Why is oil collecting in the primary case of a 1976 flh?

Answer 1

I'll imagine it's a stock 74 cu in motor or larger due to mods of your own. If it has a stock oil pump, primary etc then oil is sent ot the primary chain for lubrication then it goes back into the motor or oil. There should not be a lot of oil in the primary (stock "dry" clutch). So.....you may need to check and see if the return line from the primary to allow the oil to flow out is clogged possibly or you've got a pump/return line etc problem.

Newer primarys are basically sealed (wet clutch) and hold oil in them. Different amounts in ounces. My 1980 has the flow from engine and back into the engine primary like yours. I changed mine by removing the in line from the pump (curved about 90 degrees with a rubbler line going to the top in the back of the primary to squirt/pump oil on the primary chain and plugged the return line to the motor. I didn't like pumping oil into the primary and back into my engine oil so I "sealed" my primary (shovels seem to always leak, keep an eye on it) and put 4 to 6 oz's of primary oil in it. The oil will be "splashed up on your P chain but you can't use too much due to the dry or wet/dry clutch .