hmmm, why is that tubing so bunched up there? Its in reverse in that pic right? The servo horn shouldn't be at a 90 degree angle to the servo body in forward or reverse, it should be at about a 45 degree angle... if you have the servo horn on so that its in gear and the servo horn is at a 90 degree angle instead of 45, it could be putting stress on the linkage and making it slip out because it wants to move further than its able too move... Also, it looks like you may need to move the linkage (the one with the loop that moves the module lever) so that its more in the slot of the module linkage.... is it as far as it will go?