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Vibration between 35 & 40 mph


Trains123

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Common complaint among many DJ owners.

My personal experience (based on my DJ) is that

it shifts into 6th gear at about 63 km/h or around 40 mph

for fuel economy and if you accelerate slowly without

either double tapping or a solid push of the gas pedal

it will lug the engine to achieve the speed you want.

I use manual mode sometimes in the city and run around

in 4th gear in traffic where our limits are 60 km/h / 40 mph.

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Mine does the same ('13 R/T AWD). My dealership explained that it was the AWD releasing the transfer box and going to FWD mode. Does it just as I cross the 40 mph threshold, both accelerating through it and when I slow down (though not as noticeable on deceleration, it is there, on mine anyway). Since it has been going on since day 1 and hasn't changed one iota (not longer, not shorter, nor at any other different speeds or conditions) I'm inclined to buy their explanation for the time being. Doesn't affect the car any, but, it is like running on a rumble strip for a second - that's about all the time it takes. Has to do with higher fuel efficiency since AWD is rarely needed at speeds above 40 mph the transfer case disonnects the rear differential going to FWD mode (the car will return to AWD though if it senses wheel spin at higher speeds) and the FWD is supposed to be easier on the gas than if it stayed in AWD at all speeds.

That is the way it was explained to me and I've got no problems with their explanation to date and I've got almost 14,000 miles on the car now. I even vaguely remember reading somewhere that the AWD is actually FWD at highway speeds when the car doesn't need the AWD for stability or acceleration. When I was shopping for the DJ is when I first noticed it. Maybe one of the Dodge Cares group can shed some "technical" light on it.

Here's an excerpt from a review on the BorgWarner system:

"The ITM 3e system exercises sophisticated controls and algorithms to sense slip, converting the front-wheel-drive-based platform to all-wheel drive within milliseconds. By optimally using grip at both front and rear wheels, the system also augments vehicle handling and traction. At highway speeds, it automatically reduces power transfer to the rear wheels, which improves fuel economy versus other all-wheel drive systems. In addition, the ITM 3e system is designed to work in cooperation with other vehicle systems like anti-lock brakes and electronic stability programs to further enhance traction and stability."

Edited to add exerpt from review of the BorgWarner ITM 3e AWD system.

Edited by webslave
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