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-   -   What to expect at -16 (-55 windchill) (http://www.jeepgarage.org/f73/what-to-expect-at-16-55-windchill-70082.html)

wasupdu 01-06-2014 09:28 PM

What to expect at -16 (-55 windchill)
 
I can't remember the last time it's been this cold outside, but I've noticed very irregular shifts the last couple days when it's been well below zero (with the vehicle fully warmed up for over an hour).

Example - I couldn't get my '14 v6 Summit to shift out of 6th gear (automatically) while going 70+ mph down a hill. Is this the weather or should I be alarmed?

xJoshxx 01-06-2014 09:45 PM

Re: What to expect at -16 (-55 windchill)
 
Quote:

Originally Posted by wasupdu (Post 955875)
I can't remember the last time it's been this cold outside, but I've noticed very irregular shifts the last couple days when it's been well below zero (with the vehicle fully warmed up for over an hour).

Example - I couldn't get my '14 v6 Summit to shift out of 6th gear (automatically) while going 70+ mph down a hill. Is this the weather or should I be alarmed?

Correct the zf is very particular on it's Fluid temp. my WJ was the same way if it's to cold it won't shift up.

the ZF 8 speed actually has a heater built into it also! to help keep the fluid at 170-180F

TonyMontana 01-06-2014 10:07 PM

No issues with my V8 8-speed ZF in temps down to -35deg cel. It may have to due with the V6 8-speed being a Chrysler built unit licensed from ZF whereas the V8's is built by ZF and is pretty much identical to the ZF 8-speeds found in Audi, Bentley and BMW high torque applications - Chrysler just provides it's own software calibration.

jbjones85 01-06-2014 10:41 PM

Re: What to expect at -16 (-55 windchill)
 
my very first shift from 1 to 2 in the mornings is a little rough, other than that it behaves as normal. (note haven't seen anything lower than 15F)

loveracing1988 01-07-2014 01:34 AM

Quote:

Originally Posted by wasupdu (Post 955875)
I can't remember the last time it's been this cold outside, but I've noticed very irregular shifts the last couple days when it's been well below zero (with the vehicle fully warmed up for over an hour).

Example - I couldn't get my '14 v6 Summit to shift out of 6th gear (automatically) while going 70+ mph down a hill. Is this the weather or should I be alarmed?

Do you have the latest software? There were supposed to be fixes for the cold shifting performance in that along with other improvements.

amr40509 01-07-2014 07:04 AM

Re: What to expect at -16 (-55 windchill)
 
It was -9f here this morning when I loaded up for the drive to the office (Jeep was not in garage and had been parked outside for 12+ hrs).

I have the diesel - I noticed that it did hold 7th gear for awhile (maybe 1 min at 65mph) before it hit 8th. Normally it cruises that speed in 8th and never kicks down.

I know my old Nissan with 5speed automatic wouldn't hit overdrive until it got to normal operating temp (even said so in the manual), I wonder if this is some sort of quick warmup feature they have.

SnoFire 01-07-2014 06:10 PM

Re: What to expect at -16 (-55 windchill)
 
-22 this morning before the windchill factored in (-45 or so with it). Mine also holds 7th gear on the highway but once it warms up it is fine. Gears 1-2 have always been a little rough so I'm not concerned about it (Jeep is going in on Friday to get the updates and oil changed).

mswlogo 01-07-2014 06:21 PM

Re: What to expect at -16 (-55 windchill)
 
Quote:

Originally Posted by SnoFire (Post 956339)
-22 this morning before the windchill factored in (-45 or so with it). Mine also holds 7th gear on the highway but once it warms up it is fine. Gears 1-2 have always been a little rough so I'm not concerned about it (Jeep is going in on Friday to get the updates and oil changed).

Mine was staying in 6th and 7th when it was 0 F out after an hour of highway driving.

If I recall correctly the Transmission was to only 150 or so.

I wonder sometimes if the Towing Transmission Cooler keeps my transmission too cool when it's frigid out.

Since the new Rev C update I did try a short highway trip and transmission I think was only 140 and it shifted into 7th and 8th fine. But that was not a full test. I'd have to make the same trip at the same temp to be 100% sure it's "fixed".

If you are having Cold Shift problems get the Rev C or greater update on the V6 Transmission. It specifically states improved cold shifting.

Prestone 01-07-2014 06:29 PM

Last few days it's been between - 30 to - 40. My car sits outside, everytime I get in my car my brake pads freeze to the rotor. Makes a horrible pop sound when I first take off. Anyone else experience this?

loveracing1988 01-07-2014 06:57 PM

Quote:

Originally Posted by Prestone (Post 956346)
Last few days it's been between - 30 to - 40. My car sits outside, everytime I get in my car my brake pads freeze to the rotor. Makes a horrible pop sound when I first take off. Anyone else experience this?

Only when I drive through deep snow and then immediately park.

Krisw123 01-13-2014 09:23 PM

Quote:

Originally Posted by Prestone (Post 956346)
Last few days it's been between - 30 to - 40. My car sits outside, everytime I get in my car my brake pads freeze to the rotor. Makes a horrible pop sound when I first take off. Anyone else experience this?

Try leaving parking brake off. Unless it's on a steep hill of course!

comnjeep 01-13-2014 10:53 PM

Re: What to expect at -16 (-55 windchill)
 
Cold weather makes more drag on a car for many reasons including denser air.. So seems normal. I would think "cold shifting" means it is not up to operating temp, not ambient temp per se... but that could be at steady state in cold I suppose. What does your ATF temp read?

I often drive my cars in a higher gear in extreme cold. MPG is already suffering so why not run the fluid temps at closer to ideal?


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