Transmission Flush, or simple drain and fill?

[waflyboy]

On 8/18/2022 at 10:36 AM, akirby said:

Let the dealer do a fluid swap with the machine using the cooler lines.  Gets 97% of the old fluid and runs about $200.

 

I read in another thread that  @colinc755 suggested that the 8f35 doesn't do well with flushes, and recommends just doing a sump drain and fill. I'm planning to take my Edge to the dealer to change the fluid, and I know they are going to recommend flushing it. @colinc755 could you expand a little on this? (For my own knowledge and so I can have some defense for requesting a sump drain-n-fill only.

[colinc755]

1 hour ago, waflyboy said:

 

I read in another thread that  @colinc755 suggested that the 8f35 doesn't do well with flushes, and recommends just doing a sump drain and fill. I'm planning to take my Edge to the dealer to change the fluid, and I know they are going to recommend flushing it. @colinc755 could you expand a little on this? (For my own knowledge and so I can have some defense for requesting a sump drain-n-fill only.

Yeah so this whole idea generally comes from the 6F35 era. That was Ford's previous 6-speed that was found in everything and many outspoken ford techs like Ford Tech Makuloco stated that they found full flushes agitate these transmissions too much and can lead to issues. This was said to be because the transmissions are very sensitive with the clutch packs and have adaptive software that changes shift patterns based on fluid conditions. Changing too many properties of the fluid at once could cause some damage while the software catches up. The reason I apply this logic to the 8f35 is because of how similar it is to the 6f35 in that they pretty much share architecture and durability of components. A sump fill will allow for all of the preventative compounds that you need for excess ware to be refreshed, while allowing the transmission to still work under the patterns it has developed over time. Granted I don't have anything specific to prove this, and it's not nearly as much of an issue on cars that are well maintained. When I post on forums, I never know what the state of a persons vehicle is and with that mindset a sump drain is always preferable. I would hesitate to do a full flush at anything that is 60K+ and has had no preventative maintenance. For my own vehicles, I have always done sump drains and have found that my almost 70,000 mile transmissions shift better than other peoples 20,000 mile transmissions. Ultimately the best decision will come down to what you and the tech decide is the best for you specific vehicle, I am personally super cautious given the reputation ford transmissions have. Hope that helps!

[waflyboy]

Thank you for your insight! It makes sense and I really appreciate you taking the time.

 

Unfortunately, our 2019 has 62K miles and I don't think the transmission fluid has ever been serviced. We bought it 2 years ago with 20K miles on it and have taken it to a dealer for oil changes - so far as I know they never mentioned the need for transmission fluid service. And the official consumer-level Ford maintenance schedule simply says to inspect the fluid and "consult with the dealer for requirements" every so often. It never struck me as odd to have a long service interval, because our 4Runner's first transmission fluid service came at over 100k - and it's always worked incredibly well.

 

We really like the Edge, but the transmission has always felt funny - like it's shifting at the wrong time or shifting roughly. We had a software update around late 2020/early 2021, but I'm not sure it changed anything. I'll likely take your recommendation in an attempt to prolong the transmission life. Thanks again.

[colinc755]

On 10/10/2022 at 1:44 AM, waflyboy said:

Thank you for your insight! It makes sense and I really appreciate you taking the time.

 

Unfortunately, our 2019 has 62K miles and I don't think the transmission fluid has ever been serviced. We bought it 2 years ago with 20K miles on it and have taken it to a dealer for oil changes - so far as I know they never mentioned the need for transmission fluid service. And the official consumer-level Ford maintenance schedule simply says to inspect the fluid and "consult with the dealer for requirements" every so often. It never struck me as odd to have a long service interval, because our 4Runner's first transmission fluid service came at over 100k - and it's always worked incredibly well.

 

We really like the Edge, but the transmission has always felt funny - like it's shifting at the wrong time or shifting roughly. We had a software update around late 2020/early 2021, but I'm not sure it changed anything. I'll likely take your recommendation in an attempt to prolong the transmission life. Thanks again.

