Hi everyone,

I'm a new member, but long-time owner of a 2007 G35S 5AT with just over 50k miles. Recently, I've noticed a shifting issue from 2nd to 3rd gear. There is a slight shudder or jerking feeling when making the shift, it's not as smooth as the other gears. This only happens when the car has warmed up, under light to moderate acceleration. It will not happen if the car is cold or when it's first driven, or under heavy acceleration. It also does not happen when using the paddle shifters.

I've had the ECU update done, transmission fluid was replaced four months ago with Nissan Matic S (all looked fine), and otherwise very well maintained. The dealership is struggling to determine what is wrong with it. First they said it felt unusual and thought it may be the valve body or torque converter. But there are no error codes so they gave it back to me and said there was nothing to fix. I just took it to a Nissan dealership, they felt the issue, but are also not sure if it's normal. Here are the notes:

"Customer states harsh shift in transmission. Verified customer concern, vehicle has slight loss of power then engagement in third gear during light accel, monitored data using consult and found the cause is the torque converter clutch engaging in 3rd gear, on heavier accel the torque converter locks up in 4th gear instead and nothing is felt, unable to determine if this is a normal characteristic of this transmission and inspection shows fluid condition and level is normal."

Does anyone happen to know if this is normal? I've read there is a harsh shift from 2-3 with the paddles, but mine doesn't do that, only when in D/DS mode. Short of tracking down another '07 G35S to test drive I'm stuck. Any help would be much appreciated.

Thanks!

 

"unable to determine if this is normal" HILARIOUS. Leave it to the dealer to find an issue..but have no clue how to fix it.

They should have called corporate and/or asked them to bring a tech out there. That's what they did when my engine blew because they had no idea what was wrong. They brought in a tech that travels the country I guess who is from Infiniti directly.

Probably the TC but it is not normal. My 5AT in my X doesn't do that. I only have the 40 MPH shudder that everyone else has.

Keep going back and back and back until they finally decide to do something. You are out of warranty correct?

 

I am out of factory warranty just by a few months, but I do have a third party warranty that covers the entire transmission and powertrain. They said as long as we know what it is, they will cover the cost.

It's scheduled to go back to the dealership on Monday. I spoke to the service advisor last night and he's going to recommend replacing the transmission, since they think it's either the torque converter or valve body. I'll certainly update, it's just frustrating that they can't tell me if there is anything wrong for sure.

 

i know how you feel...been through the same thing (not tranny issues but other issues the dealer can't/no one can fix)

 

I have the same problem with my 2007 G35 Journey with 70k on it.

Its done this since I bought it and when I pointed it out to the previous owner during the test drive he says it has always done it too.

Changing the transmission fluid did nothing to alleviate the issues, however after 10k miles I changed the transmission fluid again and now the issue is less noticeable, but still prevalent.

From what I have seen on here it sounds like a known issue that a certain % of G's are faced with.

Odd thing is, mine only does it in automatic mode. If I go tiptronic, it will not do the 3rd gear blip. Also, under harder acceleration it doesn't do it, and under super light acceleration it also doesn't do it.

It's at around 2100 rpm under normal acceleration conditions.

Odd but I learned to live with it. It has never gotten worse, only slightly better with the 2nd oil change.

Weird stuff right?

 

I have the same car as you and was curious about this. I just finished taking a drive and can say that I do not see this issue. Using light to moderate acceleration from stoplight to stoplight my shifts are smooth without any jerking. I have seen the rare harsh shift, but nothing on a regular basis.

I have 116K miles and did just have a drain and fill done a few months ago. I cannot recall noticing anything like this before the drain and fill was done. It could also be that the issue never really stood out to me.

 

Mine too. i asked about this to a guy that works on transmission and he says it's normal. Between 2nd to 3rd is less slippage and the gears are just catching faster. I been to 3 different dealers and they can't find anything wrong w/ it. When i did the valve body upgrade to my car the guy said my transmission was healthy and nothing wrong on the inside.

 

Thanks for the replies. Mike, you described my issue perfectly. It's funny to hear that some people have this and others don't. In either case, it's back at the dealership again and we'll see what they have to say. I'll definitely update once I hear back.

 

Just to update for anyone that has this issue and might be curious, it was finally determined the stator in the torque converter has failed. Fortunately my warranty is covering it, but that is the issue causing the shifting problem. He said this is fairly common in the 07/08 G35's.