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Automatic 1-2 shift problem

51K views 63 replies 23 participants last post by  PBBLASTER 
#1 ·
I have a 2016 with auto trans. It has the worst 1-2 upshift. It acts like is is slipping about 50% during the 1-2 upshift. It has taken as long as 2 seconds to complete the upshift. It acts like a CVT trans where there is no defined drop in RPM. My wife who pays no attention to vehicle behavior has even commented on the problem. Has anyone else experienced a similar problem? I am taking it to the dealership but would like to have s much information as possible before I do.
Thanks
 
#2 ·
I have the exact same issue! Mines a 2015 auto 3.73 and has done the same since new. Dealer gives free oil changes so I mentioned it at the first one, they did some computer updates that they said were due and said try it, still the same, next oil change they said the tranny fluid was low and they topped it and drove it and said it felt good but sadly this wasn't true. I'm on the verge now of emailing Chrysler and also bringing it to a different dealer and persisting more this time, I've just been busy with work. My jeep has 21000kms on it. (Canada) let me know what happens with yours, it's my first auto and I haven't been impressed like many seem to be.
 
#5 ·
I am getting ready to take my '16 JKU HR to the dealer for the very same issue.

My '15 JK Rubicon was flawless.
 
#7 ·
Since most newer automatic vehicles adapt to a persons driving style and base its shift points on the position of the throttle pedal, one of the first and easiest things to do is put the key in the run position without the engine on and slowly depress and slowly release the gas pedal then turn the key off. Then start the jeep and give it a spin. It should take anywhere from 50 to 100 miles for the computer to relearn its new shift patterns according to your driving style. Another option which some people don't recommend is doing a hard reset of the computer by disconnecting the battery for five minutes.
 
#8 ·
Following as well. The OP's description sounds like what mine does too, although for me the rpm does go down and up a little (less than 500 difference). I had dismissed it as just being different from my previous car, since I don't know much about these things. But with this thread, I am again wondering if something is abnormal. I did try shifting from 1 to 2 to 3 with the autostick yesterday (completely unrelated to this, so I wasn't paying super close attention), and it did not seem to have the same behavior. It seemed "normal". 2016 JKUS, auto trans of course. And I did try the gas pedal calibration thing early on. Maybe I should try it again.
 
#9 ·
I took it to the dealership. They told me they could not duplicate the problem. They flashed the PCM because there was an update. It did not help. If anything it got worse. I am going to install a dash cam pointed at the instrument cluster and record every shitty shift. When I get a good batch I'll edit and post to youtube.
 
#11 ·
I used a dashcam to record the tach and speedo while driving. Sorry for the bad angle but there are few options for mounting camera close enough. As you can see from the video the needle drops only 200rpm during the 1-2 upshift while driving in "D".The tach needle also tends to fluctuate while it's trying to shit. It feels like it's in a constant semi-controlled slip. The Manual mode eliminates problem. If use more throttle in "D" forcing shift point to be 3K or higher the problem is also reduced.

https://youtu.be/D0yj0Yu-DpI
 
#22 ·
Watching this video the shift seems to have less lag when you say it is a bad shift. I say it is normal, it is giving you a smoother transition into the next gear instead of jerking the jeep. My wifes BMW shifts this way, almost like there is a flatspot in the shift but it is butter smooth. I think it is jeeps way of giving a more forgiving ride.
 
#12 ·
2015 auto 3.21 gears, I have the same exact shifting behavior for gears 1, 2, and 3. Same thing whether I leave it in auto or manual shift it. There was another big thread about this issue and some people said it is normal torque converter behavior as it locks up, but others were saying it shouldn't behave like that. Please keep this thread updated if you find a solution because the other one died out. I want to know if it's normal or if my Jeep has a real tranny problem too.
 
#13 ·
I don't want to jinx myself thankfully mine is fine. I really like the NAG 1 transmission compared to the 4 speed unit it replaced. Maybe some of you guys with this problem have a low fluid level? I know a few people over the years doing under hood checks of new vehicles finding low fluid levels. I would even consider disconnecting the negative battery terminal for a few minutes and stepping on the brake before reconnecting it. Do this after the dealer told you they can't find a problem. This way you don't run the risk of clearing a hidden code possibly making diagnosis harder for them.
 
