My friend put some GM Syncromesh tranny fluid into his rx7 and it makes the cars shift very smooth. I've also heard many otehr good remarks about this tranny fluid. I looked on the bottle and couldn't find anythign regarding the GL of the fluid. I remember reading somewhere that for our trannys we shouldn't use GL-5 fluid. I'm due for changing my tranny fluid out (currently Redline MT-90) and was wondering if it would be safe to put GM syncromesh into my tranny.