Hi Guys,

I've always been amazed at all the knowledge going around this forum.
I love it!

Anyways, I was wondering if anyone has any input on what exactly transmission "slip" is?

I've been having a problem with my Autotrans on my '07 G35x lately.
It seems everytime i have it in "D" mode and it changes gears from 2nd to 3rd OR sometimes 3rd to 4th, it feels like something/someone is kicking the back of my chair (or love-tap from behind). Is this a "slip" in the transmission? (this is just normal driving btw 25-40mph) If i accelerate fast, this symptom is somewhat muted.
It happens in DS mode too :/

It seems like its auto-shifting at the wrong time? I notice this auto-shifting happens between 2200 RPM and 2800 RPM. All other RPMS, the shifting is smooth.

I have to drive in manual mode now so i can control when it shifts for smooth shifting (usually around 2000 RPM or 3000 RPM = smooth shifting).

The car's at 40k mi. and I plan on doing transmission drain and fill 3 times over the next 4-5 days.

Please any input is always appreciated.

Thanks!

 

You're not alone, I've been dealing with this problem for about a year. Have an appointment with the dealer, but I'm doubtful they'll be able to "reproduce" it since that is the claim they've given me before that seems to get them out of actually figuring out what the problem is and rectifying it.

 

Simplified, it's when the gear change is sloppy. That is, it won't engage when it needs to, or it'll disengage. This is usually felt as a rise in rpm but no immediate change in speed. Not to be confused with the rev-match feature.

 

I suggest taking a video of it. It'll help your cause if you have proof of it.

 

Thanks for explanation Soundmike. I guess my issue is not transmission slippage then hehe. I can feel it accelerating at all levels of RPM. It's just that it "jolts" like someone just kicked the back of your seat as it switches up into the next gear. It doesn't "jolt" when it downshifts though. Rev matching still works perfectly...

i can easily replicate this in "D" mode. i just accelerate moderately and at the 3rd shift, it shifts around 2500 - 2700 RPM into 4th gear ... and that's when it happens... everytime.

I'm always like...WTF, did someone just rear end me ...again?! lol.
Anyways, if my transmission oil change doesn't fix it... I'm gonna see what the stealership has to say ...

Hey Voltagefx, can you let me know what your dealership says about your situation?

 

same thing being felt since 2008.

 

So all 2007-2008 g35x's have this problem?? That sux :/ Anything out there that can fix this (besides a new transmission)? It's just so annoying

 

Yeah, I'll let you know what they say. It's hard to get on camera since it's "felt" more than heard for me... It would probably jolt the camera a little, but they could say I'm doing that myself.

 

^ if it's a tranny slip, the gauge cluster will show the issue coupled with the sound of the engine.

Although, if it's not a slip the video certainly won't help much.

 

same here..it is "felt" more than heard.

 

I have this issue, but only when I am in DS and it shifts from 2-3. It only happens about midrange RPM. When I am going flat out, it is smooth. When just lazy footing it, it is also smooth.

Since it only happens in DS, I am not worried about it. Seems like the tranny wants to shift quicker in DS (not sure if it is just mental) or when using the paddles.

 

I also have this. It's just a bonus that goes with the shudder issue.