#17 ·
Has anyone ever tried to start in 2nd gear? I have a 2013 jkur auto that has the SRT 5 speed... There is a feature where I can go manual, select 2nd, and it does a soft launch for antislip snow/ice conditions in 2nd gear instead of first. I have experienced my jeep throttling differently in auto mode and assumed I just didn't come to a complete stop and it engaged that long 2nd gear or the anti slip feature on its own... Just a thought.
 
#23 ·
All NAG1s do this... using auto-stick, you can start out of the hole in 2nd and up-shift through the gears.

The other issue you describe is a characteristic of when in Drive, how the NAG1 grabs 2nd gear instead of 1st gear on low speed deceleration. This drove the SRT8 guys nuts because even with gobbs of horsepower and more throttle it wouldn't downshift to 1st gear.. and it would take time to get the rpms back for more spirited driving.

If you want 1st gear on low speed decel, you're forced to use auto-stick.

.
 
#19 · (Edited)
A better video of the problem.
You have a lot of overlap when it's in Drive but not when you use Auto-stick? Mine shifts nice and firm.. the reason I wouldn't allow the tech to install that update.

I'd make the dealer swap out the TCM.. that definitely isn't normal for a NAG1 transmission. This trans is adaptive and shifts firmer when you drive more aggressive. They do make different solenoids you can install to make it shift firmer, but I've never heard of a Wrangler with them.

Also, this trans gains more line pressure as the trans gets warmer.. as a protective measure. Check your fluid level as demarpaint suggested.. but if you're getting two completely different driving experiences in Drive vs. Auto-stick then something is probably amiss between the TCM and ECU...

Take it back to the dealer. Don't take no for an answer.

.
 
#21 ·
Assuming the fluid level is full, I have a feeling it has something to do with TC lockup. I have a feeling when you use auto stick it changes the TC lockup programming. Does driving more aggressively in D change the behavior any?

I'd bring it back and have it checked, if they insist its fine try disconnecting the negative battery terminal for a few minutes and step on the brake. Then do the gas pedal calibration after you reconnect the battery terminal and drive it a bit more aggressively. See if that helps any. I'm just thinking out loud.
 
#24 ·
I have to say overall I'm very pleased with the NAG 1 transmission. It can easily handle probably twice the torque the 3.6L can put out. I like the fact that once it's in 5th gear it stays there for the most part, and the TC isn't locking and unlocking like the 4 speed AT it replaced does.
 
#28 ·
I had a 2012 RHD with 3.73's and now a 2015 RHD with 3.21's. Both do this same 1-2 shift hesitation under certain conditions. Both jeeps do/did it at a point where there is a slight incline to the road when I am leaving a mailbox and light-footing slightly uphill trying to keep from revving too much. Its a habit I've gotten into over the years that saves me several $ per day 303 mail days a year. :) It does seem to me its a glitch that only shows up with a light-foot driving style. Neither rig did this when I get into the throttle a bit more.
 
#31 ·
This complete procedure has to be done to re-set the "adaptive" memory:

"The Electronic Control Module, or ECU as its commonly called, stores the information for your vehicle and your driving habits in its memory. The memory is maintaned by a series of capacitors that hold a charge and maintain power for the ECU when the vehicle is turned off. The following procedure will allow you to reset the memory and allow the computer to 're-learn' how to drive by adjusting to the drivers habits and the vehicles modifications".


1. Disconnect the battery by removing the positive battery cable. Remember, the positive battery cable.

2. Ground the positive cable to the negative cable for 30 seconds to erase the electric charge in the capacitors.

3. Reconnect the positive cable to the battery.

4. Turn the key to on but do not start.

5. Turn the headlights on.

6. Turn the headlights off.

7. Turn the key off.

The ECU has now been reset to its factory settings. For the next 50 warm-up periods the ECU will re-learn the engine and driving habits for your driving conditions and the newly installed parts.
 