Yeah I would be lying if I said I was not in a similar boat with general transmission quirkiness. My 8f35 still surges and bucks every once and awhile even after the software update. There is one hill near where I live that is pretty steep and has a 25mph speed limit up it, the car just surges between 1 to 2 and 2 to 1 the entire way up.

 

Mostly what it comes from is that Ford took a 6f35 and added a new gear between the old 1 and 2 and added an additional overdrive between the old 5 and 6. Problem is the 6f35 was notorious for already having a rough 1 to 2 so throwing another gear in there made the problem even worse. The new gears are so close to the old ones in ratio that the car cannot stay in them for long and has to jump to the next gear really quickly. If you let off the throttle during that process, it'll surge and buck. That is why the vast majority of issues are around the 25mph mark too, the overdrive gears in these are amazing.

 

What frustrates me the most is that Ford recognized this and converted the software in the 2022+ ST models to skip the new 2nd gear, making it an artificial 7-speed transmission. This has made the newer ST's amazing to drive, and Ford has no plans of porting that software to any older ST's or 2.0's so we are stuck. Keeping up on fluids will help those quirks just remain as quirks and not endless damage. 

[waflyboy]

To add to the conversation:

I visited our local Ford dealer yesterday and requested a drain and fill. The service writer said that it wasn't recommended until 150k miles, but I ask them to do it anyway. We also discussed the weird shifting (occasional "bucking" / hard shifting), and he started to mention all kinds of things that we could to try to correct that (at my expense, of course), but it really didn't sound like he was familiar with this complaint on the Edge. Ultimately, I just had the fluid changed (drain and fill, as discussed). I don't think they did anything with the software, but I swear it seems to shift smoother. Not sure if it's in my head or if the new fluid is helping. For what it's worth, the tech said that the existing fluid appeared "normal." 

Thanks again for the info and help.

[Sjej]

how should i go about doing this

 

A. drain and fill once, and leave it (so i drain like 5qt with a warm trans, then fill with 5 qt) and just do this each 30k miles

 

B. drain out as much as i can, fill the amount that was drained (so i drain 5qt, fill 5qt), and drive the car to warm the trans up and repeat until ive drained out ~12qt

 

ive seen mixed opinions. this is a car with 146k miles and i have NO clue when the trans fluid was last changed, but it's brown now and definitely needs changing. but besides that, is there another way i should go about doing this?

[1004ron]

7 hours ago, Sjej said:

how should i go about doing this

https://www.fordedgeforum.com/topic/30312-8f35-fluid-change-tips/?tab=comments#comment-223013

[Sjej]

13 hours ago, 1004ron said:

https://www.fordedgeforum.com/topic/30312-8f35-fluid-change-tips/?tab=comments#comment-223013

 

i appreciate it but i havent really been able to find a clear answer. i have the '10 with a dipstick.

i think i am just going to drain and fill sometime next week, give it a few months and repeat until i've exchanged all the fluid. but i wont do it all at once, maybe like a month in between. thats all im getting from these threads. fluid is pretty brown, idk about the smell. also to the mod who moved my post i appreciate it, i didnt find this thread when searchin lol but its very helpful

 

it is slipping ocasionally so i do not wanna risk making it worse by exchanging all 12qt of fluid in one day. this slipping is only when its cold and it's usually just once per drive. ive never had it happen more than once. im hoping its nothing worse than that...

[DILLARD000]

On 11/20/2022 at 8:30 PM, Sjej said:

...havent really been able to find a clear answer

...'10 with a dipstick

...going to drain and fill  ...repeat until i've exchanged all the fluid  ..wont do it all at once, maybe like a month in between

...fluid is pretty brown  ...slipping ocasionally so i do not wanna risk making it worse by exchanging all 12qt of fluid.

Your plan sounds reasonable; I would drain+refill at least 4 times to get rid of that old brown ATF.

Draining+filling Tranny on these is easy+quick; definitely should be done every 4yrs\33kMiles.

Recommend using a premium FullSynthetic MerconV compatible ATF like AmsOil# SSMVS.ATF1g.

Consider using 1qt of Lucas Transmission Fix.

