first off, im sort of new to this forum, ive been following for a while but never posted. so i have a 2004 rx8 with only 40 000 km about 23000 miles dunno for sure in miles. so my problem is high rev gear changes. when i get up to about 7500 rpm to 8000 rpm, shifting from 1st to 2nd. i dont power shift or anything but it grinds when i go into second and the clutch is fully depressed. i would under stand if i was trying to shift fast as i released the clutch it may grind but is this a common problem. im not 100 percent sure im explaining it proper but any suggestions?

 

I know exactly what you are talking about.
I've had this problem since my 2005 was new!

I should have insisted on the dealer rebuilding the transmission but I didn't ... oh well.

So I would also experience this going from 2nd to 3rd

It only does it if I try and shift to fast and yes like you I made sure the clutch was fully depressed. (at first I thought it was me shifting without the clutch depressed fully)

As far as I can tell or have bothered to research about it is that well basically the transmission in our car is ****. Syncro's aren't with the steel they are made out of.

I did find that changing the trans fluid with Redline helped considerably.

Other than that I've just learned to live with it and shift slower, I pause for a split second in the "home" position if you will before going in to the next gear.

2005 MT with 90,000 km's -- still the same shitty transmission

 

Change your gear oil. My 6mt grinded like this both upshifting into 2nd at >6k and downshifting to 2nd at >20mph. Replaced it with RP and it got worse. Replaced it with Pensoil Sycromesh and a couple squirts of Lucas Oil Treatment. Took about a month for everything to work in and get the full benifit, I think it was gunk on the bearings. After that it's been smooth as butter. Only grinds if I screw up, or if I drive hard before the transmission warms up.

 

thanks for the suggestions guy, appreciate it. ill try some of that and i figured the syncros were simply **** form factory

 

Mine does it from 3rd to 4th at high revs so i've got used to pausing a second before shifting up into 4th. Yes, the syncros are know to be weak, a fluid change will help but in reality you have two choices, shift slower or get the trans rebuilt.

I can live with mine as we're talking 80mph+ when mine does it so I've pretty much finished my acceleration but 1st to 2nd must be a pain!

 

Same here, at higher rpms from first to second it does grind and now it's been starting to get worse,even normal driving from second to fourth It'll grind and not go into third. 92k miles on it atm. Transmission rebuilds are expensive

I also changed my tranny oil at about 80k Miles and it helped it out just a bit but still same issue

 

Have you tried adjusting your clutch pedal free play?

 

change transmission fluid.
check your clutch pedal bracket for any damage.
check your brake fluid level.

 

my 2005 is fine. Shift it during rev limiter like butter.
New synchros id sugest.
This usually occurs from newbs shifting from 4th to 5th and bang it into 3rd. (common newb error)
Being that these cars are made lightweight & precision accuracy~ i can see one of these mistakes will cause this error.

Cheap fix is Different tranny lubes~ but you can order stock synchros & get it rebuilt (by a pro).

 

If you're thinking about ordering them, I found this site here

Manual Transmission Parts - Online: Standard Bearing kit WITH Synchronizers, RX8 transmission

idk if you guys know any other websites that are cheaper. If you do, post it on here

 

Exactly the same problem with my car. Bought a used one with 80,000 km. can't handle the annoying grind anymore