Transmission Issues - slipping, slamming, mis-shifting

Forum for Infiniti M37, M56 M35h Hybrid and Q70 owners.
EdBwoy
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I have seen mention of transmission issues from some owners. My suspicion is that the issues are more than beyond the behavior of the 7 speed wanting to constantly hunt for gears.

I know there was a TSB/reprogram of the TCM that can help level things out. Not forgetting a hard reset which ends up relearn of the modules.

I suspect some correlation and would like to dive deeper into my theories. Your participation will be appreciated:
1. Do you feel like your transmission behaves funny, especially in city driving?
2. What year is your car?
3. Is it a V8 or V6?
4. RWD or AWD?
5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?
6. What solutions have you tried so far, and did it improve?


Brian35XR
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Yes among the countless reports you can find on other infiniti and g37 forums I feel like my transmission has some rough behaviors for a smooth transmission.

1. Definitely behaves funny in city driving. my biggest complaint is a hard "clunk" downshift at random in city driving. Also the car seems to have a habit of upshifting right when i press the gas hard leaving me with no power.

2. 2011
3. V6
4. AWD
5. Third owner. Always behaved like this.

6. I've tried a ECU reset which I don't feel like improves much. My friend has a G37Xs and actually had the transmission re-programmed at the dealer to the newest update per the TSB which he said made it felt like a brand new car. After a while, he complained the car was re-learning it's old bad habits. I did the ECU reset to his car and he said it fixed it again. The dealer probably just did the same for all he knows..

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cliffyk
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I just today noticed a couple of hard downshifts during a quicker than normal slow-down/stop in traffic. I was traveling 35 mph or so and had to slow/stop somewhat rapidly, just after accelerating from a light. In Sport Mode, 107k miles on the car, tranny juice changed at 103k. I believe the the reprogramming had been performed by the PO. I reset the learned behaviour at 104k or so. I think my "hurry up", now "slow/stop" maneuver may have confused the transmission control module--not overly concerned at this point.

mazz
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2013 v6 awd fortunately i have not experienced transmission issues at all

ArmedAviator
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Car: 2012 M37x
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1. Funny? No. Less than ideal shifting schedule? Yes.
2. 2012
3. V6
4. AWD
5. No, second owner.
6. If I intend on taking a corner quick and applying gas in the turn, I downshift manually into the gear I want to accelerate with using paddle shifters or shift knob and then there's no go hunting issues.


With that said, if you understand how an automatic transmission works, you may find these issues aren't really issues - it's just the nature of the beast. Sure, on occasion I get a "hard" shift where it feels like it slams into gear. This is caused by the ECU deciding to shift, deciding the line pressure needed for a smooth-ish shift (how fast it will apply the clutches), and then as it commences the shift, you change the throttle (generally lifting off). When load is high, the transmission will use more line pressure to apply the clutches more quickly so there is less clutch wear and also still maintain a smooth and quick shift. When load is low, the line pressure is low, so the clutches engage more slowly, since the clutches won't slip too much so it will be a smooth shift.

When at a high load (accelerating, for example), the ECU commands high line pressure, then just as it shifts, you let off the gas. Boom, you have no load on the engine/trans, and it is shifting with high line pressure. This is when you get the SLAM into gear.

This is true of all automatics, as far as I am aware.

EdBwoy
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Car #1.
1. 2011
2. V8, M56 sport
3. RWD
4. 2nd owner
5. Has always driven smoothly, no hiccups to speak of.

Car #2, the test mule
1. Has a weirdly shifting trans that some have described to me as "feeling like it's being held back"
2. 2011
3. V8, M56x
4. All wheel drive
5. 3rd owner, it drove like this from the first day I got it with approx 145,000 miles.
6. Based on discussions here, I thought it was something more localized to the V8s and related to the timing chain recall. So I had the dealer check my fluid levels and perform the software update. The improvement was minimal. I did a TCM relearn at home and there was greater improvement in the way it drove. It is still horrible compared to my other M56, so I gave it to an "independent driver for an unbiased opinion" and she also pointed out that it shifted funny in town.