Also consider disconnecting battery for 15min, then reconnecting & driving conservatively to let PCM relearn tranny shift points.

 

Edited November 23, 2022 by DILLARD000

[1004ron]

On 4/8/2020 at 2:23 PM, Cerberus said:

I had a similar problem with slotted rotors on my old 2011 Fusion sport.

I figured out that it was the slotting of the rotor that was causing the noise, it sounded somewhat like a bad wheel bearing or flat spotted tire but only while on the brakes.

Don't be surprised if the new ones do the same thing..

 

You're right, the new replacement rotors did the same and I stuck it out longer than I should have and now have solid high carbon rotors and very happy with them.

[Sjej]

9 hours ago, DILLARD000 said:

Your plan sounds reasonable; I would drain+refill at least 4 times to get rid of that old brown ATF.

Draining+filling Tranny on these is easy+quick; definitely should be done every 4yrs\33kMiles.

Recommend using a premium FullSynthetic MerconV compatible ATF like AmsOil# SSMVS.ATF1g.

Consider using 1qt of Lucas Transmission Fix.

Also consider disconnecting battery for 15min, then reconnecting & driving conservatively to let PCM relearn tranny shift points.

 

 

thank you, i will do so

i use full synthetic, expensive but worth it to me. what does the transmission fix do?

i also did disconnect the battery when installing a new intake the other day. no slipping since then, should i still do it each time i drain & fill?

[DILLARD000]

14 hours ago, Sjej said:

 

thank you, i will do so

i use full synthetic, expensive but worth it to me. what does the transmission fix do?

i also did disconnect the battery when installing a new intake the other day. no slipping since then, should i still do it each time i drain & fill?

LucasTransmissionFix basicly is a viscocity additive; silightly thickens the ATF which helps transmission shift smoother\quicker.

Click here for YouTube test of LTF; have seen several of this guys product reviews, seems honest enough.

It's a judgement call; if the new ATF & BatteryReset has fixed problem to your satisfaction, I'd probably not use the Lucas; easy enough to add later.

No, don't reset the Battery every time; if the shift points are where you like them, leave it alone.

Edited November 24, 2022 by DILLARD000

[Sjej]

7 hours ago, DILLARD000 said:

LucasTransmissionFix basicly is a viscocity additive; silightly thickens the ATF which helps transmission shift smoother\quicker.

Click here for YouTube test of LTF; have seen several of this guys product reviews, seems honest enough.

It's a judgement call; if the new ATF & BatteryReset has fixed problem to your satisfaction, I'd probably not use the Lucas; easy enough to add later.

No, don't reset the Battery every time; if the shift points are where you like them, leave it alone.

Ok good to know. I’m gonna go do my first drain and fill and disconnect the battery then take it on a test drive. If any slipping occurs with new fluid I will try the transmission fix

[1004ron]

In a couple of months I'll be at 92K miles and plan to do the second drain and fill of the transmission.

 

Where's the best deal on fluid?

 

Amazon 5qrt X 2 = $74.66 (incl shipping and tax).

 

RockAuto 5qrt X 2 = $68.44 (incl shipping and tax).

 

 

[kruzr1]

I actually got my fluid at the dealer for $6 a quart which was cheaper than everyone else. I used the motorcraft ULV fluid for my vehicle. 

[Jw23]

Hello all, 

 

Had my MKX in to an independent shop today for an alignment, and they noticed that the trans fluid was pretty dark during the vehicle inspection. I verified it when I got home and noticed the same. I bought it at ~49,000 miles, and it currently has 89k on it. To my knowledge, the fluid hasn’t been changed to this point, and I’m not sure whether I should go with a transmission flush or just a simple drain and fill. I’m finding conflicting answers for the 6F50, so I was wondering if any of you have experience on this front. Any advice is appreciated, thanks!

[1004ron]

Drain and fill is what I do every +- 50K miles.

 

2015 Ford Edge Sport 2.7 FWD Transmission (transaxle) Service - Transaxle (FWD) - Ford Edge Forum

[dabangsta]

Drain and fill is the way to go. If it has been 90k miles, you might want to do multiple drain and refills (it takes 3 per the Ford manual to get most of the fluid changed that way).

