Saturn Overdrive shifting issues

 Saturn Overdrive "Jumping" out of direct. When the Saturn is in direct drive, the shifter slider ring is engaged with he planetary hub. The following is a list of all causes: 1) Verify the planetary hub protrudes a minimum of .677" from the face of the Dana 18. 2) The Overdrive shift rail has an overall travel of almost 1" shifting between overdrive & direct. If not, check for possible broken shift fork. 3) Do not double up on the aluminum housing gasket to Dana 18 case or use an excessive amount of RTV with the gasket. 4) Excessive transmission end play could cause the overdrive planetary assembly to "walk" and allow the overdrive to "jump" out of direct. Also verify that the planetary housing special nut is torques to proper specifications. 5. Assuming all the above criteria have been met, verify the internal splines of the shifter slider and / or the boat teeth on the planetary hub are not damaged. Grinding during shifting will cause excessive wear. Saturn stuck in overdrive. The drive member is engaged into the aluminum case cover. Older / High mileage units become "loose" and generally do not experience this problem unless there are damaged components. The following is a list of all causes: 1) Verify Overdrive detent ball & detent spring are installed and / or not damaged. 2) Check shift shaft for damage 3) Damaged / broken shift fork. The overdrive shift rail has an overall travel of almost 1" shifting between overdrive & direct Saturn "Jumps" out of Overdrive: The drive member is engaged into the aluminum case cover 1) Verify Overdrive detent ball & detent spring are installed and / or not damaged. 2) Verify Overdrive shifter clearance to Jeep body. 3) Damaged / broken shift fork. The overdrive shift rail has an overall travel of almost 1" shifting between overdrive & direct