No its not a drain hole (I found this out the hard way) but it is some sort of service / Tooling hole?? Anyhow, its underneath the cobra emblem on port side of upper part of leg (DONT TAKE YOURS OUT) The plastic seal was cracked and it was s huge pita A$$ to get the bar back in, plastic plug in place and nut into bar from the first pic. I used an expansion plug in second pic that I picked up from ACE hardware for about $5.00. I cut about 1/4 inch off of the rubber (Did this to make sure water flowed well in leg and didnt stick to far out on outside) and stuck it in the hole. Then cranked it down, cut remainder of the bolt off that was sticking out and the last pic is how it turned out. Any questions let me know!!