Can't Speak for all Twin Cams but on my 04 Heritage is between the shocks underneath the frame..
The 2003 Harley-Davidson Heritage Softtail transmission drain plug is on the bottom of the transmission. The drain plug is flush with the bottom of the transmission. You can remove it with a half inch ratchet.
On a 1993 Harley Davidson Low Rider custom, the transmission drain plug is underneath the transmission. The filler plug is on the side of the transmission case.
The oil drain plug on a Harley Davidson 003 Dyna Wide Glide is located on the left side of the oil drain pan. The right side contains the transmission drain plug.
The 2002 Harley-Davidson motorcycle transmission drain plug can be removed with a 9/16 socket. A five-point socket will work the best
The motor oil drain plug is located on the underside of the transmission, closest to the right side of the bike. The one closest to the left side is the transmission drain plug.
The plug on the shifter side is the oil drain plug. The one on the braking side is the transmission fluid drain plug.
one is engine oil drain plug and the other is transmission oil drain plug
Sitting on bike, left hand rear part of drain pan. The plug closest to the center of the trans side cover is the transmission (24ozs) drain plug
it the 5/8 hex bolt on left front of the sump pan. you will need 1 quart of Harley Transmission and primary oil.
Drain plug on the bottom
The transmission drain plug is located on the left side of the bike as you are sitting on it, right behind the front foot peg. It is a 16mm hex head bolt.
On the front of the oil pan, under the transmission,on the side by the primary. Get a manual.