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-   -   issues with 8spd hemi (http://www.jeepgarage.org/f107/issues-with-8spd-hemi-67002.html)

summitdrew91 10-22-2013 03:38 PM

issues with 8spd hemi
 
First off I want to say how much I love this thing but I am having issues with the transmission. When running stop and go if you let off the gas for a second it downshifts and when you get back on the gas it lurches and isn't smooth. Seems worse under 30 mph. The dealer says it is normal but I have a hard time believing a high dollar zf trans would do this. Any input or suggestions?....

willjeep 10-22-2013 04:04 PM

Re: issues with 8spd hemi
 
how many miles? mine is getting better an better. Was never very.

lstowell 10-22-2013 04:13 PM

Re: issues with 8spd hemi
 
Quote:

Originally Posted by summitdrew91 (Post 915331)
First off I want to say how much I love this thing but I am having issues with the transmission. When running stop and go if you let off the gas for a second it downshifts and when you get back on the gas it lurches and isn't smooth. Seems worse under 30 mph. The dealer says it is normal but I have a hard time believing a high dollar zf trans would do this. Any input or suggestions?....

The high dollar ZF is controlled by the jeep software.

Will assume you are using ECO mode, not sport.

Will also assume possibly you just got it and it hasn't trained itself in yet, although you might want to consider removing a battery cable and let it set for a couple minutes and put it back. Mine [May build] was a tad jerky until this was done.


Particularly under 30 you may be triggering several modes
If you get on the gas fast and let off, it will hold the current gear and you'll get noticeable engine braking.

In ECO mode, it sort of seems to stop and think about it when you hit the gas very much. It seems to move out just as fast if you just add a bit of throttle until its moving then apply just a bit more. [Or, you could engine brake and run the revs up at the lights]

You might want to try the sport mode or the paddle shifters. Sport mode holds gears longer and gets you more acquainted with the local gas stations, but is entertaining.

If you do the battery pull power reset, it seems to try to learn a bit better, although it may still take a thousand miles or so before it more or less settles in to where you can try guessing whether it is using dog clutches for that gear or not.

Willx 10-22-2013 04:25 PM

Re: issues with 8spd hemi
 
Quote:

Originally Posted by summitdrew91 (Post 915331)
First off I want to say how much I love this thing but I am having issues with the transmission. When running stop and go if you let off the gas for a second it downshifts and when you get back on the gas it lurches and isn't smooth. Seems worse under 30 mph. The dealer says it is normal but I have a hard time believing a high dollar zf trans would do this. Any input or suggestions?....

Easy comparison to see if what you are feeling is truely normal, try another V8 Jeep and or go for a Test Drive in a X5 (Same 8 speed exactly).

bill_de 10-22-2013 04:32 PM

Re: issues with 8spd hemi
 
I had that feeling a few times back when I first got the Jeep. That was probably during the first 500 miles. As WillJeep said, it got better and better. When I drive it now I don't give the tranny a second thought.

Of course if you drive in sport mode ... then it is probably normal.
Also, when I have to drive under 30 for any distance I turn eco off. Fifth gear at 25 mph just doesn't cut it.


---

summitdrew91 10-22-2013 07:17 PM

I won't use eco mode. I have a magna flow and it sounds like a swarm of bees. It has 8500 on it. I have disconnected the battery twice and after 100 miles it comes back. I have asked it it's a software issue and get told there is nothing wrong with it. Guess I need a different dealer.

Peter_K 10-22-2013 07:22 PM

Quote:

Originally Posted by summitdrew91 (Post 915440)
I won't use eco mode. I have a magna flow and it sounds like a swarm of bees. It has 8500 on it. I have disconnected the battery twice and after 100 miles it comes back. I have asked it it's a software issue and get told there is nothing wrong with it. Guess I need a different dealer.

If this is a 5.7 Hemi, some aftermarket exhausts will sound like that when the MDS system is engaged and the engine is effectively a 4-cylinder. The exhaust pulses change and you get a different resonance. ECO mode tends to get you into MDS activation easier.

Peter_K 10-22-2013 07:25 PM

Quote:

Originally Posted by summitdrew91 (Post 915331)
First off I want to say how much I love this thing but I am having issues with the transmission. When running stop and go if you let off the gas for a second it downshifts and when you get back on the gas it lurches and isn't smooth. Seems worse under 30 mph. The dealer says it is normal but I have a hard time believing a high dollar zf trans would do this. Any input or suggestions?....

It gets MUCH better as you drive it. Mine was like you describe in the first 100-150 miles and has slowly been getting smoother and smoother. I'm at 250 now and it's almost perfect. Another person I know had similar concerns and by 500 miles on his the transmission was damn near flawless.

2014RedHemiGC 10-22-2013 08:22 PM

Re: issues with 8spd hemi
 
Also, I think the torque converter is programmed to lock up earlier at lower speeds to help fuel economy, which can feel "jerky" at these speeds.


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