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Discussion Starter · #1 ·
My truck is coming due for trans fluid/filter change. I'm thinking of doing it myself. It's a 2008 F250 with external filter. Is it a fairly straightforward drain/refill job or are there special tools & techniques required?
 

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All you can do is drain the pan and refill it. If you have an external filter, change it. The internal one doesn't need to be changed if there is an external filter. If there is only the internal filter, it needs to be changed at 60,000 miles.
 

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Which external filter? Mine has the metal coffee can filter. Replacing it is a snap. Drain pan, disconnect the quick fittings and then unscrew the rest. When installing new filter, I suggest putting some lube on the threaded side of the filter and be surprised how tight those threaded connections need to be in order to not leak.

I haven't the equipment to replace all the tranny fluid. Just as Mark said, just the fluid in the pan when you drain it. But I can titer down the fluid to clean it up. Not like it needs clean fluid, as the fluid is always very clean. Here is an example with easy math:

Imagine a container that holds just 10 quarts of dirty fluid and you want to replace it with clean fluid. Further, you can only drain 5 quarts out when you drain it ... which is 50% of the 10 quarts this container holds.

- First time you drain 5 quarts, refill and fluids mix ... fluid is now 50% clean fluid
cuz you've removed 5 quarts of 100% dirty fluid ... you removed 50% of all dirty fluid

- Next time you drain 5 quarts, refill and fluids mix ... fluid is now 75% clean fluid
cuz you've removed 5 quarts of 50% dirty fluid ... you removed just 2.5 quarts of dirty fluid ... 25%

- Next time you drain 5 quarts, refill and fluids mix ... fluid is now 87.5% clean fluid
cuz you've removed 5 quarts of 25% dirty fluid ... you removed just 1.25 quarts of dirty fluid ... 12.5%

And so forth. I stop at 75% clean because those external filters get tossed about every 30-40k miles I think. So, your running cleaner tranny fluid than most folks do I suspect.

Yeah its expensive cuz tranny fluid is $cha ching$, but I can do this in my driveway and its very simple. I like simple.
 

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yup.. simple rocks...

I wish you could just dump it all. as the juice they were spec'd for is becoming harder and harder to find- which made me have to mix what was in it with valvoline extended life that fairly recently received the rating...

I do run a diesel site remote filter by-pass filter, though I'm sure it's not needed it does add a layer of protection if the TC decides to give up the ghost... i guess... that's why i installed it, anyway... sounds good on paper, right?

If I was industrious as I once was, I'd build a kit that intercepted the cooler lines and split it into three smaller line that fed through three of the biggest amsoil 2um filters I could find, and I'd have to pre-charge those filters, too, which would be about the same for what you can drain out of the pan.. I'd have to warm the fluid, too, to keep that thermostatic bypass open... reason I'd do this? I read an article some months back about doing something similar, but with a single 2um filter- and it restored AT fluid w/ 200k mile use out of a sealed transmission to the same condition it was in when it went in it- laboratory proven... now here is the punch line: it's what get's into the fluid that wipes it and transmissions out... it isn't what happens inside the transmission (if temps are kept in check)... external contaminants is what depletes and condemns the fluid almost 100% of the time- or close enough to say EVERY time... point being? be careful while refilling that transmission NOT to get ANYTHING in it....

oh.. and don't overfill... it's easy to do.. aim for midway, or right between the cold fill full and low fill hot lines when the trans is at normal operational temperature (165~185*)...
 

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I read an article some months back about doing something similar, but with a single 2um filter- and it restored AT fluid w/ 200k mile use out of a sealed transmission to the same condition it was in when it went in it- laboratory proven...
Bullcrap.
now here is the punch line: it's what get's into the fluid that wipes it and transmissions out... it isn't what happens inside the transmission (if temps are kept in check)... external contaminants is what depletes and condemns the fluid almost 100% of the time- or close enough to say EVERY time... point being? be careful while refilling that transmission NOT to get ANYTHING in it....
Additional bullcrap.

That's part of it, but certainly not all of it.

There are additives in transmission fluid. Anti wear, anti foam, lubricity modifiers, etc. These get used up and wear out. The fluid itself gets sheared by use, which changes it's viscosity. There is no way to filter this back to the original.

Filtering is good, but there is NO WAY it replace scheduled fluid changes.
 
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Don't Holler At Me, man!!! :)

it's just what i read... written by white coats and painstakingly read by me on the count that dry reading ain't my forte'... It's funny that there are generally two ways to approach something- which are experience and then study... which is better? experience every time by my reckoning... which is more expensive? friggin' experience, man..

I got nuthin' but respect for you, Mark. I've read a lot of your posts across the interwebz specific to the 5R110(w) and w/o it I wouldn't know crap about it... That said, it's still a box of mystery and witchcraft that bolts to the back of an engine so far as I'm concerned.

I think I misrepresented the article spoken of above, anyway... what I think they were trying to impart is that the fluid was as clean as new- NOT that it wasn't depleted. The point 'they' were making is that the contaminants were absent.
 

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.. what I think they were trying to impart is that the fluid was as clean as new- NOT that it wasn't depleted. The point 'they' were making is that the contaminants were absent.
Now that I can agree with.
 

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Discussion Starter · #8 · (Edited)
Thanks guys. I'm familiar with the drain-refill-drain-refill-repeat technique from my Honda. On my old Taurus I opened the line to the trans cooler and then ran it until it stopped flowing and then refilled it. That supposedly got most of the fluid out. I'll probably do a couple pan drain/refill cycles. Can I use that Valvoline fluid previously mentioned? Is it compatible with the Ford fluid in the trans? How much fluid does it take for just a drain/refill?

Damn, those filters are pricey. Best price I've found is about $75 for a Motorcraft. There's another brand on Rockauto for about $45. Is this something that should be a genuine Motorcraft or will an aftermarket one be OK?
 

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How often you gonna change the filter? $75 every 60k shouldn't be a concern, but an unknown filter should be.
 

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Discussion Starter · #10 ·
It's every 30k for the external filter, if any. 60k for the internal, if there's no external. If there's an external, the internal filter, which is apparently just a screen, never needs changing. At least that's what I understand from lots of searching. The truck just went over 30k. We use it almost exclusively for towing our trailer so don't drive it much. It might be one of the lowest mileage 08s in existence. :)

But your point is well taken.
 

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It's every 30k for the external filter, if any. 60k for the internal, if there's no external. If there's an external, the internal filter, which is apparently just a screen, never needs changing. At least that's what I understand from lots of searching.
That is correct.
 
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