same o-ring trick cost me a $5000 RTV engine.
On the rtv 1100's you can't really get to the filter very well. It's a bear, unless you do it from the bottom which requires removal of the skid plate. As a paid technician, I don't take the skid plates off unless completely necessary. On that particular one the skid plate was completely packed with dirt anyway which makes it even more "fun", so I reached down in there from the top, removed filter, installed new filter, refilled with the correct amount of oil and started the engine. Everything was fine. No leaks. Rechecked oil level, drove it around a little and gave the RO to service manager as "done".
Several weeks go by after it was picked up (commercial users).
I get a call saying that "I just had my RTV in there and it's making a noise and not running very good and smoking". Ok, can you bring it in? NO WE ARE IN OKLAHOMA ON A JOB. Great, check the oil and make sure it's ok. I was assuming maybe they ran a stick or something up into a filter or hose ow whatever. Another couple weeks go by, it shows up. Won't even run now. Dropped off, I look down at the engine and there's a hole in the side of the block where the rod broke off. Apparently in the haste and inaccessibility of the filter change I didn't check to see if the old o-ring was stuck on the block or? Sure enough it was double gasketed and it blowed all the oil out after they used it a while. Of course they continued to use it as most commercial hired helpers do, without bothering to check for fluids running out of the bottom and seized the engine-apparently many times since it broke the rod off and sent it through the side.
I bought the engine...my mistake and I owned up to it.
I use this post to remind folks of two things. One, techs are people too and therefore imperfect. Two, double check the o-ring after the filter is removed!!! And three, engines are expensive...so are transmissions.