Change Driveline Fluids Early!

[CarbonSteel]

If you always get metal paste, I would say your not changing your fluid often enough. Many do no change gear dope the entire life of an axle, not saying any time interval would not work.

Admittedly if I was paying to have maintenance work done I would not change so often, or if I did not have a convenient place to do the work. I get enjoyment from maintenance activities, almost as much as actual machine use. The way I look at it I invest all my cost 'savings' into better materials. I keep my machines long term, if one has no plans to keep a car just do the bare minium recommended (this is why I never buy used).

I disagree to a large extent, but it can depend on load, operating conditions, oil type, and viscosity. You have two gears moving at 90° to each other under incredible shearing forces that will cause wear metals to be generated. Sadly, Dana 44 Advantek axles produce more for long periods of time versus other axle types. Ergo, you will always see paste on the magnets if the run is at least a few thousand miles.

In my 2019 Wrangler that has the same axle as the Bronco, I regeared from 4.10 to 4.88 to 5.13. On both sets, I had them REM Isotropic polished which produces a near chrome like surface finish and completely eliminates the need for heat cycles during break-in. It also substantially reduces the wear metals generated—but there was still wear metal collected on the magnets. It is just something that cannot be avoided, but can be reduced by the polishing.

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[Callelk]

You can follow my UOAs here

Interesting, do find your T-Case numbers to be typical at 9.5K?

 

[Ziemann]

'23 Big Bend 2-door 2.3L Manual Transmission - spends annually 3+ months in 4WD and tows 3,000-5000 miles/year. Fluid Change Complete.

This is my second fluid change on the MT88 (done again because I have "the noise")- but the first on the diffs and transfer case. My first change on the MT88 was at 1800 miles at break in, and this one was completed at 24,000 miles.

Front Diff: Existing fluid was much darker than expected with minimal metal sheen in the oil pan. Expected goo on the drain plug magnet. Replacement Fluid: Amsoil Severe Gear 75W/90. The Amsoil was on sale and available at my local NAPA. Win.

Rear Diff: As expected- normal goo on the drain plug and dark colored fluid w/ a metal sheen in the oil pan. It needed to be changed. I wiped out the diff with clean cloths and was surprised to see how much goo was settled in the bottom of the diff. Replacement Fluid: Amsoil Severe Gear 75W/90. @CarbonSteel recommends a higher viscosity (which is good advice) based on the belief that the higher viscosity will handle heat better and resist breakdown. I don't have a problem with that logic. Amsoil is a very well proven synthetic, and should also handle the heat very well and resist breaking down even at 75W/90 (which is now Ford's current recommendation). I don't see a problem either way. As @CarbonSteel has stated, the most important factor is how frequent you change the fluid, and not the viscosity in that rear diff.

Transmission: I have had the grinding noise in my MT88 manual since around 800 miles on the vehicle. My MT88 has always performed well and shifts like a dream in spite of "the noise". At 1800 miles at break in, I changed the OEM fluid out for BG Synchro Shift II. That was a great fluid, and it performed very well even during the winter. The fluid was in great shape and probably didn't need to be changed. This change, I used Redline MTLV. I found it IN STOCK at a local O'Reilly Auto Parts! This fluid also performs extremely well, is buttery smooth, and has shifted very well at temps at around 5 degrees F. IMPORTANT: I don't know if it is a placebo effect- but "the noise" seems to improved. Placebo effect?

Transfer Case: The existing fluid looked good with just a slight brown color and no obvious contamination. It probably didn't need to be changed. Replacement Fluid: Pennzoil Platinum LV Synthetic- in stock and on sale at a local Menards for $4.89/quart! This meets Ford spec and is a very well reviewed fluid.

Draining and filling were easy, and just about anyone with minor mechanical ability should be able to complete a drain/fill. Frankly, it is so easy that really should be no excuse to neglect this important maintenance. Ford is simply WRONG on their fluid change intervals, and if you do the changes yourself, it can be done at a reasonable price using locally sourced fluids that meet OEM specs.

 

[CarbonSteel]

Interesting, do find your T-Case numbers to be typical at 9.5K?

We would need some trending data from a number of transfer cases to establish what would be considered "normal", but in lieu of that, I did not see anything out of the ordinary.

The most important thing that you want to see is the miles per PPM of iron/aluminum/copper increasing which means that less wear metals are being generated per mile which indicates the unit is breaking in and wearing normally.

As a transfer case or axle breaks in (or any non-filtered & non-pressurized equipment), the wear metals should reduce until they hit a steady state which can have some variations, but by and large land within a range.

