4x4
What is a primary mount? You have an inner primary, outer primary, inspection cover, and derby cover.
The derby is the cover on the left side of the bike where the primary oil goes. It'ts called a derby cover,
Harley Davidson "Derby Cover"A "Derby Cover" is basically a dust cover. It's on the left side of your bike and covers the business end of your clutch. It's the larger cover with (usually) 4-6 screws holding it in place. However my '85 Sportster has no screws in the "Derby Cover". Instead there's a two inch (2") screw-cap in the center of my "Derby Cover" with a large closed slot in the center. That's it! there are no other screws holding it in place.
most likely a 10mm or a 3/8"
count the number of bolts on the differential cover. this will determine the size
remove the derby cover from the primary. Fill until it tries to run out. Replace derby cover.
remove the derby ( round ) cover from the primary. fill til it tries to run out. replace derby cover.
remove the derby (round) cover from the primary. fill until the fluid tries to run out. replace the derby cover.
10mm or 12mm metric 10mm or 12mm metric
the large round cover on the rear of the primary three screws over the clutch
The "Derby" is the large dome-shaped cover on the primary. The primary is on the left side of the engine. Be VERY careful when removing the derby fasteners. The screws on the derby are very prone to stripping. Insure that any tool is inserted all the way to the bottom of the slot before placing any force on the fastener.