#34 ·
I wonder if the problem is the driver is backing off the throttle slightly as the transmission is shifting? That would cause a flair like we see in the video. Some people who go from a stick to automatic transmission can subconsciously do this at times. Also if you drive very easy on the gas can cause it. I would try driving a little more aggressively and making sure not to back off the gas before or as the transmission shifts.

With a little playing around it is possible to get a flair between shifts.
 
#37 ·
Shift Problem Eliminated

I took it back to the dealership and had the shop foreman ride with me. At first he did not notice the problem then I had him drive it and he was able to experience it. Long story short he said It was normal and since there were not fault codes there was nothing he could do. He said bring it back when it throws a CEL or in 6 months in case there was a new TCM flash.

I wasn't able to just sit back and wait for the engineers at Jeep to get off their ass and correct the problem. I don't care what anyone says the problem was not normal and not acceptable. It was not how I used the throttle or adaptive memory at fault. I am sure a proper TCM program could have done some good but who knows when or if that would happen. I have rebuilt quite a few transmissions when I was a Dodge -Jeep technician so I know how they should work and I cannot tolerate one that acts up.

Thanks for the lead on the shift kit ms998dna. It was well worth the risk and worked perfectly. There is no slip into 2nd and all the shifts are more crisp. It shifts how and automatic should. It’s amazing to me that it takes and aftermarket transmission engineer to fix well-known OEM transmission problems. Apparently TRANSGO has shift kits to correct common issues for all transmissions. These are not meant for racing, just to restore proper operation. I plan to put one in a friends Camry to resolve a TCC engagement issue.

If you are of tired of a driving a slushbox one of these kits may the answer for you too. I can provide a couple helpful installation tips if anyone is interested.
 

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#38 ·
I took it back to the dealership and had the shop foreman ride with me. At first he did not notice the problem then I had him drive it and he was able to experience it. Long story short he said It was normal and since there were not fault codes there was nothing he could do. He said bring it back when it throws a CEL or in 6 months in case there was a new TCM flash.

I wasn't able to just sit back and wait for the engineers at Jeep to get off their ass and correct the problem. I don't care what anyone says the problem was not normal and not acceptable. It was not how I used the throttle or adaptive memory at fault. I am sure a proper TCM program could have done some good but who knows when or if that would happen. I have rebuilt quite a few transmissions when I was a Dodge -Jeep technician so I know how they should work and I cannot tolerate one that acts up.

Thanks for the lead on the shift kit ms998dna. It was well worth the risk and worked perfectly. There is no slip into 2nd and all the shifts are more crisp. It shifts how and automatic should. It’s amazing to me that it takes and aftermarket transmission engineer to fix well-known OEM transmission problems. Apparently TRANSGO has shift kits to correct common issues for all transmissions. These are not meant for racing, just to restore proper operation. I plan to put one in a friends Camry to resolve a TCC engagement issue.

If you are of tired of a driving a slushbox one of these kits may the answer for you too. I can provide a couple helpful installation tips if anyone is interested.
I'd be interested in a how to, and how long the job took you. How much skill is in involved and if the parts just drop in or if you have to do some drilling, etc? How does it impact normal downshifts when slowing down or slowing to a stop? Thnks.

Forgot: How hard to drop the pan, anything in the way?
 
#41 ·
I would also be interested in any tips you have for installation of this kit.
Although I have not messed with the NAG1 transmission, I have some experience with installing shift kits (Sonnax Accumulator Valve and Tricumulator Springs) in Fords 4R100 in 7.3L Powerstrokes.
 
#44 ·
Answers to common questions:

I have not noticed any change in downshift feel or behavior.
There was no drilling or machining required.
The risk is low as long as you follow the instructions, refer to manual and keep everything clean.
You can always keep the original parts and swap them back in case of warranty transmission problems.
The kit took me about 4 hours because of the prep work (siphon and cleaning). If you don’t mind getting covered in trans fluid, it could be done faster. Another set of hands would be helpful but not required.


I am working on the helpful installation tips now. I was working alone when I installed this kit so I did not fell like trying to video everything. I will leverage existing videos and resources for the instructions.
 
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