 

Mercon LV gets dark fast. Ford issued a bulletin about it 2 years after they started shipping vehicles with it. The dye it uses goes away pretty quickly (like Royal Purple in some uses). Some Mercon V stays red longer, but most of it is dark after 10k miles, and even with 3 or 4 drains, it will likely stay pretty dark, with a hint of red after the last change.

 

As long as it doesn't smell burnt, isn't brown or have a lot of suspended solids, shouldn't be an issue.

[HellRat]

On 8/7/2022 at 11:04 AM, kruzr1 said:

Thought I would post this here as a comparison/reference.

Do you have a link or something I could get to the workshop manual, trying to do a fluid change on my 2109 edge st as well

Edited October 30, 2023 by 1004ron

[bigmac]

I was able to reattach the rubber funnel to the transmission fill hole using locking needle-nose pliers on the snap ring mentioned by Colinc755. This made reassembly quick after refilling the transmission fluid on my 2022 Edge. I was not able to use regular need-nose pliers for reassembly, only for removal of the funnel.

[colinc755]

10 hours ago, bigmac said:

I was able to reattach the rubber funnel to the transmission fill hole using locking needle-nose pliers on the snap ring mentioned by Colinc755. This made reassembly quick after refilling the transmission fluid on my 2022 Edge. I was not able to use regular need-nose pliers for reassembly, only for removal of the funnel.

That’s good to hear that my struggles with getting it back on weren’t just a lack of skill ?. There really isn’t a whole lot of room. 

[John 6567]

Hey I just want to acknowledge Kruzer1 Post on August in 2022. The 8F57 was a breeze in the ST (2019). 

 

Go under your car take the fabric cover off the driver's side you don't even need to remove it completely. 8mm I believe. Then there's the 14mm drain plug. Wait, take off the front most intake tube you'll see the breather and clamp attached to transmission. There's actually no videos or free documentation online so I was skeptical. Drained fluid, then poured a little ULV in the 1 inch hole. You need channel locks to get it off. Waited a minute and it trickled out. Great. 

 

Measured what came out with old gallon containers of coolant. About 5.5qt bought the 6 pack so it was perfect. Wished I did have 7qt though. Locked back up. Already have a monitor so it did take 20 min to get the transmission around 200. The slipping in 5th or 28-38mph is gone. I did reset the learning too though so it's debatable which helped more. Old fluid was dirty so it surely helped.

[bogmanglen]

Thanks to Colinc755 for a terrific write-up.  As so often happens, knowing that a problem like this is coming gives you plenty of time to think about solutions.

 

I was able to grab the snap ring with needle-nosed vise grips, and lock it open.  The funnel came right off, and was readily re-installed using this method.

 

On another note, am I OK to drain the fluid cold, then just add the same amount back in cold?

Thanks

 

 

[bobdabildr]

On 9/22/2019 at 12:31 PM, erikrichard said:

Ford's maintenance schedule says to replace fluid for the first time at 150k miles. Not sure if it's a good idea to wait so long, but there it is. I'd drain/refill without any hesitation whatsoever if I were you.

I just changed  my 2012 3.5 with 162,000 miles . I couldn't  believe  how brown it was. I think  every 50,000 would be good.  I'll wait just a bit and do it again. I've been  doing a deep  maintenance to get everything  synced out.  Drvrs side 1/2 axle. Oil. Trans fld. Pwr srng fld. 4 rotors and ceramic  pads. Shalom

[1004ron]

7 minutes ago, bobdabildr said:

I just changed  my 2012 3.5 with 162,000 miles . I couldn't  believe  how brown it was. I think  every 50,000 would be good.  I'll wait just a bit and do it again. I've been  doing a deep  maintenance to get everything  synced out.  Drvrs side 1/2 axle. Oil. Trans fld. Pwr srng fld. 4 rotors and ceramic  pads. Shalom

Welcome.

 

What Model/Year/FWD/AWD ? - please add that to your profile signature - https://www.fordedgeforum.com/settings/signature/

 

Add to your list the PTU and RDU.