Ford 6F35: What have we learned?

[Smcatub]

Originally Posted By: SilverFusion2010

To the poster that complained about throttle delay... Most of the time when I hit this issue it is because the transmission is still in 2nd as I'm rolling up to a stop, but hasn't yet downshifted to 1st when I get back on the throttle. The "hesitation" is intentional to allow the tranny to get into gear. That's my theory anyway. I adjusted my driving style and have almost eliminated these "hesitations". Pretty much, stop at the corner before pulling out. This puts the tranny back in first and that big low gear will bark the tires when you punch it.

The big problem with the throttle delay isn't just that the car acts funny and is a bit annoying at stop signs. IMO it's outright dangerous. When you hit the gas, you expect the car to go. If it doesn't, it might leave you hanging out in traffic. Imagine trying to zip out to make a left onto a busy road and having the car just putter along, barely moving. Or trying to merge onto the highway and having the car groan and just coast along when you expect a surge of acceleration.

 

[bdcardinal]

My mom's 2014 Fusion Ecoboost AWD has the 6F35 trans and had its first issue yesterday. Well the issue ahs been present for a while, but I discovered a nice coating of ATF under the car when I did the first oil change Saturday. The side cover was leaking and on the Fusion it uses RTV in place of a gasket for the cover.

 

[Whimsey]

Originally Posted By: bdcardinal

My mom's 2014 Fusion Ecoboost AWD has the 6F35 trans and had its first issue yesterday. Well the issue ahs been present for a while, but I discovered a nice coating of ATF under the car when I did the first oil change Saturday. The side cover was leaking and on the Fusion it uses RTV in place of a gasket for the cover.

On the bright side she has a good son, it's warranty work and she'll get all early wear particles out of the trans due to the repair . This will most likely help the trans to last a lot longer versus following Ford's service schedule. I've had my wife's 2005 4.6 Explorer trans fluid exchanged every 25-35,000 miles since new. At ~163,000 it shifts great. The last ATF change the mechanic said the fluid in the pan was so clean he only did a pan drop and Motorcraft filter change. Whimsey

 

[SilverFusion2010]

Originally Posted By: Smcatub

Originally Posted By: SilverFusion2010

To the poster that complained about throttle delay... Most of the time when I hit this issue it is because the transmission is still in 2nd as I'm rolling up to a stop, but hasn't yet downshifted to 1st when I get back on the throttle. The "hesitation" is intentional to allow the tranny to get into gear. That's my theory anyway. I adjusted my driving style and have almost eliminated these "hesitations". Pretty much, stop at the corner before pulling out. This puts the tranny back in first and that big low gear will bark the tires when you punch it.

The big problem with the throttle delay isn't just that the car acts funny and is a bit annoying at stop signs. IMO it's outright dangerous. When you hit the gas, you expect the car to go. If it doesn't, it might leave you hanging out in traffic. Imagine trying to zip out to make a left onto a busy road and having the car just putter along, barely moving. Or trying to merge onto the highway and having the car groan and just coast along when you expect a surge of acceleration.

I get what you're saying, but since I started my complete stop policy I haven't had any scary moments cause by my car... now the idiots that drive around here on the other hand... 1 other thought occurs to me, and that is simply that you and I have evolved different driving styles because the tech changed. I grew up with Drive-by-wire, and I can tell the difference in the throttle response, so my driving bag of tricks expanded with little ways to compensate for how the drive-by-wire operates. I make a big left turn every morning to go to work up a hill from my apartment complex. That low 1st gear does the job getting me out into traffic safely and smartly. My 6F35 has been a solid transmission. I'm sorry to hear all these horror stories.

 

[SilverFusion2010]

Originally Posted By: Smcatub

I just got the wife's flashed for the throttle body issue and saw a big improvement. I'm hoping they made it a little less 'adaptive' and it keeps performing like it does right now. In a couple of weeks it's getting the first of a series of drain and fills with MaxLife with a switch to D6 planned if needed. It's got 52k right now so I can't comment on what's going to happen with high mileage 6F35's. But I don't want to find out - I'm hoping to convince her to trade it in once it's paid off. Unless I see a lot of high mileage 6F35's rolling around and it turns out all this worry was for naught. The biggest complaint I have about it is that it seems to go into neutral when braking or coasting. Has anyone else noticed this? If I need to get on it fast after coasting or braking for a while (like trying to swing out of a slow moving lane into faster traffic) it won't go for a bit, then slams into gear from high RPM. I know the slam can't be good for the tranny, but it's also unsafe - I'm trying to merge with traffic, I expect the car to go, but it's just sitting there. It's pretty dangerous if you're used to a car that goes when you hit the gas.

