not going to do it at an indy shop because I have the 8-year extended warranty, and not giving Ford any reason to deny my coverage for anything that goes wrong in that timeframe.

As I have mentioned in other threads, I keep my cars a LONG time (my 2nd vehicle, a 2004 BMW 330i is going strong at 20 years). I am totally on board with doing stuff that will demonstrably extend my vehicles life (like frequent oil changes, which I know make a difference when I drove my OG Integra 225K miles before needing a top-end rebuild, but the bottom-end needed nothing done because the crank looked like new, even under Magnaflux inspection).

Is there any independent documentation on the long-term benefits of doing early axle fluid and transfer case fluid changes?

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