Hey guys,

My car is 2005 350z 6 speed MT and I'm observing a very strange issue with my transmission. Quite often when the car comes to a stop at the traffic light the transmission won't go into gear at all, but when the car is moving (even if it's moving very slowly) no issues getting into gear.

This would rule out any issues relating to clutch and the slave cylinder, correct? Transmission does not grind at all when shifting from gear to gear so I don't think there is an issue with the synchros.

No issues going into gears when the engine is off as well.

It's so weird I just get locked out when the car comes to a complete stop (with the engine running).

Any suggestions or ideas would be appreciated.

Thanks in advance.

 

Have you done any troubleshooting at all?

 

Thanks. The thing is I don't even know where to start. I was told by a tech the master/slave cylinders are ok, the engine mounts are fine and he sees absolutely nothing wrong from the outside.

He says the only next step is to take the transmission apart but I'm wondering if it's just causing issues when the car is stationary, is taking the whole transmission apart necessary/the only way?

Thanks.

 

Start with simple and cheap, flush and bleed clutch line, then dig deeper if needed

 

Have you done the Cmc adjustment behind the clutch pedal?

 

Hey Edneil, it sounds like we might have a similar issue reading your other thread.

I'm going to flush/bleed out the clutch fluid and look into replacing the slave cylinder as well.

It just doesn't make sense as when I get locked out, if I let the car drift forward 10~20cm while the clutch pedal is depressed and with my hand trying to push the gear lever into 1st gear with very light force, it goes in smoothly. Then all the gears are accessible even when stopped.

BUT, when I let the clutch pedal out then depress again I get locked out again. If I let the car drift 10~20cm forward with my hand applying a light force to get into 1st gear, it goes in again.

Absolutely no issues shifting when the car is moving.

It's like the movement of the drivetrain is "unlocking" something and letting me go into gear. Thinking about how the manual transmission/clutch work I know this doesn't make sense

 

You owe it to yourself to do the master and slave cyls just to be sure before you pop the housing.

 

Another solution is to try driving yourself out of a shifting problem. Heel-and-toe downshifting has been used for a long time, and might be useful in this situation. The technique remains the same: approaching a stop, use your right foot to begin braking. While doing that, declutch and put the gearshift into neutral. In the same split-second, rock your right foot, so either your heel (or the outer aspect) brushes the throttle. Raise the revs just a few thousand revs, before engaging the clutch and slipping the gearshift into first gear. It should go in quite easily before coming to a stop.

 

It sounds like your pressure plate is dragging on your clutch disc, never allowing IT or the input shaft of your transmission to come to a stop; hence, not allowing you to shift into any gear while you are at a stop. My guess would be a warped/bent pressure plate or weak/broken pressure plate return springs...

 

...or air in your system(a lot of it). Try bleeding it first like stated above.