I just re-read this post. My 6F35 doesn't go into neutral when coasting, it holds the gear and provides light engine braking(I think it stays in gear and unlocks the torque converter) and downshifts as speed drops. I have the 3.0L V6 though, which Ford supposedly set up with a very aggressive fuel trim for MPGs, so it's possible it's just flat out programmed different. If I ease on the gas the car responds well, if I punch it hard it will downshift THEN I'll feel the engine pull. That sounds like what you're describing, but I've never felt a slam. Before it was rebuilt, I could come to a complete stop, hold stopped for several seconds, then shift into reverse. That shift felt like getting hit in the back, and I considered that a slam. Never felt anything close to that since the rebuild. The longest pause I have found happens in hard braking. If I'm rolling along at 60 and have to stand on the brakes down to 30, then get right back on it to zoom around the vehicle that cut me off, the car will be in too high a gear for the speed and rpm and will take a second or so to drop the 2-3 gears needed. That's acceptable to me. I don't know of any automatic that handles that scenario gracefully. To avoid it I just coast for a bit after releasing the brakes, then when I get back on the gas, the transmission has already shifted and I smoothly accelerate. These are my experiences with the 6F35.

 

[bdcardinal]

On my mom's Fusion, if you put the trans into "S" it will downshift as you slow down. If it is left in "D" it feels like it is in neutral.

 

[Smcatub]

Originally Posted By: bdcardinal

On my mom's Fusion, if you put the trans into "S" it will downshift as you slow down. If it is left in "D" it feels like it is in neutral.

I don't have a "S"port option on our shifter. BUT, after reading the owners manuals for 2010 and 2014 it looks like your sport and my 'Overdrive Cancel and Grade Assist' are similar. Maybe I'll try hitting the button on my shifter to enable that mode next time I need to make a quick maneuver.

 

[Hokiefyd]

I very much doubt the transmission is going into neutral. Compared with engine control programming that provides engine braking, some transmissions DO feel as if they're in neutral, even though they're in gear. It's really a function of whether or not the engine cuts fuel during coasting. I'm going to stereotype here: traditional "domestic" engine control programming usually does not cut fuel during coasting, at least to a large degree. The engine receives fuel during coasting, and it feels like the car will simply roll forever. Great for smooth driving. The Toyotas and Hondas that I've owned more aggressively cut fuel during coasting. It feels no different, really, than driving a manual. It requires one to be smoother with the throttle, but you get engine braking. You also get downshifting very quick, so as you slow down, the transmission's already downshifted, so you don't have to wait for it to find the right gear when you're ready to go again: it's already there. But there are more impulses into the cabin this way, especially if the driver isn't smooth with the go-pedal. Clearly, neither strategy is "right" or "wrong"; both ways work. I personally prefer one concept over the other, but both get the job done.

 

[SilverFusion2010]

160k miles on the fusion and still running strong

 

[dwcopple]

well, we have learned that GM/Ford should NEVER team up to build a transmission for one...

 

[SirTanon]

I dunno. While the 6F35 trans may not be the best trans out there, it certainly has its good points. I, for one, have found that the one in my car seems pretty responsive and smooth, and keeps my RPMs relatively low at cruising speeds. Yes, sure, it requires more attention.. but I find that doing a drain&fill approximately every 4th oil change does the job, and I'm under the car anyway. As to the 'shifting into neutral' vs 'cutting fuel' argument. My observation has been that when I'm cruising on the highway @ 70mph, and I tap the brakes to coast, or when I'm coasting down a decent hill, my Torque reports that I'm getting 512MPG (which is what it maxes out at), and the car stays in gear at relative RPMs, so it would seem that it's doing some kind of fuel cut-out, whether it's 100% or not.. There's some kind of fuel management going on. .. and for those counting, the trans in my fusion is the original 6F35, so mine is still going strong just a hair over 229,500 miles.

