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BlueWaffle

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Ford Bronco Automatic transmission fluid ATF analysis after 45k miles, 3.73 gears, 100lb per corner 35's 1000001776


"Off to a typical start" not bad!

When I picked it up.. the tech who serviced the bronco said that the trans filter was absolutely DISGUSTING.. so I kinda started to worry a bit lol.

In the days of old (which a great deal of people here seem to be stuck in lol) running 35s on 3.73s was... Hard on equipment we'll say.

I'm NOT stuck in those days.. and knew about the 10r's ratios years before I bought the bronco.. so I took a calculated risk. Turns out.. my calculations were correct. With the 1:1 ratio not being until 7th gear.. this ol slushbox provides MORE than enough reduction to run 35s without adding a bunch of premature wear*

*In my use case, at least.


My driving is a majority of what I'd consider rural. 50-60mph & minimal stop & go. I generally drive like a "normal" person.. but I'll let er eat some 0-60's on occasion.. really give it hell leaving toll-booths.. and whenever there's snow on the road I'll generally always get out and drive around town as sideways as I can in 4wd..




Living in the northeast.. our offroading is mostly slow speed rock crawl-y type stuff.. so I'm in low range 1st or 2nd all day.


35s & 3.73s may not be a match made in heaven for EVERYONE, but there's no reason to poo-poo on said combo.. it'll work for most people just fine.
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Jdidier

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I guess this was a fluid replacement and testing? At 45K? Why so early? And if you don't mind, about how much should I expect to pay for similar? Tks
 

Blakshukvw

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I guess this was a fluid replacement and testing? At 45K? Why so early? And if you don't mind, about how much should I expect to pay for similar? Tks
I’m surprised how many people think 45k is “early” for a transmission service. The 4r70 and 75 were always happiest with 30k to 45k at the most, intervals. I guess I’m just used to doing maintenance on my vehicles. Of course I keep them a long time. You should never follow the suggested interval specified by the manufacturer. They don’t care what happens to your vehicle long term. They just want to be able to say maintenance costs are “low.”
 

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Spiniker

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I guess this was a fluid replacement and testing? At 45K? Why so early? And if you don't mind, about how much should I expect to pay for similar? Tks
I did mine at 35k at the dealer. Which was the complete service. It included flushing the lines and cooler,dropping the pan and cleaning the magnets,replacing the filter, cleaning pan and around solenoids,replacing the pan gasket for $900.
 

2021FordBronco2

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1000001776.webp


"Off to a typical start" not bad!

When I picked it up.. the tech who serviced the bronco said that the trans filter was absolutely DISGUSTING.. so I kinda started to worry a bit lol.

In the days of old (which a great deal of people here seem to be stuck in lol) running 35s on 3.73s was... Hard on equipment we'll say.

I'm NOT stuck in those days.. and knew about the 10r's ratios years before I bought the bronco.. so I took a calculated risk. Turns out.. my calculations were correct. With the 1:1 ratio not being until 7th gear.. this ol slushbox provides MORE than enough reduction to run 35s without adding a bunch of premature wear*

*In my use case, at least.


My driving is a majority of what I'd consider rural. 50-60mph & minimal stop & go. I generally drive like a "normal" person.. but I'll let er eat some 0-60's on occasion.. really give it hell leaving toll-booths.. and whenever there's snow on the road I'll generally always get out and drive around town as sideways as I can in 4wd..




Living in the northeast.. our offroading is mostly slow speed rock crawl-y type stuff.. so I'm in low range 1st or 2nd all day.


35s & 3.73s may not be a match made in heaven for EVERYONE, but there's no reason to poo-poo on said combo.. it'll work for most people just fine.
This makes me feel a lot better as I have the same on mine and was a bit worried since sometimes the trans shifts a bit funky but I think its probably just the trans logic as it isn't tuned for the bigger heavier tires. Now my question would be how do the diffs look?
 

DALOLA

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For anyone who thinks this is "early", check the Ford severe service maintenance schedule... 😉 (the way most of us drive our Broncos, most of us should be following the severe schedule...)
 

