Has anyone had a rear trans. seal leak , could I use some kind of stop leak? 2004 Liberty 3.7 eng auto, 2wd

no its not a good idea to use any type of stop leak

I back Matt up on this one.. Adding any sort of stop leak or fluid modifier to the transmission is going to change the properties of the fluid and cause valvebody components to stick or malfunction, among other possibilities. If it's a minor leak, just live with it. If it becomes major, replace the seal.

if its right at the rear the seal is real easy to replace if its in the tail shaft housing alitle bit harder but stil take the slip yolk out and se if thers a grove give me a call at driveshaftsuperstore.com and il hook you up wth a new yolk we stock those pinion yoks