Fram PH7575 is what I use on my STX38.
how do i check the hydro transmisson fluid on a stx38
eat S_H_I_T
30 lbs
On the deck
stx 38 fly wheel
I can not find one either
Go to http://outdoorpowerinfo.com/repairs/deere_stx38_gear_drive_belt.asp for pictures and descriptions of installation of drive belt and deck belt for John Deere STX38 Tractor with black mower deck.
bladebelt diagram for john deere stx38 yellow deck
Outdoor Power Equipment Website
moostxc255457
The yellow deck STX38's were made from 1989 to 1993The black deck STX 38's were made from 1994 to 1997