Expedition Max to Yukon XL?

[DontTaseMeBro]

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.

I appreciate the feedback. Kind of ironic to get more replies here regarding my experience with our Expedition then in the Expy forums. Overall, I'm ready to turn over a new leaf and dive into GMC ownership. Been a Ford guy for almost 10 years now.

 

[BlaineBug]

I appreciate the feedback. Kind of ironic to get more replies here regarding my experience with our Expedition then in the Expy forums. Overall, I'm ready to turn over a new leaf and dive into GMC ownership. Been a Ford guy for almost 10 years now.

‍

 

[15burban]

Modern ATF, specifically Mercon ULV was designed to run hot. It has a a flash point of 350F

I'm not well versed in fluids but I don't think it's all about the flash point. I'm sure the fluid loses some of it's properties well before the flash point. Along with other parts of the transmission (seals, gaskets, etc) before the flash point of the fluid is reached. Just a quick search shows that the ac delco dexron vi used in the 6 speeds has a flash point of 356F. I'm not saying your transmission can't run that high of a temperature without potentially causing harm but I definitely wouldn't want to be the one to find out.

Edit dexron vi has a flash point of 356 not 256.

 

[BlaineBug]

I'm not well versed in fluids but I don't think it's all about the flash point. I'm sure the fluid loses some of it's properties well before the flash point. Along with other parts of the transmission (seals, gaskets, etc) before the flash point of the fluid is reached. Just a quick search shows that the ac delco dexron vi used in the 6 speeds has a flash point of 256F. I'm not saying your transmission can't run that high of a temperature without potentially causing harm but I definitely wouldn't want to be the one to find out.

It's all about fuel mileage, at the expense of premature failures. For the climate!

 

[15burban]

It's all about fuel mileage, at the expense of premature failures. For the climate!

For the climate! Although the climate doesn't pay for my repairs so my trans thermostat is deleted and I run 5w30 in the 5.3.

 

[DontTaseMeBro]

I'm not well versed in fluids but I don't think it's all about the flash point. I'm sure the fluid loses some of it's properties well before the flash point. Along with other parts of the transmission (seals, gaskets, etc) before the flash point of the fluid is reached. Just a quick search shows that the ac delco dexron vi used in the 6 speeds has a flash point of 356F. I'm not saying your transmission can't run that high of a temperature without potentially causing harm but I definitely wouldn't want to be the one to find out.

Edit dexron vi has a flash point of 356 not 256.

Oh I totally agree. It running “safely” at the temps that mine hit is very concerning. On top of that, the fact that there are mods to mitigate this(raptor trans cooler plus a lower temp thermostat) is undeniable proof that Ford half-assed the design of the drivetrain.

 

[PPK_]

I have a ’22 f150 and a Nov build ’23 Tahoe. Ford tranny is 195 degrees at temp and the Yukon runs 144.

ford shifts like a an old drum shifted Honda 90… without using the clutch. It interesting that the GM shifts like butter.. the ford whines a higher too. Not all worn out either.. ford has only 7k on it and GM on its second tank…

 

[DontTaseMeBro]

Anyways, not to thread bump, but moving on - I'm looking for some more feedback from those who have a 6.2 and tow a 6000-7000k lb TT? How has your experience been? More then enough power? If you had to do it again, would you do dmax instead? That kind of stuff. Also, I see that there a split amongst those who say that air suspension is necessary vs those who say it's really not if you run a wds? As mentioned, I run a Blue Ox. Here is what my setup currently looks like with it. Very little sag in the back. Approx 1.5" in the rear.

 

[StephenPT]

Here’s my setup - Yukon XL SLE - stock suspension - Camco EAZ Lift w/ 800lb bars. Air suspension might be nice, but honestly it’s more stuff to break long term and it runs just fine without it.

 

[BlaineBug]

You can always add those inflatable air spring helpers to the inside of any coil spring for some additional support without altering anything else at all.