[mysticalice]

Sorry for all the threads, but I'm new here, and trying to get all the 'quirks' of my car figured out (or at least get a better understanding of them).

I'm very happy with my 300C, but the shift times are ridiculously bad. And I don't mean when the engine/transmission are cold either. On the highway, at 65mph, if I floor it, it may take 2-4 seconds before it downshifts once or twice. Of course it's very seldom I need quick acceleration response, but just a little frustrating. I find more often than not I'm giving it more gas than I need to, just because I'm not sure how the transmission's going to react once it finally downshifts.

This is a 2014 model with the 8 speed 6 cylinder.

Wondering if anyone else has noticed this, and if so, if they've tried a tune to improve shift response?

 

[thrifty]

Drop it in low... I've had a 5 speed 6cyl and now an 8 speed... The auto stick was nice on the 5 but the low setting on the 8 feels like it has more pull... But you can also pick up a tuner and from what I understand it will let you get rid of the gap in response when you hit the pedal....

 

[mysticalice]

OK great, thanks, that's good information.
I'd like to get rid of it without having to shift into "L" every time I want fast acceleration (which to my understanding just drops the transmission down a gear, right? Meaning it's safe to use at any speed and at any gear?). I have no problem with a car taking a second to downshift when I floor it, but it seems this car takes SEVERAL seconds

 

[thrifty]

here ya go.....

 

[MADDOG]

I would suggest you modify your profile and add your year & model car. That will help us provide answers to your questions without you having to repeat that information if any thread or post you create with a question regarding your car.

 

[mysticalice]

Good call Maddog - thanks; updating it now

 

[MADDOG]

Thanks. That will help us all a lot.

 

[Cool_V_300C]

How long have you had the car? Maybe the system is still "learning" your driving patterns.

 

[mysticalice]

About 5-6 months and 7,000 miles

 

[mysticalice]

The driving patterns thing I can understand for regular shifts (perhaps the first few hundred miles), but generally flooring any car should cause it to give full acceleration as soon as possible

 

[Cool_V_300C]

You've definitely had the car long enough. I don't have an explanation as I also have the v6 and acceleration happens rather quickly and I don't really have to floor it.

 

[mysticalice]

Well I guess i'll have the dealership take a look at that too then

 

[Terrible Juan]

I want the OP to know he is not alone. The downshifting lag time with my 8 speed is ridiculous. I'm almost tempted to buy one of those tuners just to fix the problem.

 

[ChryslerCares]

There is a recent TSB that may help some of the shift quality issues some members are experiencing.

TSB: 21-012-14

This bulletin involves performing a subjective shift quality rating when customers experience poor shift quality and if necessary, performing the transmission adaptation learn procedure. In addition, this bulletin involves performing transmission adaptation learn procedure when the transmission is repaired/replaced and/or the valve body/TCU assembly (mechatronic) is replaced, or when the adaptation memory cells are cleared with the wiTECH diagnostic scan tool.

MODELS:
2013 - 2014 DS Ram 1500 Pickup
2012 -2014 LD Charger
2012 -2014 LX 300C
2014 WD Durango
2014 WK Grand Cherokee

NOTE: This bulletin applies to vehicles equipped with the 845RE (Sales Codes DFL), 8HP45 (Sales Codes DFG), or the 8HP70 8-Speed Automatic Transmission (Sales Codes DFD).

SYMPTOM/CONDITION:
Customers may indicate that their transmission shift quality does not meet their expectations.

Perform the “EIGHT SPEED TRANSMISSION SHIFT QUALITY DIAGNOSIS” if a customer indicates that their shift quality does not meet their expectations.

DISCUSSION:
The 845RE, 8HP45, or the 8HP70 8-Speed Automatic Transmission uses a sophisticated shift algorithm that includes learned information so that the shift quality remains excellent even as the transmission wears. This learned information is recorded in memory cells referred to “Adaptation Memory Cells”. Each applied clutch records the amount of time it takes to fill the clutch (Fast Filling Counter/Filling Time) and the amount of pressure (Filling Counter/Filling Pressure). The adaptation memory cells are set to zero (0) on every new transmission (new in vehicle and/or replaced for service) and when the transmission control module is replaced for service. In addition, the adaptation memory cells are set to zero (0) when the transmission control module adaptation memory cells are cleared using the wiTECH diagnostic scan tool. Until the adaptation has been learned/relearned, the transmission shift quality may not meet the customers expectations.

