hello everyone. I have been the proud owner of a miata for about 4 months and i started to notice a problem with my vehicle. Sometimes the first gear will not engage, it will be half way or 1/4 of the way in but it will not engage it. I solve that problem by double pumping the clutch and then the gear will go in. I also noticed the shifts are notchier specially the first three shifts (manual five speed). I read in other forums that this could be caused by a failing slace cylinder and/or master cylinder. Could the slave cylinder cause that notchy shifting as well? I already replaced the clutch fluid and it was about the same darkness as engine oil. I am planning on replacing the slave cylinder tomorrow morning, i just want to get some feedback so i do not just randomly start throwing money on parts that do not need to be replaced. On the other hand, i also refilled the shift turret with some 75w-90 oil i had in my cabinet and it did make the shifts smoother when the vehicle was off but, when i turn it on it just merely goes back to its notchy feeling. I am planning on replacing the tranny fluid in January since the vehicle barely sees the streets. Thank you in advance.

 

The slave and master for the clutch are both easily suspect if the fluid was not clear and it doesn't shift well. You are correct in changing them, and they are quite cheap.

 

Yesterday, i replaced the slave cylinder because i noticed it had a lot of fresh fluid on it. I did notice a slight increase in pressure in the clutch system but, it did not fix the problem with the notchy shifts. I also went on to replace my transmission fluid with the good old motorcraft stuff ($21 a quart) and that did smooth out all the notchiness out of the 3 4 and 5 gears but not the first and second gears. I went out to run the car with the new fluid and i dont need to put a lot of force anymore on the first gear like i use to but the notchy feeling is still there. My second gear when shifting into it, you can hear a lot CLICK and my reverse gear occasionally grinds a bit when engaging. I will be adjusting the clutch today see if that does anything positive on my car. Thank you for your response. If it helps in anything, my old tranny fluid was darker than engine oil and had a lot of particle matter that made it seem like it had dirt in it (similar to having murky water on a bottle).

 

Dirty clutch fluid indicates moisture which causes corrosion in the system. Between that and the rubber parts disintegrating it can make it look nasty. The clutch master seals are made of the same material as the seals in the slave so expect that to need replacement, too.

There is a good description of how to set the clutch pedal free play on Flyinmiata.com in their maintenance section, iirc.

 

i will replace the master cylinder in the coming days, see if it does anything. While i was driving my car, i noticed that second gear would "clack" if i tried to shift it in fast. However, if i took my time to shift it in (1-2 secs) it would shift in smoothly and with no "clack". Could it also be that my aluminum shift **** is affecting this?

 

It has to do with the synchros of the transmission. If the clutch doesn't completely disengage then the speed of the input shaft doesn't slow enough to allow the gear change quickly.

It is also very important to bleed all of the air out of the hydraulic system once you get the parts changed or it won't work well.

Start at step 6. http://www.flyinmiata.com/support/in...isc/Clutch.pdf

 

The master cylinder will arrive tomorrow morning. I will install it as well and see what results i get from that. Thank you so far for your help!

 

Good luck.

 

sorry if i have not replied yet. School and work has taken a toll on my free time now. I replaced the master cylinder but sadly, it has not fixed the problem. I have replaced the tranny fluid with motor craft stuff everybody seems to recommend, replaced slave cylinder, and the master cylinder. The car still has notchy shifting specially in the first gear and third gear. Sometimes when i am in a complete stop, i would press the clutch and i would not be able to engage the first gear at all unless i double pump the clutch. When this happens i can shift into other gears except first gear. I also need to wait about 5-10 secs for the reverse gear to engage. I adjusted the clutch to the specs that i found on another miata forum but it only made my engagement point moved a little more towards the middle. I honestly do now know what else could be wrong with it. By the way, i did bleed the clutch hydraulic system. Thank you for your help.

 

I also would like to add this. When the clutch is used a lot like in a city, the notchiness would be increased considerably, i would literally have to engage first gear in two motions (go in gear, stop mid way, go full way into gear). I think that maybe as the clutch fluid warms up something prevents the clutch from disengaging fully thus causing the notchy shifting?