Im reading the messages, looks like that nobody answering your question. I know this problem from 240/740, I think the 940 is the same. Your overdrive solenoid does not work. the problem is if the solenoid does not work the tranny will go up to the 3rd speed, and will not go to the 4th one. Im at work, I have my paper how to solve this problem at home, so if you are still interested, please write me an email, and I will send you how to solve your problem, a) for no expense if you want to fix it such way then the overdrive will always work, meaning that you can not limit the tranny to the 3rd speed, b) fixing it correctly, exchange the overdrive solenoid. My emailaddress is gabehauer@ yahoo.com. I solved the problem such that the tranny always goes from 1st to the 4th. Happy bricking Gabe