This crush washer should do the job.....
http://www.finishlineperformance.com/store/product.php?productid=16914&cat=273&page=1
What fluid are you using?
The RX-8 appears to be sensitive to fluid choice and can get some early synchro wear/failure without the "right" GL-4 transmission fluid.
http://www.finishlineperformance.com/store/product.php?productid=16914&cat=273&page=1
What fluid are you using?
The RX-8 appears to be sensitive to fluid choice and can get some early synchro wear/failure without the "right" GL-4 transmission fluid.