Planning on rebuilding the trans in my s5 na gtus. The trans whines pretty bad from what I believe is either the input shaft bearing or the pilot bearing going out. Either way, while I have the trans out of the car I might as well open it up and inspect the insides.

So my question is, is there any specific rebuild kit that people on here have had good luck with for the s5 na trans?
On this website : Manual Transmissions by Unit Code: RX7 & RX8 series: Manual Transmission Parts - Online
I found that I could use this rebuild kit: BK137CWS
That looks like it matches up to my trans.
any input would be greatly appreciated.

 

You wouldn't be hearing the pilot bearing as it just allows the input shaft to continue to spin while you shift gear.It's basically a "guide" to keep the input shaft on the trans and the eccentric shaft straight but yet act as separate parts.
The most common way that it has failed shows up as the inability to shift gears when the engine is Running,as the trans and engine are locked together(due to a fused/bad pilot bearing).

Does your "noise" start when your trans has the car in motion?..if so that may be a front bearing or syncro issue.

 

The noise occurs when the trans is in neutral, with the clutch engaged (pedal up). It is a loud "whirring" noise. The noise goes away when I push the clutch to the floor.

 

sounds more like a release bearing.

 

The noise doesn't go away until the clutch pedal is pushed at least half way to the floor, which makes me think that it is not the throwout bearing. I thought that the throwout bearing would whine until the clutch pedal was pressed just a tad, which would make it stop whining, which is not the case with my trans.

 

IN my experience the vast majority of times that a car makes whining noises in neutral and first gear the issue is in the trans and not the PB or TOB/RB. IT could be the input shaft bearing or worn teeth on the input shaft/main countershaft gears. I do not really do much trans internal work but I think you are on the right track to take it apart and try to rebuild it. Note that the GTUs 5th gear is different than all the other NA 5 speed models so you will want to hang onto that, even if you have to replace other parts as part of your rebuild. Unfortunately I have no other info to offer, but I do know that pineapple racing and some other shops used to rebuild NA trannies with miata gear sets for closer ratios and more acceleration, so you might want to look into that as well.

 

It's a throw out bearing...been there.,

 

With the clutch pedal properly adjusted (no preload) the throw out bearing is not spinning or touching the pressure plate at all when the pedal is at rest. So how could it be making noise when the pedal is at rest if it is not turning?

The throw out bearing only begins spinning when the clutch pedal is pushed and the bearing is loaded onto the pressure plate. A bad TOB will make noise when the pedal is PUSHED, not when it is at rest. Now, if the clutch pedal adjustment is preloaded, then the TOB will be contacting the PP at all times and spinning at all times, and you can get noise from it with the pedal at rest.

 

I'm in reverse today..scratch that!

 

You worded that perfectly, thanks for the input. I wish it was the throwout bearing... would make for a much easier fix!