TVH supplies a lot of parts for old Clarks. I think most of the transmission wear parts are available.

Thanks for the direction and information, are the parts for these old machines still available? Id hate to get it all tore down and then cant find parts?

You have to pull the transmission. Only access is through the hole left when you remove the control cover.

Thanks for the reply, I was kinda afraid that might be the case: the linkage appears to be pulling the spool valve up fully, I disconnected linkage and pulled it up manually too,
On these machines, can you pull the engine to service the clutch packs from the front of the transmission or is it best to pull the transmission out? Thanks for the info....

Usually on these machines a loss of one direction indicates a broken seal ring or a burned up clutch pack. Make sure the directional spool is fully engaging in forward.