Expedition Max to Yukon XL?

[DontTaseMeBro]

Don’t get me wrong, the 6.2L is a beast of a motor and more than capable of doing what you need. You mentioned buying a used one - look into the service history of it and see if it had the DFM lifters replaced. At a time the dealer would just replace one bank of lifters and then the other bank would fail later on. I think they finally revised their TSB to just replace all of them at once.

6.2Ls have also been going through main bearing failures - most of them are early life - <10K miles. Though recently someone on the forum here had their 6.2L eat up the main bearings at ~50K miles. Do a search on this forum for 6.2 bearing failures. Forums exacerbate every issue, but there’s no denying you’re rolling the dice with a 6.2L when it comes to DFM lifters and main bearings.

I hear you on the DEF usage while towing, but you also mentioned you only do it 3-4 times a year, right?

The 3.0 Duramax isn’t perfect and no engine is, but at this point hanging out on this forum and also popping over to Duramax Forum once in awhile I have not heard of one single catastrophic engine failure on the 3.0. There is a teardown video of the engine on YT that is pretty popular but it’s evident from that video it was neglected and ran out of oil. There’s a few issues here and there that have popped up, but nothing like what we’ve been seeing on the 5.3/6.2 that has left many owners stranded and in need of a motor replacement.

Thanks. I've been doing the exact thing you suggested - checking service history on 2021's. I'm currently looking at two - one with 38k mile and the other with 42k. Neither show DFM lifter replacement or bearing failure. Just routine maintenance and checks. You are correct about the 3-4x towing the camper per year. So I guess in that respect I am sort of nitpicking against the 3.0. I have an account on the Duramax forum because I was pretty active in it during the time I owned my '22 Silverado. That being said, I'm going to have buyers remorse knowing that the LZ0 is coming in the Yukon. I was just thinking that a big 'ol NA American V8 would be a good choice in terms of running costs(excluding fuel ) and service. My previous daily was a Lexus GS F with the 5.0 V8 and currently own an E63 AMG with the 5.5 TT V8. God I love V8's haha.

 

[Marky Dissod]

Despite what anyone else thinks, if ATF exceeds 212F, GM / FoMoCo / ChryStellantis / whatever like it, because MpG improves.
MpG is NOT the prime concern, ESPECIALLY when towing.
Not only should you get that Ford Raptor's external ATF cooler -
If it doesn't come with a fan that you can turn on at will, add an externally controllable fan to it too.

Every time ATF exceeds 230F (in my experience) it needs replacing at next possible chance.
Pull over before 230F if possible - seriously, what're y'all trying to prove?
Start that video @ 10min40sec; that's when I'd've pulled over.
Then he abuses the ATF again @ 14min10sec - it's a press loaner / not his, he's making a video for your entertainment(?) ...
There's a cymbal rush @ 15min23sec, jerks celebrating victory ...
(Same applies to coolant - I'm too old NOT to avoid overheating.)

Instead of Tow / Haul mode's 1st and 2nd, have you tried simply using 1st?
This'd be in case the road is paved and 4Hi / 4Lo are a bad idea.

In terms of additional heat, I bet ecm / tcm tuning would be of any help (see what GM did?).
Specifically, when shifts are commanded, how quickly shifts take to start and complete, how much line pressure is applied, etc

You obviously found an edge case; is Ford really NOT interested in learning ANYTHING from this?
Did anyone bother to compare the twinturbo 3.5L against a Ford V8, both with the 10 speed?

 

[BlaineBug]

Good to hear regarding the trans temps. I'm looking at picking up a used 2021 Yukon so no break in necessary(though I've followed this procedure per the owners manual many times before). The 4Lo idea sounds intriguing. I've always had it in 4Hi.



Have had this TSB applied, no change. The trans is just not that good. If the fixes worked, then there wouldn't be multiple class action lawsuits currently being levied against Ford.

Which fix(es) did they apply?

 

[DontTaseMeBro]

Which fix(es) did they apply?

Flashing the TCU I believe. I haven’t bothered with the latest program because I already have seen posts in the Expy forum thread that state that theirs were worse than mine. They got the latest fix and it’s pretty much good other than for the typical clunkiness. That’s how mine is right now. Mine doesn’t flash any kind of error etc. Just doesn’t shift as good as the GM version.

