Brand New - 4wd Burning Smell

[Aerogt01]

I just purchased a 2020 Expedition in August, and right now it has about 2200 miles. I've used 4wd about three times for snowy roads (all low speed) and every time after just a couple of minutes a clutch/gear oil burning smell enters the cabin.

Originally I thought this was just part of break-in, but the most recent 4wd use was for about 20-30 minutes total and the smell stayed around for a LONG time. Almost the entire 30 minute 2H drive home. I called my dealer, and no one has heard of this. I looked under the truck, and can see a few oily spots on the back of the TCase housing, and at least one of them is definitely gear oil. Strange thing is, the housing actually looks to have small cracks in it. Maybe I'm just not used to seeing that surface finish.

Has anyone had a similar issue with the 4wd smell? I've searched quite a bit and can't hardly find anything.

 

[riphip]

Take back to dealer for sure!!

 

[Aerogt01]

Take back to dealer for sure!!

Yeah, that's gonna happen. I was just hoping someone had heard of this before. My luck I'd have problems on a brand new vehicle.

 

[Aspen03]

Maybe it got quite warm, thus the burning smell and also caused whatever finish is on it to crack from the heat? Id think it would take an awful lot to actually crack the housing and be a more substantial failure if it were. Definitely not normal obviously,

This is what keeps me from ever considering a new vehicle. I can't think of a single friend or family member who has bought new cars over the last 5-10 years that didn't have sort of annoying-potentially serious problem within a few months of ownership. That seems insane for the fact that some of these have mortgage sized payments on them.

 

[Soliyou]

I just purchased a 2020 Expedition in August, and right now it has about 2200 miles. I've used 4wd about three times for snowy roads (all low speed) and every time after just a couple of minutes a clutch/gear oil burning smell enters the cabin.

Originally I thought this was just part of break-in, but the most recent 4wd use was for about 20-30 minutes total and the smell stayed around for a LONG time. Almost the entire 30 minute 2H drive home. I called my dealer, and no one has heard of this. I looked under the truck, and can see a few oily spots on the back of the TCase housing, and at least one of them is definitely gear oil. Strange thing is, the housing actually looks to have small cracks in it. Maybe I'm just not used to seeing that surface finish.

Has anyone had a similar issue with the 4wd smell? I've searched quite a bit and can't hardly find anything.

the TC has no gear oil. It uses red transmission fluid.

can you post a picture of the oily spots?

 

[Aerogt01]

the TC has no gear oil. It uses red transmission fluid.

can you post a picture of the oily spots?

Absolutely. Lets see if this works. I didn't feel like driving up on blocks so here's the best I could do with a cell phone and utility light. Keep in mind - 4 months old, 2200 miles.

Editing so I'm not doxxing myself.

Driver's side
View media item 7284
Pass side
View media item 7285

 

[Aerogt01]

Quick update for anybody still interested.

Red had a service appointment yesterday. I have noticed that this burning smell happens only when the rear diff locks - I've spun the rear tires on ice in 2WD and smelled it right after. I also drove to the dealership in 4A and got a rear diff overheat warning (eLSD disabled message) when I went to re-start the truck in the dealership parking lot.
Unfortunately, the computer did not log the overheat/error, and the dealership "could not replicate" the issue.

So I asked them to change the fluid in the rear diff. They informed me that this was not covered by the warranty since they could not find an issue, and I said I would have to pay for the service if the fluid came out looking fine. Here is what the fluid looked like at 4.5k miles:
View media item 7320
Definitely darker than I would have expected, but it did not have any metal shavings or silver clutch particles floating in it, and viscosity looked good. They said this color was not out of the normal and I didn't want to push it, so I ended up paying the $200. Either way, I'm happy to have the 'break-in' fluid out and new fluid in. We'll see if the smell pops up again. If not, $200 well spent.

Besides, I was going to end up paying for this service sooner or later anyway. No matter what the manual says I am NOT going to treat this as lifetime fluid. That's just a bad idea.

 

[5280tunage]

Sorry to hear about the issues, sure hope it's okay now. That's also a pretty crappy response. Did you happen to take a picture of the message for them? I've made that a habit now, anytime I get a message, I snap a pic. I love how these computers track everything we do, but not their own issues sometimes.

Wish I could look at the code and see if it's intentional... Humm...

Also, anyone else not able to see a lot of images like this, I can't get to the posters link. The forum says I don't have permission to view the album.

 

[Aerogt01]

Sorry to hear about the issues, sure hope it's okay now. That's also a pretty crappy response. Did you happen to take a picture of the message for them? I've made that a habit now, anytime I get a message, I snap a pic. I love how these computers track everything we do, but not their own issues sometimes.

Wish I could look at the code and see if it's intentional... Humm...

Also, anyone else not able to see a lot of images like this, I can't get to the posters link. The forum says I don't have permission to view the album.

That's a great idea about taking a pic. I'll have to remember that. I assumed it would make sense for the computer to log it.

I was able to find the album setting to make it visible. Can you see it now?

 

[5280tunage]

Yup, working now, thanks. That appears a bit dark to me for 4500 miles, but i'm no lubricant-ologist. Generally when this fluid goes in, at least all of the diff fluid I've ever changes, it's pretty transparent and yellow. Unless you really get on this thing that seems a bit more opaque than i would expect. Did you get a sample of it?

I know some folks on here have their oil inspected by third parties. Not sure if they do all lubricants, but that might be worth it. If they come back and tell you the viscosity is way off, etc, you have something take back to the dealer, maybe get your $200 back but I doubt it.

Maybe the same guy on the assembly line that's not putting plugs in the chassis used engine oil in your diff, just kidding.