These are 2 of the discussions that pointed me towards fluid level:
- p0420-catalytic-repair-m56x-now-missing ... 23433.html
- post6791092.html#p6788496

It seems it's not isolated to only V8s then. Good. We'll see what Q70 owners have to share

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pedsemdoc
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1. Not in automatic mode, sometimes I get a little bucking when in manumatic mode in 1st/2nd
2. 2013
3. V6
4. RWD
5. 2nd owner - think it's behaved like this as far as I can remember
6. Haven't tried anything


I think other relevant info might include

7. Mileage
8. Has your transmission ever been serviced? when/mileage? and full flush?/drain and fill?

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pedsemdoc
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7. 84k
8. Tranmission flushed by dealer at 67557, over 2 yrs ago

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paranoidjack
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1. Do you feel like your transmission behaves funny, especially in city driving?
----transmission is generally indecisive, from 40% throttle to 75% throttle it gets confused based upon travel speed.
2. What year is your car?
---2012 M56S
3. Is it a V8 or V6?
---V8
4. RWD or AWD?
---RWD
5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?
---Bought at 13k. Always been the same. TCU update relearn helped a LITTLE bit...but got "bad" again over time. (not that bad).
6. What solutions have you tried so far, and did it improve?
---None
7. Mileage now 30k.

Personally, I find the transmission works well for aggressive driving. Especially in manual mode. But when driving gently, it gets confused, overshifts, and BY FAR the most annoying...drives me INSANE....is when in manual mode, when the car comes to a stop and shifts into first gear, it's ALWAYS a hard shift. Uncomfortable. People ask "Is it OK?" I've actually had to adjust my driving and put it in D when I know I am coming to a stop, and then accelerate back out in Manual mode. It's annoying AF, but I've gotten used to it, and it's part of my driving now.

As far as really hard and problematic shifts, I've only experienced it twice...and both times it was when paddle shifting, but ALSO keeping it in "D" mode. I would recommend to anyone with these cars if you want to shift manually, put it in Manual, because if you happen to paddle shift at "that moment" when Drive is doing it's own shift, you might surprise yourself with an uncomfortably hard hit.

I'm thinking about doing a level 10 tranny like Russ did (with the TT M56). He said it increased driveability. Also, supposedly, though I am UpRev tuned, now HP Tuners will support some of our M56's....and they DO allow for Transmission tuning also....????

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Mickey917
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Sorry this is an old post but…

1. Do you feel like your transmission behaves funny, especially in city driving?

Transmission is working perfectly, except with 4 to 5 gear change that makes a little flare in automatic (about 250/500 rpm). It happens only when I drive it with few pressure on the gas pedal. When you hit hard it shift with no flare/slipping on that gear. In manual it is less noticeable (mostly not noticeable).

2. What year is your car?

2012

3. Is it a V8 or V6?

V6 Hybrid : I think that is why my post is important. I read a lot about people saying it may be the torque converter lock up doing the flare/slipping. Note that there is no torque converter on the M35h and that is the same issue that other people are facing !

4. RWD or AWD

RWD

5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?

2nd owner. Always drive like this but as it is not very annoying it did not catch your attention every day.

6. What solutions have you tried so far, and did it improve?

Ecu reset procedure. It did nothing.
I also had a recall for the transmission/hybrid module update but it changed nothing (that is a 2016 recall applied in 2021 so I know it will do nothing on that point…)

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Mickey917
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Hello, I've been searching a lot for this flare issue. Please, can someone bring his knowledge about this... This guy had the flare issue and it happens that solénoids where shots. They also find a lot of metal in the transmission oil. Plus I don't find any tsb related to the flare for the M (there is for the g).

Post #22 of this thread https://www.myg37.com/forums/engine-dri ... ted-2.html

"The service rep said that the solenoids in the original were completely shot and that the transmission fluid was littered with metal shavings. Needless to say, I am glad I stayed persistent with the dealer about the issues I was having."

Thank you very much.

madmanpauly
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Hey Ed, thanks for taking this on!

I've had the problem off and on. It was always nervous - hunting for gears but when I got it back from the timing chain replacement (the big recall event), it was extremely jerky, it felt like it slammed into gears and generally worked terribly. I didn't make it home before turning around and dropping it back off. They reflashed it and changed the oil / filter and it was back to it's "normal" nervous feel. I've gotten into the habit of dropping it into manual shift mode and using the paddles when I need to get out of a situation or just passing / merging in traffic. However, this didn't fix it long term. While I was having issues with the battery and the starter, if the system didn't get enough "juice" the tranny would behave badly again. I would turn it off and turn it back on and the issue would go away. I figured it was a file transfer or boot up issue. Happy to try stuff if you have any solutions.