 

[panthermike]

Originally Posted By: SirTanon

I dunno. While the 6F35 trans may not be the best trans out there, it certainly has its good points. I, for one, have found that the one in my car seems pretty responsive and smooth, and keeps my RPMs relatively low at cruising speeds. Yes, sure, it requires more attention.. but I find that doing a drain&fill approximately every 4th oil change does the job, and I'm under the car anyway. As to the 'shifting into neutral' vs 'cutting fuel' argument. My observation has been that when I'm cruising on the highway @ 70mph, and I tap the brakes to coast, or when I'm coasting down a decent hill, my Torque reports that I'm getting 512MPG (which is what it maxes out at), and the car stays in gear at relative RPMs, so it would seem that it's doing some kind of fuel cut-out, whether it's 100% or not.. There's some kind of fuel management going on. .. and for those counting, the trans in my fusion is the original 6F35, so mine is still going strong just a hair over 229,500 miles.

I now think people have misjudged the longevity of the 6F35(I was one of them). I got rid of my '10 Fusion when it had 44K miles partially due to the fear of failure. I feel like I was overthinking the matter, it never slipped just had an occasional "flare". Plus, I was changing the ATF every 20K and using Lubegard. My feeling is the car is putting around town just fine still. Are there many actual documented failures of the 6F35?

 

[SOHCman]

Originally Posted By: dwcopple

well, we have learned that GM/Ford should NEVER team up to build a transmission for one...

Ba-dum ching!

 

[idanny76]

I know there hasn't been any activity since 2017 on this post. I purchased 3 weeks ago a 2012 Ford Fusion SEL 2.5L FWD 6F35
with a 126,000 miles on it. The first thing I did was a change the transmission oil with Mercon LV, change spark plugs, cleaned the throttle body, had new air filter and the dealership had already done the oil change. When driving it in the morning when the engine is cold, there is a hesitation mostly on the second gear and third. As soon as the engine and trans fluid heats up.... the problems goes away completely. It leads me to believe its not a transmission issue, since it works perfect after warming up.

I searched online and some say its a normal shifting with the Ford Fusions. I don't believe its the throttle body, because it works fine after warming up. I would assume if it was the throttle body sending wrong information it would happen all the time. Sadly I didn't read this post before doing the trans fluid change or I would have used the RED Line D6 fluid. I would hate to just drain the transmission of the new Mercon LV and spend another $60 on the Red Line D6 fluid. I was thinking of running it for at least 15,000-20,000 miles before doing the change. My concern is if that rough delay shifting in the morning time or when the engine is cold could cause damage to the transmission.

I had read that this transmission has a memory that it stores the driving habits and that its recommended to reset the Transmisssion Adaptive Tables. I used my OBD2 ELM237 WiFi reader with Forscan and cleared the tables. I did notice an improvement in shifting and even the 2-3 gear shift went away for a little and came back.

Should I be really concern about the hesitation in shifting, since it only last for about the first 20 to 30 minutes? If I turn off the car and drive it a couple of hours later it doesn't do it. So basically, once the engine has been ran it doesn't repeat the shifting problem.... Only once the engine has been sitting overnight.

 

[kstanf150]

I know there hasn't been any activity since 2017 on this post. I purchased 3 weeks ago a 2012 Ford Fusion SEL 2.5L FWD 6F35
with a 126,000 miles on it. The first thing I did was a change the transmission oil with Mercon LV, change spark plugs, cleaned the throttle body, had new air filter and the dealership had already done the oil change. When driving it in the morning when the engine is cold, there is a hesitation mostly on the second gear and third. As soon as the engine and trans fluid heats up.... the problems goes away completely. It leads me to believe its not a transmission issue, since it works perfect after warming up.

I searched online and some say its a normal shifting with the Ford Fusions. I don't believe its the throttle body, because it works fine after warming up. I would assume if it was the throttle body sending wrong information it would happen all the time. Sadly I didn't read this post before doing the trans fluid change or I would have used the RED Line D6 fluid. I would hate to just drain the transmission of the new Mercon LV and spend another $60 on the Red Line D6 fluid. I was thinking of running it for at least 15,000-20,000 miles before doing the change. My concern is if that rough delay shifting in the morning time or when the engine is cold could cause damage to the transmission.

I had read that this transmission has a memory that it stores the driving habits and that its recommended to reset the Transmisssion Adaptive Tables. I used my OBD2 ELM237 WiFi reader with Forscan and cleared the tables. I did notice an improvement in shifting and even the 2-3 gear shift went away for a little and came back.

