The last word on flat towing

So it’s safe to flat tow an ADD vehicle with the transfer case in Neutral, and the rear driveline disconnected?

With manual hub trucks you can simply just put them in free and the CV axles won’t spin anymore.

 

I would have to look at the gearing powerflow inside the transfer case . with the front driveshaft still connected , you Got to make sure the transfer case oil pump is pumping with the rear driveshaft removed .

 

It's my understanding now (and was in the past) that if your transfer case has a neutral, you can tow with OUT disconnecting driveshafts.

 

Entirely depends on whether or not the oil pump is driven off the input shaft or the chain/gear mechanism and where the oil pump is in that mechanism. The former does not pump while in neutral because the input shaft isn't connected to the wheels and the latter only pumps if the pump is on the output side of the equation.

 

Your driveline is still spinning something in the transfer case regardless if it’s in Neutral.

 

Ok back to this.

So we know it's safe to tow a manual trans. truck 4WD, w/ ADD behind a motorhome in 'N' and 'N'........because people have been doing it for 20 something years.


Is the transfer case different between manula and auto.?

 

Those CV axles are always spinning with a Tacoma but do not overheat or create a towing issue .
. As long as the transfer case has the N feature , you are fine .

 

So the front driveline is irrelevant when flat towing, how about the rear?

 

Everytime I visit this question (in my head) I get myself confused.

 

Wow , this is 5000 posts for me LOL
Transfer cases are the same in auto as well as manual . You need the N feature to be able to tow with both driveshafts bolted up . When you select N in the transfer case , it prevents the output shaft of the automatic transmission from dragging the forward clutch .
Personally , I wouldnt take the chance . always removed the shafts but thats just me . Is removing the shafts overkill with the N feature ? yes

 

As you see from the responses, it's somewhat variable based (on how the truck is equipped).

Personally I think you've offered the correct (for this situation) answer above.

If you offer alternatives and he messes it up, it will always be your fault.

 

Well, it's good to know your take (gearcruncher as you're the defacto trans. expert) as it's a very relevant question, even if just being towed across town so thanks.


OP...? You still there. laughs.


It was brought up to once that it's not safe NO MATTER WHAT because what if you hit a pothole and it went into gear? You would smoke EVERYTHING, engine, transmission...everything turning 20 thousand rpm if it popped into 1st.
Yea, anything's possible.

 

Your rear driveline doesn't connect to the transfer case, it goes straight to the transmission. If your front axle has hubs, hubs unlocked and your in the exact same setup as if you're driving in 2wd. All parasitic drag pretty much stops at the front diff, nothing us moving that isn't designed to do so.

With the rear shaft connected, ground turns the wheels, wheels turn the axkes, axles turn the diff. Everything up to this point is bathed in oil all the time, no issues.

But, diff turns the dshaft, and dshaft turns the tranny output. The output bearings and other bits in an auto are not bathed, they're lubed by a pump, that only pumps when the motor is running, which means your turning dry. Things spinning at high rpm HATE THAT and let you know in catastrophic ways.

A manual has more parts that are either sitting in gear oil (much thicker than tranny fluid) or are lubed by splashing. So if anything is turning, some lube is moving, but that's not every manual. Even then you want to actually drive it every couple hundred miles to get lube everywhere. People that flat tow a lot often swap rear ends to fully floating so they get locking hubs on all 4.

Tldr, pulling the rear shaft is the safest route.

 

you can tow the truck backwards just fine. Front wheels to the ground.

when you're in two wheel drive one of your front wheels simply spins the side gears and the other tire spins freely because the differential is open. Thus you will not turn the driveshaft

 

.
...^^^... Thanks for that info ...

 

I believe the only configuration that will allow 4 wheel flat tow is a manual 4x4 because the transmission is isolated when in neutral and the transfer case being in neutral isolates the drive shafts from the transmission. Automatic trans will not work because of the oil circulation needed even when in neutral.

 

So consensus is it’s okay to tow a Manual/4x4 with all four wheels on the ground if in Neutral on the transmission and the transfer case, but it’s not okay to tow an Automatic/4x4 because of the aforementioned oil pump issue?

 

That's a definitive maybe! Some manuals will be ok, others won't but the is are in the manuals favor.

 

And now it's mentioned there's a pump in the transfer case.

Oh well. Like I said everytime i visit the subject, I get confused again. I just know people do it cause I see them.

 

Does the owners manual say what towing methods are acceptable? But it may not suggest removing/disconnecting drive shafts even if it would make it safe.