The 38060 manual is not available from the Toro site.
You can get the manual for the 38080 from the link below which is close using a serial number in the 8 million range. The only manual available is the owners but it does have some adjustments procedures.
The 38060 came with 3 for ward and 1 reverse. The 38080 had 3 forward and two reverse but I think both used two drive disks and the dash and linkage controls the same. The interlocks are probably the same.
https://homeownersolutions.toro.com/portal/server.pt?space=CommunityPage&cached=true&parentname=CommunityPage&parentid=1&in_hi_userid=19462&control=SetCommunity&CommunityID=214&PageID=238#productDetailsPage