After having my 90,000 mile maintenance done at the dealership (they replaced the automatic transmission fluid during this maintenance), I have noticed the transmission started to act a little weird. Every so often, when I put the car into park and turn the car off, the dash yells at me to shift the car into park even though it already is (the shift led is in P). I would press the lock thing on the front of the shift **** and the car will then recognize it is park and let me turn it off. Also, I began to notice that the car shakes when reversing up a steep incline and that I had to rev the engine up high in order to get the car to move. Today, the transmission seems to have completely gone bonkers. The car can shift into P, R, N, D, and M just fine, but reverse feels like it stays in neutral (even though the indicator led says it is in R, as does the instrument panel, and the reverse camera turns on). The car does not move, and I can rev the engine up high and the car remains still. I can put the car in drive and it moves fine. Any idea what could be the issue?

 

Hmm, I can think of at least 3 things it COULD be:

1) Your tranny was very worn and your fluid had thus gotten very dirty with all that wear contaminating its fluid, but it was essentially acting as a "friction modifier" and was keeping the shifting operation working "ok". When they serviced the tranny, they flushed out all the old fluid and put in nice clean (unmodified) fluid which couldn't provide the friction needed to operate the worn tranny clutches.

2) Your shift linkage is loose and is allowing the shifting action to suffer so that it is not fully engaging shifts at the tranny shift input.

3) It could be that one of your valve bodies in the tranny has bit the dust.


BONUS: 4) It could be any combination of the three.

 

I pulled up the service manual and in the section for "Slips/ will not engage with the shift position in R", it says the first thing to do is check the A/T fluid level and state. I just checked it and it is pitch black, not red. Do you think this could cause the reverse gear to not engage or is this step more of a formality?

 

Well of course low fluid would be the first thing to check, but you said it the fluid was just replaced by the dealership so I figured that was eliminated already. Now that you say the fluid is pitch black, if the service was done recently, I have serious concerns about whether they even did the service or not.
Was this an Infiniti dealership?
How long ago was the tranny service done?
Do you still have the service receipt?
What does the receipt say about the tranny fluid?
How was the fluid level when you checked it, was it full?
You said it was pitch black, did it smell burnt?

 

The service was completed at my local Infiniti dealership 2000 miles ago ( 6 weeks ago). The service receipt does say they flushed the transmission fluid and put new fluid in. The fluid did seem full, it was past the full mark for both the hot and cold side of the dipstick. I don't recall a burnt smell, but I didn't really smell it, just looked at it. When I get back home, I'll check the smell and reply back. I also went ahead and scheduled an appointment with the dealer for Friday, but if it's possible, I'd like to fix it as soon as possible, parking with no reverse is going to be hard and driving the car at all doesn't seem like a smart idea, but it's my only car.

 

Decided to go ahead and change the tranny fluid. It came out looking like chocolate syrup (color wise, not viscosity). I held a coffee filter as I drained the fluid from the transmission and when I put the fluid into another container for recycling. In both cases, there were less then 5 smaller than a grain of salt sized sediments (definitely nothing larger than 1mm, which the service manual said anything under 1mm is okay). I put in new transmission fluid as described in the service manual. Reverse still acts like it is in neutral. The car does shift both up and down a lot smoother in the 5 forward gears in both D and M modes. I also went under the car and had someone else shift the car into P, R, N, and D to see if there is a problem with the shift linkage, but each shift did move the shift linkage and the lever attached to the transmission. The shift linkage in general seemed fine, not loose and no missing parts that I can see.

I also failed to mention that before the reverse went out, I disconnected the battery to reset the radio. After I did that, when I put it in D after reversing out of my driveway, it felt like the car was in neutral. I put it in park, turned the car off and then back on, then put the car back in drive and it drove forward like normal, but then that is when reverse started to act like neutral.

Is it possible this could be caused by an electronic issue?

 

I'll keep updating this post in case anyone else has a similar issue as me in the future. I will be dropping the car off at my local AAMCO. Fingers crossed that it is a simple electrical switch or solenoid issue considering that all of the gears were working before the issue started. That being said, I have by bet on the valve body needing to be replaced, which will probably cost $1500+. I'll update again once I get the car back from AAMCO.

 

I'm having a similar problem on my 08 G35X it seems. After letting the car sit for half an hour, it requires 500 or so RPM's in order for it to move after putting it into gear. I feel the car engaging into gear, press the pedal, and get no movement. If I press a little more it will "slam" into gear. Is this similar to the problem you were experiencing? fyi car just had it's 100,000 mile checkup performed which included tranny flush n fill.

 

Sounds like low fluid level. Try changing the fluid and see it that helps. I hope you can get it going soon man..

 

did you get to the bottom of this?? i have same issue

 

So much for keeping us updated. Mine started this today. Tried to back out of a parking spot and revved it like it was in neutral. A few more attempts got the same result. I shut it down, restarted and everything worked fine.

It only seems to be reverse. Each time I put it in P, engine running or not, I lose reverse. A quick restart and all is well. This has got to be electrical.

 

having this same problem i assume its the shift linkage but i cannot find the part anywhere

 

Did anyone figure out this issue ? Im about ti get the transmission fluid flushed today ti see if thus changes anything

 

Did you check your transmission fluid level?

 

I have a 2015 QX60 and it recently started acting like it was in Neutral when I put into reverse. Turning it off and turning back on fixes it and it acts normal. I'll check the transmission fluid. Hope that fixes it.