tchubacha

Upshift is fine and double clutching it helps a little bit but still not smooth when trying to downshift. Transmission was refreshed about 15K ago with the installation of the OS Giken LSD over a year and a half ago. One of the synchros was cracked and was replaced then. Replaced fluids (Redline 15w90ns) and there was a small mushroom size shavings on the drain plug. I know, should have taken a picture of it. So bad synchros? I see the DIY to drop the transmission without the engine on a C2, any other issues on a C4S? Don't want to drop the engine again if I don't have to.

No HTwo O

A better trans fill would have been Mobil Delvac 75W90.

Your 15W90 sounds "thin".

tchubacha

Mistyped, it was 75w90ns. Was still in engine oil mode with the "15"