Should I be really concern about the hesitation in shifting, since it only last for about the first 20 to 30 minutes? If I turn off the car and drive it a couple of hours later it doesn't do it. So basically, once the engine has been ran it doesn't repeat the shifting problem.... Only once the engine has been sitting overnight.

I’m glad you revived this thread.......changed the oil in my 2017 Lincoln today and was gonna change out the ATF(6F35). After watching several videos of where to re-fill the tranny, the cap plug to fill is not to be found on my unit .
there’s what seems to be a rubber tube with a small vent cap in the location that’s clamped on.
But nothing to remove to fill.....glad I didn’t drain it first 😳😳

 

[Lyman]

I’m glad you revived this thread.......changed the oil in my 2017 Lincoln today and was gonna change out the ATF(6F35). After watching several videos of where to re-fill the tranny, the cap plug to fill is not to be found on my unit .
there’s what seems to be a rubber tube with a small vent cap in the location that’s clamped on.
But nothing to remove to fill.....glad I didn’t drain it first 😳😳

You pull that vent cap off to fill the trans. Mine doesn't have a clamp. it just pulls off. I have 91,000mi on my 6F35 now and it is shifting good. When I first bought this car I babied it a little and the shifting was "wonky" I started driving it harder and the shifting improved a lot. I did a fluid exchange at 70k miles using mercon LV. Will do another at 100k

 

[kstanf150]

You pull that vent cap off to fill the trans. Mine doesn't have a clamp. it just pulls off. I have 91,000mi on my 6F35 now and it is shifting good. When I first bought this car I babied it a little and the shifting was "wonky" I started driving it harder and the shifting improved a lot. I did a fluid exchange at 70k miles using mercon LV. Will do another at 100k

I’ll see if I can get some good pics for ya to see.
The vent cap is tiny and under the cap is a very small white slotted plastic piece in the rubber boot. And the boot is clamped in place.

gotta love google !!!!
Found a pic of what mine looks like

 

[Greasymechtech]

Zip Kit - 6F35-ZIP

Seal critical circuit pressure losses in Ford 6F35 (Gen. 1 & 2) valve bodies with Sonnax Zip Kit 6F35-ZIP. No special tools required for installing these parts.

www.sonnax.com

6F35 - TransGo

transgo.com

July 2016 Issue - Transmission Digest

In This Issue Ford 6F35 Component Upgrades (Ford verses GM models – not even close)

www.transmissiondigest.com

 

[Whimsey]

We have 2017 2.3 EB Explorer with the 6F35. Changing the ATF is easier than doing an engine oil and filter change. An 11 mm plug on the bottom of the transmission to drain and to fill is through the vent under the air filter duct. The vent is easy to get to. It has a large yellow cap that is pressed in and pulls out. The vent tube is tall enough and wide enough to easily use a transmission funnel to add the ATF. Your vent/fill tube looks like Ford is serious when they say the ATF is good for 150,000 miles . I drained the factory fill at 12,000 miles and it was extremely silvery, no pink at all. 10,000 miles later it was still but less silvery and grey, no pink. Again 10,000 miles later it was much less silvery and slightly pinkish. This is a heavy and fairly powerful vehicle that has a smaller car transmission that appears to stress the ATF. Since changing the ATF is so easy I'm trying to maintain a ~20,000 mile drain and fill routine to hopefully maintain a longer tranny life.

 

[bdcardinal]

We have 2017 2.3 EB Explorer with the 6F35. Changing the ATF is easier than doing an engine oil and filter change. An 11 mm plug on the bottom of the transmission to drain and to fill is through the vent under the air filter duct. The vent is easy to get to. It has a large yellow cap that is pressed in and pulls out. The vent tube is tall enough and wide enough to easily use a transmission funnel to add the ATF. Your vent/fill tube looks like Ford is serious when they say the ATF is good for 150,000 miles . I drained the factory fill at 12,000 miles and it was extremely silvery, no pink at all. 10,000 miles later it was still but less silvery and grey, no pink. Again 10,000 miles later it was much less silvery and slightly pinkish. This is a heavy and fairly powerful vehicle that has a smaller car transmission that appears to stress the ATF. Since changing the ATF is so easy I'm trying to maintain a ~20,000 mile drain and fill routine to hopefully maintain a longer tranny life.

I still think it is annoying that the filter is deep in the case and can't be changed. I know they say it isn't needed but it would be nice.