 

[BlaineBug]

Flashing the TCU I believe. I haven’t bothered with the latest program because I already have seen posts in the Expy forum thread that state that theirs were worse than mine. They got the latest fix and it’s pretty much good other than for the typical clunkiness. That’s how mine is right now. Mine doesn’t flash any kind of error etc. Just doesn’t shift as good as the GM version.

There is the second bulletin about the CDF clutch drum moving and blocking some oil ports. In December I spoke with a Ford technician who stated that this was the most common failure - requires full disassembly of the transmission and replacement of specific parts with revised versions of the same. A re-program can't fix a mechanical "failure."

 

[15burban]

As @Marky Dissod mentioned that fluid needs to changed asap and it's possible no amount of flashes or reprogramming could save the way it shifts.

 

[Marky Dissod]

Over a decade ago, I cited pics like the one above on the Impala SS Forum. Most of the pics expired.
So I studied the ones that were left, and transcribed the following text:

176°F / 80°C ..... 100,000 Miles ... Ideal Automatic Transmission Fluid Temp
194°F / 90°C ....... 50,000 Miles ... Max Recommended Sustained Temp
212°F / 100°C ..... 25,000 Miles ... MpG improves / Pressure Drops
230°F / 110°C ..... 12,500 Miles ... Varnishes Form
Already dumb enough right? Not dumb enough yet? OK, dumber.
257°F / 125°C ....... 6,250 Miles ... Seals Harden
Dumberer?
275°F / 135°C ....... 3,125 Miles ... Clutches Slip
Duhuhuhuhuh ...
293°F / 145°C ....... 1,562 Miles ... Oil forms carbon, seals and clutches burn

Keep in mind that if the ATF temp sensor reads 230F, somewhere, some of the ATF is even hotter than that, idiot.

Here are very old pics that have survived over a decade (so far):

https://performanceunlimited.com/documents/img104.gif

(1st link works but pic is even bigger than Joseph's sig.)

 

[DontTaseMeBro]

There is the second bulletin about the CDF clutch drum moving and blocking some oil ports. In December I spoke with a Ford technician who stated that this was the most common failure - requires full disassembly of the transmission and replacement of specific parts with revised versions of the same. A re-program can't fix a mechanical "failure."

I know about the CDF drum. They never redesigned it. Problem will return eventually. Mine does not have those kind of symptoms. If mine was as catastrophic as that, I would have dumped my Expy long ago. As stated in my OP, it’s currently shifting well. Which is a sign that this is my opportune moment to move one before something breaks. I’m just over with Ford as this will be my last one for a while. Don’t have the time or patience to be without a rig for the next few weeks or even months. Between this and phaser issues, Ford Service is buried deep with nationwide parts shortages etc.

ETA: i stand corrected regarding the CDF drum. Looks like they welded the bushing/sleeve in it so it no longer can move. It moving is the reason why these transmissions have been failing in Fords. Ford transmissions run hotter than the GM ones and that extra heat is why the sleeve moves in the Ford ones and not the GM ones.

 

[DontTaseMeBro]

As @Marky Dissod mentioned that fluid needs to changed asap and it's possible no amount of flashes or reprogramming could save the way it shifts.

View attachment 421217

It’s been like this since I got it at 12k miles. The two times it got very hot didn’t make things worse whatsoever. That being said, fluid was changed last September. No metal was found nor did it smell burnt. Something to keep in mind, the 10R80 in a Ford runs hot even during normal operation - 208-215F. It will go up to 270F before the gauge turns red and throws a code. I never got it up that high. In fact, in the digital gauge cluster, it doesn’t even show the trans temp until it hits 260F. Modern ATF, specifically Mercon ULV was designed to run hot. It has a a flash point of 350F. That all being said, that’s not an excuse I’m comfortable with. Both times it got close to the red portion of the gauge. If it had done that, vehicle would have gone into limp mode and thrown a code. I don’t wanna chance it anymore.

 

[BlaineBug]

I know about the CDF drum. Mine does not have those kind of symptoms. If mine was as catastrophic as that, I would have dumped my Expy long ago. As stated in my OP, it’s currently shifting well. Which is a sign that this is my opportune moment to move one before something breaks. I’m just over with Ford as this will be my last one for a while. Don’t have the time or patience to be without a rig for the next few weeks or even months. Between this and phaser issues, Ford Service is buried deep with nationwide parts shortages etc.

I road in a Transit, it wasn't catastrophic, but the shifts were just harsh and delayed, if I remember it was primarily 3-4 or 4-3, I don't remember as it has been about 2 months since.