I am trying to understand whats going on, are you talking about the valve on the side near the manual valve, the little one on the end? If so then yes this is the forward clutch control valve. If it has broken it retaining clip or is damaged it could cause a no forward engagement. I have seen problems with that valve before.

If it has a spring between the valve and end plug remove it, this will help with delayed forward engagements

ATB620.pdf