Lancer 1991 CB Auto Slipping

1st and 2nd gear are slipping in the Lancer. Car wont move forward, but reverse works fine. If you can get the car to speed (roll down a hill) 3rd gear will kick in. Been trying to get any info on what might be needed to fix this problem. Thanks in advance, I havent been able to find any information on the CB model at all.
 
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