1. Do you feel like your transmission behaves funny, especially in city driving?
- Yes, I leave it in sport mode and use manual for immediate shifting needs (I like to drive like I stole it)

2. What year is your car?
- 2011 M56S

3. Is it a V8 or V6?
- V8

4. RWD or AWD?
- RWD

5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?
- I'm the second owner, purchased in 2014 at 34k miles (currently at 98K)

6. What solutions have you tried so far, and did it improve?
- Reset ECU (remove battery for 30 minutes), drive in manual, replace oil / filter from dealership, charge battery, and the old "turn it off and turn it back on" maneuver.

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ibc
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Mine shifts perfectly on highways and when slowing down in most city traffic. But in STD or ECO mode, it is slow (ie, delays, hesitates) to react when speeding up in city traffic and especially when moving away from a dead stop. After a few second delay, it shifts smoothly and speeds up well. In SPORT mode, it reacts much faster but not exactly as instantly as I'd like.

Q1. Yes, Its hesitation to increase speed instantly is mildly annoying.
Q2. 2011
Q3. V8
Q4. AWD
Q5. No. But it behaved this way since we got it at 20K miles, and now it has 50K.
Q6. Reset ECU. No difference.

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ibc
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Here's an amazing coincidence (?)...

My transmission shifting issue is gone! Why?!? The car shifts beautifully now. Yay!
My only explanation is that the following did the trick:

I disconnected the battery for 8 hrs while replacing my M56 starter motor last week. Afterward, per Service Manual instructions on page EM-192, (in as-written order) I first performed the "Throttle Valve Closed Position Learning" (EC-695), and then I performed the Idle Air Volume Learning" (EC-696) without Consult-III. The Idle Air procedure steps require performing the "Accelerator Pedal Released Position Learning" (EC-694) and then it said to redo (?!) the "Throttle Valve Closed Position Learning" (EC-695) again. So I did.

After all that, my test drive was magical. No TX shifting problems now. Awesome.
So it was a software needing re-initialization problem all along? Weird.

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Mickey917
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Thank you for this tip, I will try as soon as possible. Even though we haven't the same issue.

EdBwoy
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Sorry folks, I didn't mean to abandon this post. Somehow it just flew under the radar.

Looking at the timeline, I started this discussion shortly after buying my M56x. When I bought it, I hopped on the highway and headed straight home on the highway so there wasn't much to notice in the shifting issues.
Over time as I drove it in town I experienced what I thought was a transmission flare somewhere between 2-3. For manual transmission drivers, this felt like when you're shifting gears but then push the clutch in slightly. It mostly happened while creeping along and then trying to go back up to speed.
Not all the time did it happen, but when it did, those were the conditions.
Starting from a standstill did not show any issues. Shifting in manual didn't show any issues either.

It was a minor annoyance to me that nobody else in the car could even feel, so I just let it be. Once while at the dealer, I asked them to change my fluid and reflash the TCM.
I can't remember exactly how the reflash went, but I feel like they didn't do it and neither did I push for it. I wanted to isolate the solutions one-by-one and if the fluid change didn't work, I'd have gone back to pay for the reflash.


Looking back at Mickey's link
I wonder if a deeper dive would have shown bad solenoids as well. As much as I remember asking specifically about the fluid condition, they said they didn't see any issues. Part of me wonders how well they paid attention to that stuff. Oh well.

Unfortunately the new fluid did absolutely nothing for the issue, but since it was rare and not severe in occurrence, I kept living with it. Honestly, the only reason I could feel it was because I had another M56 to compare it with.
To clarify, yes the fluid did nothing for the car - it made it neither better nor worse. I don't ascribe to the notion that "you shouldn't touch your transmission fluid if it has never been touched."


You're probably wondering if I ever found a solution.
Well, yes, but I can't exactly replicate it .

Remember back when we all started getting anxious about the failures related to the high pressure fuel pump and started digging into it? That's the first car I replaced the HPFP lifter bucket on.
I did nothing else to the car around that time, but all I know is that when I went to work over the next few weeks, the weird flare was gone! It was also sometime in November and the air had started cooling off a little.
Coincidence? Perhaps...but since the issue seems to transcend beyond V8s, then I can't say it's a HPFP issue.
Also nobody else has mentioned any variation in behavior dependent on weather changes, so I'm going to have to imagine the car had a mind of it own. I would like to entertain the possibility of bad solenoids, but I know that such issues don't fix themselves.

Sadly, I'm never going to find out. The car was sold a few months later, having given me zero driving problems through the few months of winter.

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Mickey917
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Thank you very much EdBwoy !

Llebcire
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Reviving an old thread instead of starting a new one.

