So I recently had the transmission oil changed with Nissan gear oil by my local mechanic. It was fine but now it is real notchy and hard to shift just putting it into first sometimes. Overall the shifting is otherwise OK. The temperature just went down about 15 degrees the day after I had it changed and now it has been very cold ever since. I have never had this car in a real winter before. Would the transmission do this when it is cold or does it have to do with the oil change? I don't go far enough when I drive to work and back to get it properly warmed up at all.

 

I think you will get a variety of answers.

I think unless you come to a complete stop, you should just use the 2nd gear as opposed to trying to get into 1st. The cold temperature will probably affect any gear oil; some might be better than others but I doubt there is a magic formula. I'm on the Nissan oil as well; decided not to experiment with others unless I know for sure one would work better.

 

I had the same issue when my G35 had the transmission fluid flushed. Infiniti did the change the first time, and I called them about the issue because it was worse. I took it back to Infiniti and theY mixed the transmission fluid with another fluid to thin it out. It's really smooth to shift now. I'll call my service manager tomorrow and he will tell me what it was mixed with. If you want I can give name & number.

 

Infiniti used one quart of automatic transmission fluid with the regular fluid. One quart of automatic fluid helps it thin the transmission fluid and it will warm up faster.

 

Is that a good idea????? I would be willing to do that!

 

Cold does stiffen the shift feel, even with the original fluid. That should improve as the gearbox warms up. I switched to Redline fluid, which I've had good luck with in other vehicles, but Redline does not shift as smoothly as the original fluid in the G. It is a noticeable difference, but not so bad that I am tempted to change it.

 

Yeah, it does not hurt anything. It has made my shifting smoother than ever.

 

No kidding. It's amazing that your dealer would do this. The dealer here wouldn't even say it was OK to use Mobil 1 Synthetic Gear Lube LS 75W-90 in the rear diff because the manual calls for 80W90 which is conventional and has a less demanding rating. What's the name of your dealer?

 

What I replaced with is what comes in the car new. I just wanted to make sure it wasn't due to their underfilling it or something like that. Should I get it re-checked or just wait till it warms up?

 

It's Modern Infiniti in Winston-Salem, NC. The service manger is awesome, and has always taken care of my G. He makes sure it's right the first time and if it's not he will have me bring it in asap. I'm not sure about the rear diff, but they changed that recently on mine.

 

Once you have been driving for 20 minutes, is it still hard to shift? I doubt they filled it wrong, it is too easy a job to mess up. If you feel you must check, then the next time the car is lifted, unscrew the fill bolt, stick your finger in, and verify that the fluid is about at the same level as the bottom of the fill hole.