alot of this guide helped me to understand use it as a template make small changes an keep scanning till you have it where you need it. How To: 4L60/65E trans tuning. Shifting/TCC/TM (w/ Pics) - HP Tuners Bulletin Board but first and foremost you need to keep in mind that if your transmission has a lot of miles on it or has slipping issues already etc....you may just wana hold off tuning till your transmission is in proper order.