2004 Quadra Trac II Question

[reesings]

I am a four wheel drive newbee who recently bought a 2004 Grand Cherokee with Quadra Trac II. When climbing a steep hill on the street leading to my house during a snow storm, the rear wheel seemed to slip most of the way up the hill. Although I didn't get stuck, there was some fishtailing and the rear wheels continued to spin. It has happened in other similar situations as well. I am wondering if the Quada Trac II is working properly as I thought as soon as they began to spin power should be sent to the front wheels to compensate. I plan to go to the dealer next week for routine service and plan to ask a technician about it, bnut wondered if anyone has any thoughts on the subject.

Thanks

Richard