This works well, Only design flaw is at the connection at the fitting that joins the flexible "hose" to the actual body of the oiler, If it is not on tightly and perfectly aligned it will leak. I fixed mine with some permatex, Othewise this work and does what I need it to do....fill my hard to get to transfer case with trans fluid! I am guessing transfluid leaks easer that regular oil, so it may be my application that is not working well with this oiler. I would recommend this either way...way better than others that I have purchased in the past.