I'm posting this in the Canada forum as well as the tech area because I tend to get a quicker response here and I would like to know what dealers are good in Ontario.
My tranny in my G sedan has always been a little notchy sepecialy going into second gear, the other day I was driving to work I pushed it off the light and misshifted into second gear since then I can't shift quick into second without grinding (most of the time). It wasn't smooth before but now its a little worse the car is still under warranty but I'm not sure how to approach them with my problem, if I swich slow into second at high rpm's it won't grind but if I switch quick enough to chirp second most likely it will grind. Have any of you brought your car to the dealer with this problem? will they cover a syncro problem?

 

well, mine is about the same...(2004 coupe m6)

I sometimes just skip the second gear on morning going out of my driveway and get it strait in third..

I got the syncro replaced in my previous car, a 2002 acura RSX, It was worst than the g35. It didint really changed anything, there was a TSB released for the acura s-type for the second gear syncro.

 

If I were getting some work done, I'd go to Oakville Infiniti or Guelph Infiniti for service.

G/L with repairs.

C.

 

Have you changed the oil in the transmission lately? I use to have the second gear syncro crunch with the factory fill. When I changed the oil .... 2'nd gear crunch is now gone.

 

Skipping gears on the upshift is bad for your transmission.

G-MAN can you elaborate on this "I pushed it off the light and misshifted into second gear"

I don't understand what you mean by misshifted into 2nd? Did you grind going from 1st to 2nd? Or did you go from 3rd to 2nd instead of 4th?

 

By misshifting I mean grinding from 1st into 2nd at high RPM's, the wife and I had an arguement and I took off quick because she made me late for work, because I was frustrated and not concentrating I shifted too quick into second before I had my foot all the way down on the clutch. Because second gear has that click/notch I thought I was already in gear but I wasn't, I had a feeling this would happen because of the way the 2nd gear is.
I hope this explains in enough detail for you.

 

You may have damaged the dogteeth then. If you were half in and released the clutch that’s not good. Synchros don't help much when the teeth are rounded.

I would try changing your fluid. But I suspect you did some damage.

 

that's a negative....

 

LOL.. alrighty.

There is too much rotational speed difference in the layshaft between the high and low gears and could be very hard on your synchros.

But do whatever you want and find out the hard way

 

well....I dont really think that there is a big rotation difference in most of my situation. In the g35 the second gear ratio is strange, seriously I just fly through the second because out of my driveway, it's a downward slope and when leaving first gear around 2500/3000 rpm to reach 40/50 km/h I allready have too much speed to smothly engage the second gear.

 

Syncros are designed to aid a downshift not an upshift so unless you let the rpm drop for the higher gear you're causing extreme wear.

 

yeah RPM has definatly drop because on "day to day driving" I shift slowly. I let go the gaz pedal because I allready reach my cruising speed in that particular situation with the third gear engaging at around 2000/2005rpm at 40/50 km/h I think there is not much "excessive" force required by the syncro to match RPM passing over the second gear.

Anyway, I will give the guy his thread back but I consider your comments, My second gear syncro are not smooth and I dont want experience the same thing with the third so I consider any comments to prevent that.

 

Think saw you post in other threads, but there are a few G35 that have had problems with 3rd and 5th gear grinding. There is a problem with the synchros, I would say check with a dealership to get the tranny replaced.

 

Thanks for the imput guys I'll be checking it out soon it has gotten better though. Have any of you tried another oil? when I had my Maxima I changed the tranny oil to Redline MT-90, it did improve the shifts a bit and it doesn't damage the syncros like some aftermarket synthetic oils.

 

I recently flushed my transmisison fluid and finally decided to get mine from Nissan..

Even if "redlineoil" are high quality product, they dont make your "grade" requirement from Nissan. I spoke a "Redlineoil" tech and he told me to mix two oil grade to get that specification...here what he said:
-------------------------------------------------------

In the G35 transmission where a 75W85 viscosity is called for I would
recommend a blend of MTL and MT-90. The capacity appears to be just
over 3 quarts, so 3 quarts should be sufficient, I would use 2 quarts
MTL and 1 quart MT-90.

In the differential I would recommend the 75W90.
"
---------------------------------------------------

I also heard about people having syncronisation problem in 350z/g35 in winter(cold temperature) using "redlineoil"....I get -30 degres celcius around here in winter...I definatly want to be able shift gear in those mornings!!!