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-   -   transmission not up-shifting while driving downhill (http://www.jeepgarage.org/f107/transmission-not-up-shifting-while-driving-downhill-67434.html)

justice37 11-01-2013 08:54 PM

transmission not up-shifting while driving downhill
 
Quick question....

When I drive a downhill (rather steep) without pressing gas or brake...
a vehicle getting speed and a transmission should take up-shifting.
I am not sure all vehicle runs this way, but, at least, my previous vehicles did.

However, my new GC 14' 4x4 does not shift to upper gear.
So, when I drive downhill, the transmission is not shifting to upper gear, thus engine's rpm keeps going up unless I press gas pedal. It is noticeable when gear is low (2 or 3) I do not want to press gas on downhill.

Is GC intentionally engineered in this way? or just malfunction?

Cheddy 11-01-2013 11:07 PM

My 14 Summit does the same thing. I don't mind it, as I can lay off the brake....but I do think it is Engineered this way. If you want it to up-shift use your paddle shifter instead of the gas pedal. But no worries, seems to be normal. Had a Honda that operated the same way.

ExcursionDiesel 11-01-2013 11:45 PM

Its a brake saving feature. Downhill breaking, especially long hills, creates excessive break heating and wear.

If the transmission upshifted you would speed up from reduced engine breaking. If you press the gas to upshift, you would speed up also.

So the question is, do you want to speed up? If you do, press the gas. If you don't, let the engine and transmission help maintain a lower speed. Revving the engine is not wasting gas since the throttle is closed. I suspect it will upshift if RPMs are high enough. Use the brakes to control this on steep grades.

This behavior is desirable once you get used to it. My Super Duty Ford operates this way.


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