Ok, it may not be a drain plug , or the clutch, I've searched TMs and can't find anything. Looking from the underside, between the engine and the transmission is a large round/drum which is missing what I imagine would be similar to the oil pan drain plug. Looking for guidance on what this component is, purpose of the 'drain plug' and any info on replacing. Happy to do my own research if pointed in right direction. Thanks in advance for any help.