Thread: Trans cooler lines, which is IN and which is OUT?

Okay, moved over to the 4T65E section.

Only the feed side or fitting point straight down has a checkball and this is only on SOME 99 and ALL 00+ cases until early 04. 97-some 99 cases do not have the checkball. IF your case has a fitting with a checkball then it must be retained. These cases will have a larger thread on the feed side than the return side. There are fittings that accept the threaded cooler lines that do have the checkball and will work in a quick connect fittings' place.