Neutral towing

[jro58]

I have a 2019 lariat that I tow behind our motorhome. Has anyone added an electric pump to circulate transmission fluid while towing? Or is this possible?
I’m not really a mechanic.
Sometimes we have an odor after towing, smells hot. I’m guessing from the transmission. On the last trip I did start the engine for a few minutes when we stopped but still had the odor when we got home. I figured someone here will know.

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[Jason B]

Shouldn't need that. Properly putting the vehicle in neutral tow puts the transfer case into neutral, not the transmission. So, there is no rotation in the transmission. If you don't follow the neutral tow procedure to a T, you'll be buying a new transmission soon.

 

[jro58]

I follow the instructions. It seems after we tow we have an odor. I was thinking it was the transmission but obviously I’m wrong, I mean if I stop and think it’s in neutral. It tows great in and out of flat tow easy. I just don’t know what I’m smelling. It’s only after towing and doesn’t last long. Thanks

 

[ScarzRanger21(2.0)]

Just doing a quick google search:

• Flat Towing Effects: The smell is often "road grime," rubber, or diesel smoke from the RV or road debris that collects in the Ranger’s undercarriage and gets sucked into the A/C system while being towed. Setting the climate control to recirculate before shutting down can help.
• Overheating Brakes/Components: If the Ranger was not properly placed in "Neutral Tow" mode or if the parking brake was partially engaged, the brake pads can overheat.
• Recommendations:
  • Check that the parking brake is completely disengaged.
  • Inspect the undercarriage for any burning debris or melted wire harnesses.
  • Verify the towing procedure, specifically that the vehicle is in Neutral and the battery is not draining, which can affect electronic parking brakes or components.
  • If the smell persists, have the transmission fluid and brake components checked for overheating.

 

[airline tech]

Awhile back another member had the same question (camping trip) and with that I dug into it and determined that the (Smell) like hot fluid or burning rubber smell was simply the (Output Sharts) on the transfer case rotating (fluid is hot and the seals are hot) the inputs shafts are physically disconnected (Interlinking the Transmission and T-Case)
So flat towing provides no internal cooling effect as well as no physical airflow across the Transmission and T-Case as if you were normal driving

 

[FatalException0E]

... the (Smell) like hot fluid or burning rubber smell was simply the (Output Sharts) on the transfer case ...

Well, if it's sharting that could certainly be a source of an unpleasant smell.

 

[Davidjc]

I follow the instructions. It seems after we tow we have an odor. I was thinking it was the transmission but obviously I’m wrong, I mean if I stop and think it’s in neutral. It tows great in and out of flat tow easy. I just don’t know what I’m smelling. It’s only after towing and doesn’t last long. Thanks

I've noticed it too.

 

[D K]

Why would it not get any airflow and why would the fluid be getting hot when the transfer case is only 'idling'?

Awhile back another member had the same question (camping trip) and with that I dug into it and determined that the (Smell) like hot fluid or burning rubber smell was simply the (Output Sharts) on the transfer case rotating (fluid is hot and the seals are hot) the inputs shafts are physically disconnected (Interlinking the Transmission and T-Case)
So flat towing provides no internal cooling effect as well as no physical airflow across the Transmission and T-Case as if you were normal driving

 

[D K]

What gear is the transmission in when you are towing?

I follow the instructions. It seems after we tow we have an odor. I was thinking it was the transmission but obviously I’m wrong, I mean if I stop and think it’s in neutral. It tows great in and out of flat tow easy. I just don’t know what I’m smelling. It’s only after towing and doesn’t last long. Thanks

 

[airline tech]

Why would it not get any airflow and why would the fluid be getting hot when the transfer case is only 'idling'?

The dead space or aerodynamic wake - behind the RV lowers the (Ram Air) effect across the engine bay.
The T-Case is in (Neutral) but the internals are still spinning along with the driveshafts

The only physical disconnect is between the Transmission & Transfer Case

So, Transmission is placed in (N), and Transfer Case is (Electronically - Sifted to) (N)
(N) is an electronically selectable position and it puts the shift lever in a detent between 4-Hi and 4-Low which is only selectable from the IPC Menu and following a strict set of instructions

The main issue with this and some owners have experienced, is the battery voltage dropping down to a point where it produces brownouts on the modules, they reset and when they reset it dumps the memory of being in (Neutral Tow) and the transfer case shifts back to 2 High thus recoupling the transmission and destroying the internals due to the internals of the transmission spinning without the pump running.
To prevent this from happening - ensure you have a good charge line between the RV and the Truck

 

[D K]

Yeah, well, like i mentioned in the other thread - this is NOT what I would be doing.

Having the trans in neutral is just plain stupid (on Ford's part).

Now, if it's some kind of a setting that you cannot engage N in the tx case unless the trans is in neutral also, then that's a different story.
If that's not the case, you want your trans to stay in park and tx case in neutral.

There are no 2 ways about it.

If you don't, you are going to transfer parasitic drag from the output shaft of the tx case to the input shaft of the tx, to the output haft of the trans and that is going to attempt to turn the clutches and shafts inside the trans.
This is NOT what you want. The smell that you are smelling is most likely thhe hydraulic fluid in the trans.