You can see on my Jeep Wrangler transfer case how the length of run increased but so did the miles per PPM of iron (as an example). This is the trend that you want to see:

 

[Sparkherd]

Change 7MT fluid yesterday. 11,707 miles
Old fluid did not look bad.
A few metal flakes visible in the drain pan, but I've seen worse.
BG Synchro II is some slimy sheeit!!!
Almost 2.8 quarts before the fluid started trinkling out the fill hole.
Tranny is guieter at start up, and much smoother on the road.
I am slightly amazed at how much difference this made.
Oh yeah...I could only get the fill plug back in when the tranny was in Granny Gear; the shifter arm interfered with the fill plug in neutral.
This may not be a problem for those of you with helpers, or the young, but it's PIA to get up off of the floor, and waggle the shifter around, until you can get the fill plug to thread.
Your mileage will probably vary...

 

[vicorjh]

Another rear differential specimen (4K miles):

Front differential. Waste oil in similar condition as to the rear with metal paste on the drain plug:

 

[jsoa]

this thread should be pinned imo. @CarbonSteel thanks for all the info and effort you put into this. I admit I ran away from this thread multiple times as I have never done anything like to any of my vehicles, but after slowly reading through it, I feel pretty confident in doing these fluid changes now.

Ordered the FP cover but plan to use the OEM cover on the first change then after the second change I'll put the FP cover as I get more comfortable with changing these.

 

[B_Dominant]

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):


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

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

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

4 Each - 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

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

Magnetic Drain Plugs:

3 Each (if replacing all to be the same) - Low-Pressure 316 Stainless Steel Plug with Hex Drive, Hollow with Magnet, 1/2 Pipe Size https://www.mcmaster.com/1457N14

@CarbonSteel Do you know where I can get these bolts but in stainless?? I live in the rust belt.

 

[CarbonSteel]

@CarbonSteel Do you know where I can get these bolts but in stainless?? I live in the rust belt.

Yes sir - here they are in black stainless:

https://belmetric.com/m8x1-25-flange-bolt-black-stainless-coarse-din-6921/?sku=BF8X25BLKSS

 

[vicorjh]

At 4K, the transfer case fluid does appear to have some very fine metal contamination. Adding a magnetic drain plug.

Anyone have concerns with corrosion being that the TC housing is aluminum. The original TC plugs have what appears to be a heavier zinc dip relative to the diff plugs.

 

[CarbonSteel]

At 4K, the transfer case fluid does appear to have some very fine metal contamination. Adding a magnetic drain plug.

Anyone have concerns with corrosion being that the TC housing is aluminum. The original TC plugs have what appears to be a heavier zinc dip relative to the diff plugs.

Stainless and aluminum typically do not play very well together, but if you are using teflon paste or tape, that should provide enough boundary/lubrication to prevent/limit corrosion.

 

[vicorjh]

Stainless and aluminum typically do not play very well together, but if you are using teflon paste or tape, that should provide enough boundary/lubrication to prevent/limit corrosion.

I'll try a non-stainless plated drain plug that was pulled off the diff on the TC whereas stainless plugs on the diffs. Paste on all plugs. Will keep an eye on them regardless.

 

[CarbonSteel]

I'll try a non-stainless plated drain plug that was pulled off the diff on the TC whereas stainless plugs on the diffs. Paste on all plugs. Will keep an eye on them regardless.

Almost positive the threads are the same between them (1/2" NPT) so that is a good plan. I am doing the same when I change the transfer case fluid next time.

 

[vicorjh]

Almost positive the threads are the same between them

Yup, they are the same.

*seems unusual for Ford. Kudos.

 

[Tor148]

Did an event last weekend with the Braptor. Ran hard so wanted to change the fluids again.
Had already changed the Front Diff, Rear Diff and transfer case around Christmas with about 18k on the clock. All Amsoil. 75W110 up front, 75W140 in the rear.
Have 28k on the clock now.
Did the the front diff, this is the magnet, metal paste on it.

Drained into a container to see how it looked. You can see metal grains in there

Fluid pouring into drain container you can see it's pretty dark!

This is the Transfer Case.
Can't believe how clean it looks! That's the fill plug in the bottom of the container. Fell in there

This is the rear diff.

More metal paste

Metal paste smeared on a paper towel

As you can see that's dark as well.
Some metal grains in here as well

Also did an oil change and tire rotation. Have the material to do a transmission filter change but didn't get to it

I am glad I did this even though I just did it 5 months ago, those miles add up quick!!!
I have another event in August and will do the same fluid changes after as well. Hopefully some good insurance for the longevity of the parts.

Thanks to @CarbonSteel for starting me down this road with the beginning of this thread!!

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