I've had the z6 swap for most of the time I've had the hatch. It shifts just fine under normal and even moderate driving but especially when I get it up between 5k and redline, when I shift into 3rd/4th it grinds and just feels rough going in. Please just a few hints or suggestions as what's going on with it would be awesome.

 

syncros are worn maybe change the MTF with some fresh honda MTF or you could get some GM syncromesh Friction modified stuff that everyone on here loves, if its still grinding you will need to replace the syncro or tranny. I have never used the GM stuff so I can't tell you if it will do what your looking for, but the trend on HT seems to be that it will remove mild grinds

gl

 

^^^^argh, I've replaced it twice and it has mobil 1 5w-50 in it now.. I'm sure there's a thread about replacing synchros and swapping the tranny right??

 

I don't think you should use synthetic in your tranny also you may want to try the recommended weight of oil if your going to use regular oil its 10-30, replied to your IM