The aerodynamic 'wake' that you mentioned is so small that it is insignificant!
If you were measuring the air going to your radiator, yes, but a transfer case that is doing essentially zero work - not even close.

So, that's what I would do, but its your truck and your choice.

 

[airline tech]

In Neutral Tow:

The transfer case input shaft is not connected
The transmission output shaft is not being driven

Yes, I am in agreement on the cooling of the T-Case, so it's the only logical thing it could be and that is the (T-Case) heat rising up when towing has concluded and the only other thing which would be possible is (Hot Tire) film and road film, settling on the truck from the RV itself and when the truck is started its burning off and you will eventually note that the truck has a huge (air Inlet) door for the climate control, larger than normal vehicles that pulls outside air into the cab and even when its closed 100% electrically it is physically about 10% open.

So, since I do not flat tow, I can only assume where the smell is truly coming from and a deeper isolation test would be needed to confirm it such as hit the (T-Case) with a thermometer when you are smelling the (Hot) rubber or fluid smell that radiates after a flat tow or hitting the rotors with it (are you actually smelling) hot rotors and pads

 

[D K]

It is correct that when the transfer case is in neutral, the output shaft of the tx/drive shaft is not connected to the input shaft of the tx.
However, there is a hydraulic resistance and it does transfer SOME mechanical leverage.
When I worked at AAA, I saw 10's if not 100's of transmissions get fried that way.
When you are cruising down the freeway, the forces will transfer and eventually end up turning the output shaft of the transmission.
It is not a 1:1 ratio and there is not mechanical connection, but there definitely is forces that that transfer.
Think of a manual transmission in neutral at a stop sign, start to force the shifter into gear without the clutch and the car will start creeping forward due to the synchros.

As a totally independent exercise, I am sure we can replicate this on a lift.

Now, all of this could be null and void if there is no other way to keep the tx case in neutral other than going through the menu and following the steps.
That's not what I am talking about.
I am talking about straight up, mechanical engineering. If, give the option, you would always want the transmission in park and the transfer case in neutral.

Always. No other way.

If this is not an option, you have to find ways around it and get a work around like leaving the transmission in neutral.

I, for myself, will find another way.
I don't know what that is yet, but I will figure it out.
I just have to verify what the mechanics are that shift the tx into neutral.
Is it a spring loaded solenoid? Something else? I don't know yet. But, once I find out a reliable way to keep the tx in neutral - thats what I will do, no matter what the owner's manual says.

Again, that's me, I am not saying anyone else should do that and if they do - do it at your own risk!

In Neutral Tow:

The transfer case input shaft is not connected
The transmission output shaft is not being driven

Yes, I am in agreement on the cooling of the T-Case, so it's the only logical thing it could be and that is the (T-Case) heat rising up when towing has concluded and the only other thing which would be possible is (Hot Tire) film and road film, settling on the truck from the RV itself and when the truck is started its burning off and you will eventually note that the truck has a huge (air Inlet) door for the climate control, larger than normal vehicles that pulls outside air into the cab and even when its closed 100% electrically it is physically about 10% open.

So, since I do not flat tow, I can only assume where the smell is truly coming from and a deeper isolation test would be needed to confirm it such as hit the (T-Case) with a thermometer when you are smelling the (Hot) rubber or fluid smell that radiates after a flat tow or hitting the rotors with it (are you actually smelling) hot rotors and pads

 

[RangerBill]

It is correct that when the transfer case is in neutral, the output shaft of the tx/drive shaft is not connected to the input shaft of the tx.
However, there is a hydraulic resistance and it does transfer SOME mechanical leverage.
When I worked at AAA, I saw 10's if not 100's of transmissions get fried that way.
When you are cruising down the freeway, the forces will transfer and eventually end up turning the output shaft of the transmission.
It is not a 1:1 ratio and there is not mechanical connection, but there definitely is forces that that transfer.
Think of a manual transmission in neutral at a stop sign, start to force the shifter into gear without the clutch and the car will start creeping forward due to the synchros.

As a totally independent exercise, I am sure we can replicate this on a lift.

Now, all of this could be null and void if there is no other way to keep the tx case in neutral other than going through the menu and following the steps.
That's not what I am talking about.
I am talking about straight up, mechanical engineering. If, give the option, you would always want the transmission in park and the transfer case in neutral.

Always. No other way.

If this is not an option, you have to find ways around it and get a work around like leaving the transmission in neutral.

I, for myself, will find another way.
I don't know what that is yet, but I will figure it out.
I just have to verify what the mechanics are that shift the tx into neutral.
Is it a spring loaded solenoid? Something else? I don't know yet. But, once I find out a reliable way to keep the tx in neutral - thats what I will do, no matter what the owner's manual says.

Again, that's me, I am not saying anyone else should do that and if they do - do it at your own risk!

It's an electric motor.

 

[D K]

Thats a start, but its too vague...

What kind of electric motor.
What is the fail safe?

It's an electric motor.

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