After trying all kinds of plugs, o-rings and copper/aluminum/fiber sealing washers on my truck and customers trucks the one that has work the best has been the PLUG IT RIGHT drain plug but with a nylon washer. Here is what happens when the stock drain plug has been over torque: the flange is too thing causing the center portion to thread in and allowing the flange to bend out, at the same time the sheet metal on the oil pan pulls in, this part of the oil pan that is now pushed up is the area where the stock sealing washer seals at, that is the reason why most of the time you can't get it to seal after you install a new stock drain plug and washer. If you continue to use the old plug with the deform flange its only a matter of time before the flange brakes and you loose the oil. The main trick to get it to seal was to find a soft sealing washer that was the same size or bigger than the diameter of the flange. I tried copper and aluminum washer but it require about 50 lb ft to get it to seal. The fiber washers were the same but some required up to 60 lb ft. As you can see the stock drain plug flange is not strong enough to take that kind of torque. These tests were done with some test plugs that were made at a machine shop at a high price, $25. I came across the PLUG IT RIGHT drain plug During May-Madness and realized they already had a plug that I was trying to make to market and it was way cheaper that the ones I was working on. The only thing I did not like was the fiber washer that was supplied, it did not seal on my truck until 55 lb ft. I then started to search for a nylon washer, with the help of Dkevdog (Kev) we came up with one that had the perfect thickness and OD diameter but smaller ID. I ream the ID to fit the PLUG IT RIGHT drain plug and installed it. The sealing washer seal at 20 lb ft, I was not sure if I wanted to leave it at that torque so every other day I bump the torque to 5 lb ft more and stop at 40 bl ft. I do not like the idea of having to ream each washer so I'm still looking for some one who can make this in large numbers. If any one know of some one who can help me on this please get in contact with me.
Pablo