For a while after I picked up my new 2011 IPL in October 2011, everything was great. As soon as I got out of the break-in period and started driving the car more agressively I felt something wrong. By the time I reached 5,000 km, I noticed grinding going into 6th gear...especially when coming out of a lower gear ... like 3 or 4th. The problem got worse and after several visits to my closest dealership, the transmission was replaced with the belief the snychros had a problem (replaced at 12,000 km or so). After putting 3,000km on new transmission, the same problem is coming back. I have been to the dealership and showed them the condition when gear grinds and they said they couldn't do much because it was under very specific circumstances that the transmission would grind. Other than not having clutch engaged, there should be NO circumstance when gears grind that I am aware of. I called them 3 times since, with the last one to set up an appointment now that the car grinds pretty much every time into 5th and 6th and sometimes 3rd. Now the transmission needs top be replaced for sure after the amount of grinding that has taken place. I LOVE the car otherwise but unfortunately ... now.... I want out of my lease !!!

 

Lemon Laws, look into them for your area.

 

Thanks. I just spent some time looking into lemon laws but they are a bit different in Canada. There is still a process to follow though. It really surprises me that the tranny failed twice. It may be related to increased HP & redline for the IPL while using the same tranny as regular G37. The difference is not that much but maybe that, in combination with reasonably agressive driving takes it over the top. Thanks again.

 

Do you often come out of 3rd or 4th gear into 6th? Synchros probably are your problem. It sounds like how you are driving it may be a huge factor.

 

Yes...it is common for me to accelerate quickly up to speed (highway speed for example) and then to shift directly to 6th until I have to slow down again. The way I drive likely comes into play but I am not doing anything to "abuse" the car. As a matter of fact, I had a 2008 G37S before this one (for 4 years) and drove it much harder without problems. I believe you are right about the synchros being the prob.

 

You may not think the way you are driving the car is abusing it. Obviously your transmission(s) would probably beg to differ. I can predict that if you keep driving your car like you currently are you'll keep screwing up synchros. And there have been relatively few MT failures that I'm aware of (CSC and master cylinders are a different story). It's highly unlikely that you got two separate defective transmissions in under 20K km. It's a lot more likely that the way you are driving it is wearing out the synchros very prematurely. Just my guess.

 

I agree with Black Betty, I am not sure why you would even drive that way to begin with. Really I wouldn't think it would make a difference but like was stated, your tranny is thinking differently. One bad tranny maybe, 2 in a row not very likely at all. Also note the fact you have an IPL has nothing to do with this at all.

 

Did I read this right, He is going from 3rd to 6th? What happend to 4 and 5?? AHHA
I would almost assume this is the issue.

 

This is clearly a hardware failure issue, how can the driver been blamed for a device that was built to handle such manner of driving under NON-FI, it's not like the OP has a FI application installed. That being said it might be best for Infiniti to replaced the faulty car with a new car instead of replacing the Tranny.

 

Must be all that extra power the IPL comes with. Tranny cant handle it.

 

Thanks but these cars are designed to be driven...or at least I thought so. I am not driving a $15K car here. I have never track driven it...maybe hit redline once and did not sustain it...big deal. I never take TSC off...I don't "spin" my tires. I do corner agressively and accelerate agressively. I have driven many, many other MTs over the years and never seen the same problem. However, I did mention this issue to someone I work with who has a G35 and he is experiencing similar issues but on a smaller scale (less grinding). There is nothing in my manual or even common sense that restricts shifting from any gear into any other with the exception of watching redline. I am not going to let a faulty transmission dictate how I drive. I will dump the vehicle and buy one that is trusted.

 

Yes i am...If I am at 60mph in 3rd...why shift through 4th & 5th to get to 6th...ridiculous.

 

Thank-you for the support WarPeaceLove. I am surprised by some of the comments I have heard from others. Even if I could somehow abuse the car, I can't imagine synchros going in second tranny 2K after it was put in. Some readers might be suggesting I keep the car under 4000 rpm, only shift in perfect order, and make sure I have no tire wear as well...NOT going to happen.

 

This isn't entirely true. If you are just dumping the clutch while shifting in any gears. It will make the syncro's wear out very very fast. The clutch on the G is very very not forgiving. I learned that the hard way when I first got my car. My 3rd gear synchro was shot after just 6 months of driving and found out it was my driving style. I was letting go of the clutch to early and to fast. Once I slowed down the clutch engagement everything seemed to be fine. I got my replaced at 6k miles and its going strong at 59k miles plus without any kind of tranny problems.

I also track the car ALOT and yet ran into no problems when I was shifting correctly.

 

Thanks for the info DashKid....interesting. Can you please explain what you mean by letting go of clutch too early and too fast? I thought if you are driving aggressively (especially on track) that releasing clutch too fast after a shift shouldn't be a problem with a car like this. I always blip on shifts which should remove/reduce stress from shift.