99 u270, looking at the engine, left side has a big container with pipes to the (transmission?) there is a small cap on the top with tighten loosen printed on it. <br/>There is a small amount of oil coming out of the cap which is as tight as it gets, if I loosen the cap it is still attached in place and does not appear to be removable<br/>What is it?<br/>Is this a problem?<br/>What do I...