Celica St '94 Where Are Located The Detent Ball Spring?

[h4rfang]

Hi, i have a celica ST '94 (1.8 7A-FE M/T with C52 transmission...) and recently the 3rd speed pop out of gear... before doing anything i want to check if all detent ball spring are ok but when i look a the top of the transmission i see only 2 plug!




Here are the 2 plug i can see on the top of the transmission:


here you can see the inside of the transmission:


finally here you can see that there are 3 plug, 3 spring and 3 ball...




my question is: Where Is Located The Missing Plug For The Detent Ball Spring?

Thank You!