3People1Body

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I just did my tranny fluid change at 80k. Fluid was burnt and filter was dirty.
I run mine hard… really hard. I recommend changing way earlier now haha
Hey Popo... Did you happen to video that? Or is it straight forward? I'm in the <60k range, diffs and transfer fluids have been changed... Just the tranny left.
 

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23OBX2.7

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Saw a youtube on how using eco ode in city massively accelerates trans wear and kills fluid life.
 

popo_patty

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Hey Popo... Did you happen to video that? Or is it straight forward? I'm in the <60k range, diffs and transfer fluids have been changed... Just the tranny left.
I did not:( I cheated and went to my friends shop due to some injuries preventing me from doing car maintenance for a min
 

23OBX2.7

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I did not:( I cheated and went to my friends shop due to some injuries preventing me from doing car maintenance for a min
I just did my tranny fluid change at 80k. Fluid was burnt and filter was dirty.
I run mine hard… really hard. I recommend changing way earlier now haha
Thats way to long interval even with normal driving. At 20K i will get PPE pan and new filter and thereadter drop the 7 qts fluid every 12K miles to keep fresh.

First change should be max 40K miles IMO unless its a lease then lifetime applies haha.
 
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BlueWaffle

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I guess this was a fluid replacement and testing? At 45K? Why so early? And if you don't mind, about how much should I expect to pay for similar? Tks

As another member noted, Ford's recommended maintenance schedule is the ABSOLUTE BARE MINUMUM .. and honestly it barely even meets that IMO.

To quote myself from another thread..


"Ford engineers their products with the overall goal of 95% of them lasting 150k miles (this is direct from a retired Ford engineer, the man responsible for the creation of the FX4 package)

Obviously deciding what the maintenance schedule will be is part of engineering.. but the marketing department has an ever increasing amount of say in it..

With how expensive life has became in the past 20 years or so, more manufacturers are going with either extremely high mile interval or so-called "lifetime" fluids simply because 'low cost of ownership' is becoming more and more important & appealing to prospective buyers.

If an individual wants a longer than average useful life of their Ford vehicle, it's in their best interest to change all their fluids much more frequently than what Lord Henry recommends. Plain and simple."


TLDR: Ford only wants your bronco to last 150k, if you expect more.. change your fluids more.


Maintenance schedules for those of us who want to be "in it for the long haul" should be considered the same as the maintenance schedules for vehicles sold from the 90s & early 00's... Pretty much 50k miles max for drivetrain fluids and 5k-7.5k for engine oil.

Considering my trans filter was as filthy as it was at only 45k... It presumably wouldn't of taken too many more miles before the fluid started to turn just as filthy & abrasive.


This makes me feel a lot better as I have the same on mine and was a bit worried since sometimes the trans shifts a bit funky but I think its probably just the trans logic as it isn't tuned for the bigger heavier tires. Now my question would be how do the diffs look?
The diff fluids were "VERY OBVIOUSLY used" per the tech.. but no water intrusion or anything out of the ordinary for a "break in fill" with that many miles.
 

N8do

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I am at the 23K mark, and have done both diffs and T-case. I have the fluid, and a PPE pan on hand, waiting for my opportunity to get under and change it out. Thus far the oil was first changed at 2K and every 5K after that. I did wait till 20K ish before doing the diffs and case.

So far the fluids were not scary coming out, and the magnets did their job. I did check the fluid level on the 10R60 and it seemed pretty light colored and higher level than expected. It was at 2 1/2 at 150 degrees. If I'm not mistaken the manual says between 3 and 4 at op temp 175-215? The good thing with the PPE shallow pan, it will hold more fluid over the OEM.
I steered away from the deep pan due to it makes it closer the the rocks. I did not go with the additional transmission bash plates beyond the RCI crossmember plates. they are the only armor I am getting scared up thus far, so GREAT investments. The Badlands has things covered well from the start. Only had to add a few more item in the aft suspension area.
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