[EclipseGST]

Do you replace them yourself? If so, take the tranny apart and check the retaining clip that put tension on the 3 keepers (keys) that lift the synchro when shifting. I had them spin on 1st thru 3rd gear and it wouldnt allow me to put it in any gear without it poping back out or grinding. Put the retaining clip back on the right way and presto... shifts beautifly now. Just a thought on something to check before you start buying parts if you dont really need them. Just my $.02~

To use the double synchro you need the whole kit from TRE cause you get a modified 2nd gear for the synchro to fit, that is where I got mine from also. It was about $325 for FWD or AWD and the benifit of it is smoother shifting and it allows you to shift at a lot higher RPMs from what I have experianced. I guess they say it is suppose to be stronger and outlast the OEM ones too. I have mishifted it and it still is fine for me.