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Brian_B

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Got around to the 60k service and change out of all the fluids.

FDU had been changed at 50k for troubleshooting
The rear end was changed at 25k
The T-Case and 7MT changed at 15k

The last time I changed the FDU it looked nasty - tons of metal wear (no shavings, just sand). And about 5k miles ago I went from 35" to 38" tires, so I was expecting the worst.

But it looked fine - almost brand new in fact. Very little metal wear. On the rear end too - which had many more miles on it. Both looked great, the fluid was still mostly transparent (synth 75-140)

The T-case and transmission looked ok as well - no fluid analysis, obviously, the fluid had darkened in both a good bit, but nothing unusual. The fluid change did help the rough shift into 2nd gear I was having - not sure if the fluid was starting to break down or what. Used the same fluid in the 7MT I had used the first change out (Redline MT LV 70/75)

Found one wiring harness pulling loose (passenger parking break). Nothing else of note really.
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Thanks for the write up. I need to change my front differential this year. The front differential was changed twice the first year I had it.
 

murphtron

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Whoops thx for the reminder! Aside from oil every 5k, I’ve changed no fluids. Bronco 2.7 autoT is at 45k miles and perhaps 2k offroad.
 

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So besides oil change I have done no other fluid changes.
What should I have done at 21k, IYO?
@Brian_B
 

Nc211

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Got around to the 60k service and change out of all the fluids.

FDU had been changed at 50k for troubleshooting
The rear end was changed at 25k
The T-Case and 7MT changed at 15k

The last time I changed the FDU it looked nasty - tons of metal wear (no shavings, just sand). And about 5k miles ago I went from 35" to 38" tires, so I was expecting the worst.

But it looked fine - almost brand new in fact. Very little metal wear. On the rear end too - which had many more miles on it. Both looked great, the fluid was still mostly transparent (synth 75-140)

The T-case and transmission looked ok as well - no fluid analysis, obviously, the fluid had darkened in both a good bit, but nothing unusual. The fluid change did help the rough shift into 2nd gear I was having - not sure if the fluid was starting to break down or what. Used the same fluid in the 7MT I had used the first change out (Redline MT LV 70/75)

Found one wiring harness pulling loose (passenger parking break). Nothing else of note really.
Just my own opinion, but I think most wear happens in the first 3,000 miles of a new vehicle, and you live with it until you change the fluid at the stated manual intervals, thinking you were getting close to viscosity breakdown. I say that because when I changed my transmission pan at 4,000 miles, it had plenty of glitter in the pan with a black filter. Drove fine, no indication of concern (which you wouldn’t be thinking about at just 4,000 miles in general), but that stuff wasn’t going where. I bet if I pulled it now at 13,500 miles, it’ll look just fine.
 

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Brian_B

Brian_B

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So besides oil change I have done no other fluid changes.
What should I have done at 21k, IYO?
@Brian_B
I would default to @CarbonSteel - he has an excellent thread about fluid changes here someplace

But off the cuff - the Dana diffs love to “break in” and they get tons of wear material early on. They say it’s not bad for them, but it’s a significant amount - my first rear end was nasty looking, and when I did my front end at 50k there was more metal grit (like sand) than oil, it looked like I had poured out a lava lamp

The tcase and trans - probably more than fine at the recommended interval unless you suspect something is up (rough shifting or abnormal noises, etc)
 
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Brian_B

Brian_B

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Just my own opinion, but I think most wear happens in the first 3,000 miles of a new vehicle,
I suspect you are right.

I’ll also say there would be a huge difference in a manual vs auto - in an auto the fluid does a ton of work, in a manual it’s just there to keep things wet.
 

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Brian_B

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I'll also note - I did not flush the coolant or breaks/clutch. Only a bit more than 2 years on this thing, and both fluids still look good in the reservoirs. I did do an oil change with this, but I do that every 5k +/- anyway, and nothing to note there.

This puts all the driveline fluids back on the same schedule, as they had been done at various spots before for various things.
 

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For anyone wondering, changing brake fluid is needed because it is hygroscopic and absorbs water, which lowers the boiling point.

I was on a motorcycle ride on the northern entrance to California Hwy 1 that had a bunch of 15 mph curves. Imagine my surprise when the brake lever went all the way to the grip and I had no brakes …
 

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I used some test strips to test pH of both the coolant and brake fluid at 30,000 miles and both tested at the almost new end of the scale. Any reason to change them yet if that’s the case?

On the diffs, they were pretty nasty on my Wildtrak at 3k but at 10k there was maybe 25% as much metal on the magnet, if that. Could be in part because I changed to Amsoil severe gear 75w-140 at 3k, but I agree most of that break in wear is probably happening in the first few thousand miles.
 
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Brian_B

Brian_B

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I used some test strips to test pH of both the coolant and brake fluid at 30,000 miles and both tested at the almost new end of the scale. Any reason to change them yet if that’s the case?
I don't think so, but my opinion isn't expert for sure.
 
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B22-2023

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