6th gear syncro
 

I just returned from the dealer, my complaint was 6th gear grind from 4th to 6th.
Even though they were able to duplicate the problem, their response was that I must follow the shift pattern. I explained that I have been driving that way since the car was new and just started having this problem @ 17K. Nissan corporate
advised them tell me....follow the shift pattern. Anybody with similar problems?
If so, How did you get the dealer t repair under warranty.

So you are shifting from 4th to 6th(skipping 5th) and it's grinding?

So riddle me this, can you shift from 4th to 5th to 6th without making your tranny grind?

i think this is the problem: you are used to waiting for hte flywheel to fall in between gears. It usually takes the same amount of time between any two gears. When you're skipping gears, you have to give it more time for the flywheel to slow down to where it needs to be for a gear thats 2 gears higher than the one youre in.

IE, shift at 7k out of first into 2nd and dump the clutch you'll get a little chirp. Shift at 7k from 1st to 3rd and dump the clutch your RPMS are way to high for how fast you're going in 3rd gear -> gear grind. same thing at the higher gears.

I an having a 4-6 grind also. There is also a grind in 6-5.

I have driven like this in many sports cars for the past 10 years and this is the first time I have ever got a grind from a normal 4-6 shift.

Syncros keep the gears from grinding. If you skip shift too quickly, you ride the clutch and the engine forces the rpms to either drop or rise quickly to match up. Perhaps it causes more wear on the syncros and thus the problem of grinding after 17k miles.

Is this only in sport mode?

Just cause you starting shifting this way from the beginning doesn't make it right. Shift like 90% of manual drivers. This will avoid future problems.

There is NO reason you shouldn't be able to shift from 4th - 6th.
Hi-Revs to Lo-Revs should not be an issue.

However, I can't say the same for 6th - 4th :eek:

+1...

4th, 5th 6th
 

I can shift 456 with no grind, although 6th feels a little sticky. I don't have the sport package so rev match is not an issue.

At about the same mileage I had the same issue rear it's head on my Z. 4th > 6th ground every time, and 5th > 6th was about 30%. Happened under low/high revs, slow/fast shifts, s mode on/off. Didn't matter. It was more prevalent during higher revs as well as more obvious, but from 4th > 6th you could feel at least one "tooth" as you were moving through the gate.

Went to 1 dealer and they gave me the runaround and ended up blowing me off. Went back to the dealer I purchased my Z from after that, and explained my issue and the issues I had with the other dealership. I told them that my 6th gear synchro was failing, and that I needed a new transmission installed under warranty. I also requested that they have a loaner vehicle waiting for me as I needed to drop my car off and be gone within 15 minutes. They did exactly as I requested and had my transmission replaced in about a week.

Some techs try to avoid work and even are misinformed per the Nissan tech line. Grinding for 4th > 6th or at all with full clutch depression is an issue and should be handled under warranty. Nissan's method of transmission "repair" is to replace the entire unit and let the factory inspect the original unit at a later date. I like this idea :tup: