Better to idle in Park or Neutral?

[GitEmSteveDave]

So I idle my KJ until the coolant hits 90F according to my Torque Pro app(unless it's ~80-90F ambient already, then I go a bit higher) and try not to hit over 2k RPM for at least the first two miles(by that point the engine hits 160F, which Torque says is "operating temp"). But I realize that my KJ isn't like my Diesel Dodge, which had a plug in heater, which passed some heat to the trans through conduction.

Is it better to idle in Park or Neutral to help warm up the drivetrain when the temps dip down to 30F, or does it make no difference?

 

[LibertyTC]

When it is cold out, I like to give the Jeep a better chance to warm up to 170F before driving off.
I know the the whole system is more happy & the power steering is flexible by then too.
Park or Neutral, I use neutral with park brake on sitting in it, hoping that some extra circulation is happening in the transmission then.

 

[CherokeeLiberty]

The only difference between park and neutral is whether the pawl is engaged or not. There is no difference in how the ****** will warm up.

 

[turblediesel]

Park. Then it won't roll away when you jump out for... whatever.

 

[kejobe]

I let it idle for a couple minutes only, in neutral. I don't know if these ******'s are like the 46RE's in the 2nd gen Ram I had. Those only pump fluid in neutral or drive gears, not in park. For that reason is why I choose neutral.

 

[GitEmSteveDave]

Park. Then it won't roll away when you jump out for... whatever.

That's not an issue. Where I park at home is grass with two nice ruts for my tires and some paving stones for where my front tires are so I know where to stop.

 

[tommudd]

At home never have to warm up, of course having a attached garage helps that process . First thing I look at when moving anywhere, has to have a garage. LOL

Now when out I let it warm up a bit to maybe 80-100 degrees, and away I go, never have I waited to get anything any warmer

 

[wycowboy]

Unless Mopar has changed how their transmissions pump fluid in the last few years it is better in neutral. In park the pump is not moving fluid, it only does it in neutral.

 

[GitEmSteveDave]

Unless Mopar has changed how their transmissions pump fluid in the last few years it is better in neutral. In park the pump is not moving fluid, it only does it in neutral.

Is that why you are supposed to check your fluid while it's running in neutral?

 

[Cardhu]

When its really cold like I get up here; I find the diff fluid stiffness is a far larger concern than trans fluid temp. The first km/mile is pretty slow just to make that a little more liquid like. By then i'm not concerned about trans oil temp.

Keep off your steering stops if its really cold. great way to blow a hose when the PS fluid is warming up / being froze by the cooler. And by cold i mean in the -30C and below category.