I read a good article on how to flush the fluid on the 4r70/75e transmission. However, I was wondering if anyone knows if you are supposed to clear the cooler lines during the flush? Also, does the torque converter fluid need to be changed?

 

The bulk of your tranny oil is held in the torque converter so you definately have to flush it. I read an article that sounded pretty good but it required that you run the engine in order to drain all the oil out of the tranny (that part concerns me as a new tranny is over $3K). Dealer charges $180 to $200 for the job, you may want to consider because if something goes wrong its going to cost over $1K just to take it apart.

 

Thanks for your help, I just got a manual for the truck, I will check it out.