when you change your transmission fluid you only change about 50& of the oil thats in there unless you get a tranmission flush. i want to put synthetic oil in it but the remaining 50% of the old oil will not be a good combination with the synthetic oil, how can i completly drain the old oil without refering to a costly transmission flush

 

not possible, a flush will be a cheaper way to do it then overhauling the trans


I have heard of people draining the pan, filling it back up, and cracking a cooler line while keeping the pan full, but I never liked this method

 

most trans flushes are not that bad, i charge
$79.95 for regular fluid and $130.00 for amsoil. most shops will use the fluid you have if they do not stock it. always use 10% more fluid to help get a little closer to 100% exchange. for your i always use 13 quarts

 

why not?

and yea its probably easier to just buy your synthetic atf and pay someone to flush it with a machine

which btw, doesnt replace 100% of the old fluid, but gets really close

 

What is a good interval for changing the fluid, not flushing it?