If the adaptation memory cell “counter” is zero (0), than the adaptation memory cell has not been updated. The, Filling counter ideally should be at least 12 (6 on 8HP70/90) and Fast Filling counter at least 4 (2 on 8HP70/90) to improve shift quality and with each subsequent count, shift quality will improve even more.

Hope this info is helpful to some members.

 

[Smokey613]

The downshifting on mine pretty much sucks. I have just learned to live with it. There is always a lag/delay when cruising and then dropping the hammer on it. It is just the nature of the regular 300, not sure how the SRTs work. Chrysler wants the car to be "civilized" and provide the power "smoothly". The problem is, when I punch it I want that trans to downshift and let that Hemi power hit quickly, not like some grandma ride.

 

[mackguy]

I'm sure it also has something to do with fuel economy... low RPM acceleration is preferable if the engine has the power to do it. That's what my v8 feels like... "I think I can, I think I can... nope, lets go WOT 2nd gear!" That's what the autostick thingy is for, though I understand the C V6 doesn't get that.

Actually the 300C is probably the best car I've had from this perspective with the 394lbft it does OK. My STS that had a wimpy 315 would bog down for a little then have a crazy rough crash into some lower gear.. Mazda CX-9 does the same thing, and it annoys the heck out of my wife (when I drive) because I'm just trying to merge onto the highway and all of a sudden it slams down 3 gears and winds out (not as soon as I hit the pedal... it sort lugs for a few sec then WHAM).

 

[thrifty]

My 8speed has been giving me a downshift thump when it goes back into first.. I'm thinking that it's learned that I drive a bit quicker more then half the time.. It's just when I want to old man it the trans thinks I'm still youngin it....

 

[mysticalice]

I'm surprised with all the positive reviews on this transmission posted in this thread. I'll be honest - of all the cars I've owned (arguably most of them 400+HP, but quite a few 4 and 6 cylinder automatics) this has to be the worst transmission I've ever experienced. C'mon guys - don't be afraid to criticize an aspect of your car. you're not going to be considered a traitor to your car or the Chrysler brand by admitting that taking 3 seconds to feel any acceleration when you have the pedal floored at 50mph is horrible.

What's scary is when you actually NEED fast acceleration, 9 times out of 10 it's not when you're taking off from a stop sign... it's when you're cruising on the highway and need to get out of the way of someone that's changing lanes into you.

 

[TheKrell]

I haven't even gotten into criticizing my transmission because my pentastar engine has never run smoothly 100% of the time since I drove it off the lot. Nevertheless, I have an observation for you.

The dealer replaced the 1-3-5 cylinder head, and after a 1-day abysmal transient, the engine has smoothed out considerably. And after that happened, the transmission smoothed out too. I'm suspicious that the transmission was shifting, expecting a certain performance out of the engine. When that didn't happen, the shifts were terrible.

Now as for the lag, perhaps it's your engine. My engine problem nowadays usually starts like this. I press on the accelerator pedal expecting a little acceleration, and nothing happens. I press more, and still nothing. Finally, when I press the pedal enough, the transmission downshifts and the engine sputters and I get jerky acceleration. This usually doesn't happen, though. Usually it's very responsive and smooth. My dealer cannot reproduce the problem. The frequency and severity change with every tank of gas.

 

[GTS300C]

My 8speed has been giving me a downshift thump when it goes back into first.. I'm thinking that it's learned that I drive a bit quicker more then half the time.. It's just when I want to old man it the trans thinks I'm still youngin it....

I have the same problem with my 8 speed. And also dislike the extra pedal effort it takes to get the car moving faster at any speed. 19K miles. Off to the dealer on the 27th.