Bests & Worsts Reviews from Amazon

I'm not a chemical engineer but I do understand a little about how this product works I think. It contains polymers that are absorbed into rubber seals/bushings, etc. If you spray it on something like a rubber motor mount and look at it a little later the mount will be dry again but will look a little less dry and aged. So, say your transmission fluid is old and full of micro particles of rubber from seals/rings it only makes sense that the floating particles are going to absorb the polymers and possibly get big enough to clog a fluid path or cause some other issue. If you have an irregularity in a seal thickness this product might make things worse because the irregularity might become worse as the seal expands unevenly. It helped my oil leak but I would "never" put this in my transmission because my car has 320k miles and the transmission fluid is old and probably full of junk and tiny rubber particles. So, that's why I think you've got such a huge divide in the reviews here on how well this product works....