Stick shift not shifting into a gear when driving?

[Italianfam228]

Hey y’all, so when I’m driving at higher speeds sometimes I can’t shift from one gear into another. Has anyone else had any problems like this?

[Rusty]

Need more info. Is it going up through the gears? Downshifting? All gears? Or just one gear?

[Italianfam228]

It’s usually when I’m shifting up through the gears but sometimes it’ll happen when I’m trying to downshift. It happens every so often and when it does happen I can’t shift into any of the gears. I’ve had to literally pull off the road and turn my car off and then on and then everything works fine

[Rusty]

When this happenings. Does the clutch pedal feel funny? How many miles are on the Z?

[Italianfam228]

Nah the clutch doesn’t feel any different.. I mean I’ll have to pay more attention to it next time it happens. The Z just rolled over 100,000 miles

[BGTV8]

Is called synchro's "baulking" - especially if you are trying to shift very quickly. Syncro's are failing to get the gears involved to speed-march (thats the "synconisation" part) and the gears flat-ar3e refuse to mesh ............... can also be accompanied by a "grinding" noise

Slow the shift down and let the syncro's do their job - at 100K miles they will be a bit "tired" (worn)

[Italianfam228]

Originally Posted by BGTV8

Is called synchro's "baulking" - especially if you are trying to shift very quickly. Syncro's are failing to get the gears involved to speed-march (thats the "synconisation" part) and the gears flat-ar3e refuse to mesh ............... can also be accompanied by a "grinding" noise

Slow the shift down and let the syncro's do their job - at 100K miles they will be a bit "tired" (worn)

That’s exactly what happens! I appreciate the info and I’ll try slowing it down. I didn’t know that was possible lol

[POS VETT]

When was the most recent transmission oil change? Which oil?

[Cyber370]

Originally Posted by POS VETT

When was the most recent transmission oil change? Which oil?

Yeah. I was gonna bring up the tranny fluid. Are you sure the right type and viscosity of fluid was used? That’s if it was ever changed. If not, then try changing it.

Wrong tranny fluid (if too slippery) can cause synchro issues.

[SouthArk370Z]

Check to make sure the clutch is fully disengaging. Zs are infamous for CSC and CMC failures.

You may have a (engine, trans, etc) mount that is broken and allowing the transmission to get in a bind.

As mentioned above:
Synchros may be worn.

Wrong lube in transmission.

[Italianfam228]

Originally Posted by POS VETT

When was the most recent transmission oil change? Which oil?

Sorry for the very late reply.. the transmission fluid was changed when my csc failed about 20,000 miles ago. I wanna say they used redline NISMO fluid or something like that.

[Italianfam228]

Originally Posted by SouthArk370Z

Check to make sure the clutch is fully disengaging. Zs are infamous for CSC and CMC failures.

You may have a (engine, trans, etc) mount that is broken and allowing the transmission to get in a bind.

As mentioned above:
Synchros may be worn.

Wrong lube in transmission.

Yeah my csc went out about 20,000 miles ago.. luckily no issues with the clutch yet

[NissanZ34]

Originally Posted by Cyber370

Yeah. I was gonna bring up the tranny fluid. Are you sure the right type and viscosity of fluid was used? That’s if it was ever changed. If not, then try changing it.

Wrong tranny fluid (if too slippery) can cause synchro issues.

Hello. I am having the same issue as OP.

I have just purchased some Redline Mt-85 and Redline 75w90. I am wondering if my transmission (synchros) is/are about to give up or I may just need a good oil change.

My car has about 30 000 miles but I beat on it pretty good. The car was shifting fine when I first got it but after 3500 miles it shifts clunky now.

The dealership mech said it's probably the synchros. They are able to order 1&2, 3&4 and 5&6 synchros in a "2 gear pack" or simply the whole transmission assembly. The synchros are back order at the moment but the transmission assembly is available for order but it's 2500$ though.

Redline fluids cost an arm so I'm wondering if I should just keep driving the car as it is for this season, OR have the transmission fluid changed for the oem oil for this season see if it helps in any way OR report the transmission swap for next season and have brand new oil and transmission together OR change the fluids now and hope for the best.

I really would not like to waste that Redline oil.

I thought my transmission rebuild would have only happened under forced induction... oops

Thanks for helping me out.

[SouthArk370Z]

Originally Posted by NissanZ34

... My car has about 30 000 miles but I beat on it pretty good. ...

Then it's time to change the trans lube. There's a good chance it will make your problem better and may even fix it.

[NissanZ34]

Originally Posted by SouthArk370Z

Then it's time to change the trans lube. There's a good chance it will make your problem better and may even fix it.

Cool. Do you think I should use my high end Redline MT-85 or use the factory oil? I asked them and they said it's 75w85. Can you confirm that?

By using the factory oil I could try and see if the oil change fixes anything, at a lesser expense. I would keep the better quality oil for later on.