I just finished my tpi swap into an 86 k5 and I went for a drive.I started out with the trans in 1st(low)just to run it through the gears and it automatically shifted into 2nd when the rpms got up to around 2000.I wasnt flooring it or racing around just wanted to get everything moving again and then this happen.Inever heard of anything like this before has anyone else?Im hoping it dosent need to be rebuilt already only about 35,000 on this rebuild.Can anyone help??????