2015 3.7 AWD
92k miles, just purchased in April with 84k miles.

Shifts fine in auto, both standard and sport with normal/spirited driving. Hard driving in Sport or manual it seems to have a slight shudder when shifting but doesn't slip. I previously had a 2011 G37x that didn't seem to be as snappy when shifting but didn't exhibit this - the rear bushing was leaking in the G but I don't know if the Q70 has this issue.

Is this normal for the Q?

Thanks!

misfit77
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Car: 2013 Infiniti M56

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1. Do you feel like your transmission behaves funny, especially in city driving?

Felt good since I bought used. Terrible 1/4 mile. Feels like it takes too long to shift to 3rd or 4th, cant remember. This is in comparison to my 07 G35 sedan. That guy shifted fast and hard.
Now at 88k it is shifting realllllly funny, so funny it makes my wallet cry. P0500 and P0720. Going into dealer to get Valve Body replaced. 2 weeks up its failure the car really hesitated in taking off. I figured it was the AZ heat


2. What year is your car?

2013 M56 base

3. Is it a V8 or V6?

V8

4. RWD or AWD?

RWD

5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?

Second owner. Only had 50k when I bought it 2 years ago.

6. What solutions have you tried so far, and did it improve?

Cleared codes and tried again.No luck. Takes about 100ft before shifting issues
Fluid exchange at 60k. Used Valvoline Multipurpose Syntehtic.



Please consider this.
Got the car Uprev tuned a year ago. Since then when in tuned mode I get abrupt downshifting. Symptoms are worse if manual shifting. Symptoms lessen when in Race (high octane) mode.
Tuner said he didn't touch the transmission in the tune.
I suspect some latent damage from the tune.

Thanks again and keep up the videos

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Mickey917
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Hello !

Keeping this thread alive too :)

I can confirm that proper transmission drain & fill did NOT resolves the 4-5 shifting flare issue. Had mine done by infiniti without success.

I also try the relearning for all things possible : throttle valve closed position, idle air volume, accelerator pedal, tcm... Still flaring !

Update tcm and hybrid control module, no success.

Cleaned MAF, still no success...

Now I think about replacing fuel pump as sensor seems to be part of it. If it fails too, next thing will be around the valve body...

Chères

Llebcire
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Mickey917 wrote:
Fri Jul 28, 2023 4:32 am
Hello !

Keeping this thread alive too :)

I can confirm that proper transmission drain & fill did NOT resolves the 4-5 shifting flare issue. Had mine done by infiniti without success.

I also try the relearning for all things possible : throttle valve closed position, idle air volume, accelerator pedal, tcm... Still flaring !

Update tcm and hybrid control module, no success.

Cleaned MAF, still no success...

Now I think about replacing fuel pump as sensor seems to be part of it. If it fails too, next thing will be around the valve body...

Chères
Is the valve body issue common on the Q70?

I know that it is on the 2015 Q50 and I didn't think they had the same transmission or issues.

fuzzysig
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Car: 2011 Infiniti M37x

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2011 m37x with 187k
Every symptom on tsb list.
The most annoying of course is the upshift to 4th gear at 20mph.wtf infiniti.
And second most annoying rhing is dealership trying to charge me 200 bucks to fix their own defect.


I noticed that the upshift happens more often when turning right.
Same thing happened on all my automatic cars.
Which i dont understand

kami_sn
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Joined: Thu May 30, 2019 1:40 pm
Car: 2019 Infiniti Q70L

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1. Do you feel like your transmission behaves funny, especially in city driving?

Certainly behaves funny in City driving, especially from 2nd to 3rd and 3rd to 4th in speeds under 40mph. Also sometimes get engine brakes and city speeds and very low RPMs

2. What year is your car?

2019

3. Is it a V8 or V6?

V6

4. RWD or AWD?

RWD

5. Are you the original owner? Has it always behaved like this or did a specific event trigger these issues?

Original owner. No it did not behave like this. We have been experiencing extreme heat 105F and up, not sure if that triggered it.

6. What solutions have you tried so far, and did it improve?

Battery terminal disconnect. ECM reprogrammed to new program. Throttle body cleaned and re learned. Did not change the behavior.

Switched fuel to Shell V power from Costco (Always used Costco gas from new) , seemed to help with general car smoother behavior. I am going to use Shell V for couple more tanks to see if it helps. I am suspicious that Costco gas got something to do with this as all three of my cars started to have poorer gas mileage recently.


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