This might be a stupid question. Why is there two oil filler caps on the engine? One is in the normal location top of engine the other is on a seperate assembly on the right side of the engine. Both are orange caps labled oil.
I find this alot on tractors. The side one is just an easier service port. They both fill the same case but sometimes the top one is hard to get to on some tractors.
The reason why is because, whether its a Kukje or Cummins A-Series, the engines that are used are also manufactured and sold for use in smaller, industrial equipment. They put two on there just in case if say the top or side of the engine was blocked by bodywork you would still be able to fill it up with oil.
It's a universal thing. As stated allows the engine to fit other applications.
I have a Kohler Marine Generator with a 4 cylinder Kohler engine. I has a fill point on both sides and a dipstick on both sides also. This allows the Gen to be installed right,left,front or rear.